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Wednesday, 18 December 2013

'Tis the season of seed cleaning

Weeks ago, Nick suggested I come in on a rainy day to the garden as there was lots of seed cleaning going on in the potting shed. Then it didn’t rain for three weeks. Defeated by the glorious Autumn weather we’ve had, I phoned Froggie, and asked whether I could come in to learn about seed washing...yes, that’s right, I said “washing”. I’m such an amateur! However, Froggie was kind and  refrained from laughing at me and just said, “we don’t really wash the seeds unless they have a particularly fleshy covering”.

We arranged a time for me to come in and, as it happened, it was yet another glorious sunny day. While this made for a nice bicycle commute for me, it meant that the volunteer gardeners were all out in the garden so I would be having an individual, hands-on learning experience with respect to seed cleaning.

So many envelopes

As Froggie and I entered the potting shed, she took me immediately over to a bench lined with trays in which rows of envelopes were stacked up. On the outside of each envelope is written the plant’s latin name, the family name, the year the seed was collected, which collection the plant is from, the accession number and a number that corresponds with its numbered listing in the Garden’s Index Seminum. This is a catalogue of the seeds and spores that have been collected in association with the University of Bristol Botanic Garden. This catalogue goes out annually to the Friends of the Garden, other Botanic Gardens and research institutesRequests can be made for small quantities of seed for the purposes of research, breeding, conservation and education, or by members of the Friends of the Garden (subject to certain conditions).

The Garden likes to keep three years worth of seeds, but obviously different seeds have different storage potential. Some species, such as those in the Apiaceae family, which includes celery and parsnips, are generally only viable for a year, while other seeds have been found in archaeological digs that are estimated to be thousands of years old and have remained viable (see the 2,000 year old Judean date palm as an example).

Separating the seeds of Salvia forsskaolii. 
“We’ll keep back older years from groups such as the cereals, oats and wheat, as well as beans and peas,” said Froggie, “as they will likely remain viable and it’s good to have a reserve.”

Froggie explains that with the Garden’s involvement in the Seeds of Change project, there are even more demands on their seed stores. Though schools and community groups are encouraged to collect their own seed, the Botanic Garden is sending out lots of seed to start the projects off or replenish projects where collection efforts haven’t been successful.

In the little office at the back of the potting shed there are even more trays of seeds. This is where the staff compile all the seeds that go on the Botanic Garden’s annual seed list. Now having a sense of what the end product looks like, I sense that Froggie is about to show me how much work goes into filling each of these envelopes...

Separating the seed from the chaff

Pouring the Salvia seeds into a sieve to get
rid of the chaff.
I’m shown yet more trays of envelopes – but much bigger envelopes this time – many with stems poking out the top. The gardening staff and volunteers have collected the seed heads and placed them in these envelopes ready for cleaning and this is where the work begins. Froggie picks out the first envelope, it’s Salvia forsskaolii, commonly known as Indigo woodland sage.

We sit at the table, each with a white tray nestled within a larger black tray, which I assume is to collect the seeds that catapult out beyond the borders of my white tray. Froggie doles out a few sprigs of dried plant and shows me that the best technique for this particular plant is a simple flick of the seed head to help release the seeds. I flick and my white tray is scattered in small black seeds. Easy.

With the larger unwanted bits removed, we now pour our tray contents into a sieve to clean the seeds of any smaller bits. The clean seed is then poured into a smaller envelope that is placed back into the big envelope with the remaining plant material that is yet to be cleaned. When all the plant material has been worked, Froggie will then process the seed envelope, doing and final quality control check on the seed and making sure all the information is clearly written on the envelope.  

Nigella damascena before we begin to collect the seed.
We wipe down our trays and spray an anti-static spray to ensure there is no contamination as we move on to our next species – Nigella damascena. This too requires a tapping method, though some persistent seeds need to be squeezed out. There are numerous implements on the table for crushing plant material to get at the seed, but Froggies says they try to discourage crushing as much as possible as it makes for a lot of fine chaff that is difficult to separate out later.

As we work, Froggie fields questions from the volunteer gardeners who are looking for equipment or just confirming that what they’re doing is right. As we work, Froggie relays a few stories about misguided efforts of volunteers – stories of pruning gone awry or cutting back incorrect species – she chuckles about it all and has an ‘it all grows back’ sort of attitude about it. I know Froggie no doubt has a million other things she needs to be doing, but she gives me her full attention and focus and makes me feel as though she has all the time in the world for me. She creates a calming atmosphere, which no doubt comes in very handy when coordinating the efforts of so many volunteer gardeners and teaching new skills.
What my tray looks like after I've removed the Nigella seeds
from the seed heads. 

There is quite a bit of fine material mixed in with the Nigella seeds and so Froggie introduces me to another technique for separating seed from chaff. She takes some newspaper and folds it in half and pours seed and fine chaff together onto the paper. Then with a motion not dissimilar from a chef tossing almonds in a skillet, she carefully tosses the seeds in the paper. The fine, lightweight chaff moves to the top of the crease in the paper, while the heavier seeds move down. She can then simply give a very gentle blow to get rid of the chaff off the top of the paper. In the end she’s left with just the clean seeds.

We start on the last one – Avena orientalis – a grass. For this seed you hold the spikelet in one hand and flick the seed out. This particular species has a lovely dark seed, so it is very clear when you’ve got it all separated. 

Froggie uses newspaper to separate the lightweight chaff
from the heavier Nigella seeds.
Not all the seed cleaning is this easy. There are dust masks as some can be particularly dusty – but the staff tend to do the really nasty seed cleaning themselves, letting volunteers do the easier ones. If this were a rainy day, there would be volunteers everywhere working on this and having a good old chat.

Looking at the stacks of envelopes, I ask Froggie when seed cleaning needs to be finished.

“We need it all complete by February at the latest,” Froggie replies. “The seed list goes out in February and people will start to put requests in. We also start sowing at the end of February, beginning of March.”

Checking the lists
Cleaned Avena orientalis seeds with the
lighter leftover spikelets in the background.

In many of my excursions to the garden, the staff have introduced me to the many lists that they keep. There is a seed sowing list, a putting the garden to bed list, and now, I have seen the seed collecting list. This is where the staff make notes against each species – for example, if a plant was too small or late to come into flower. These notes are kept year to year and so if a species is less productive in one area of the garden than another or from one year to the next, all of this information is captured.

“The list is never finished,” says Froggie. “I will just update it when something else changes.”

In years where they are unable to collect seed for a particular species, they draw upon their reserves from previous year so that it can remain on the seed list. Annuals tend to be a priority, but also shrubs. The Garden works hard to insure that there is variety on the seed list.

As a member of the Friends of the Garden myself, I now look forward to receiving the seed list next year and I will have a much better appreciation of the work that goes into collecting the seeds for each of the nearly 200 species listed.


Monday, 25 November 2013

Forests may be more vulnerable to pests and disease in the future

As I sit in my home office watching the autumn rains and winds strip the last remaining colourful leaves off the trees outside, I find myself in awe of the tree. There’s a primary school across the street from my house and there are several huge beautiful chestnuts in its grounds where I watched the children shelter from the sun on hot days. There’s also the spindliest little apple tree that one could imagine, which despite its size produced at least a dozen enormous apples this year!

Trees affect every aspect of our lives – they provide food, timber, pulp and fibre, but beyond this they have important ecosystem functions in the natural landscape. Trees help to regulate our climate, they store and sequester carbon (about 30% of global CO2 emissions are absorbed by forests), they store water helping to prevent floods, they purify water and they provide habitat.

However, widespread pests and diseases have taken their toll on natural forests over the past century with outbreaks seemingly becoming more frequent and widespread in recent years. There has been considerable focus on the devastating effects of these outbreaks on trees with large economic value – orchards and timber plantations for example – but what are the consequences of the widespread death of our forests in terms of ecosystem services?

Oak in its autumn colours.
A review published recently in the journal Science considers this exact issue. UK researchers from the Universities of St. Andrews, Cambridge and Oxford reviewed the consequences of tree pests and diseases on ecosystem services around the globe.  The authors concluded that our current approaches to pest and disease management do not take into account the ecosystem services or the beneficiaries of these services provided by forests and that new approaches are needed, particularly as the likelihood of pest and disease outbreaks increases as a result of global climate change and globalisation.

Who’s attacking our forests?


Trees are attacked by any number of pests and diseases, including bacteria, viruses, invertebrates, water molds and fungi. The effects of these pathogens may be compounded as well; trees that have been defoliated by insects may be more vulnerable to disease.

Millions of years of co-evolution have generally allowed trees to build up natural defenses to the pathogens they encounter in their native environments.  However, the introduction of species or the movement of species outside their historical ranges has opened up a whole new world of pathogens that have been the cause of the most devastating attacks on our global forests in the last 200 years.

The American chestnut (Castanea dentata) was devastated by chestnut blight – a fungus accidentally introduced to eastern North American forests around 1900. In the early 20th century, over a quarter of the trees across approximately 200 million acres of eastern hardwood forests were American chestnuts, but by 1993 its frequency had declined to 0.5%. Today the tree is effectively extinct as very few mature trees are producing nuts.

Dutch elm disease – another fungal pathogen, which is transmitted by bark beetles – is familiar both in North America and Europe as it has eliminated mature elms (Ulmus spp.) from much of the landscape. Now there is concern that ash (Fraxinus excelsior) could suffer the same fate due to another fungal pathogen (Chalara fraxinea), which has been killing trees in Poland since the 1990s. Scientists are monitoring its spread to the rest of Europe.

The devastation wreaked on a Canadian forest by the
mountain pine beetle. Credit: D. Huber, Simon Fraser University
Public Affairs and Media Relations (Flickr CC).
As a Canadian I would be remiss if I didn't also mention the devastating effects of the mountain pine beetle (Dendroctonus ponderosae). It has already killed several million hectares of pine species in Canada and the US and they expect over 37 million hectares of forest to be affected in British Columbia alone before 2020.
Of course, with globalisation and the widespread movement of plants and plant products around the world, the frequency and spread of pests and disease is only likely to increase. Climate change will also improve conditions for pests and disease as milder conditions in some areas may let some pathogens increase their natural range, or may permit pest populations to explode in numbers.

Attack of the Frankenfungus


When pathogens move around the globe they are not only introduced to new hosts and plant prey, they can also escape the natural predators and diseases that keep their populations under control.

This global movement also exposes pathogens to new genes that can make them even more virulent. For example, when the fungus that causes Dutch elm disease, Ophiostoma novo-ulmi, spread across the northern hemisphere, it hybridised with a native fungus species (O. ulmi) and acquired some new genes that decreased the elm’s ability to resist infection.   

What does the loss of dominant tree species mean for our forests?


Widespread loss of a dominant tree species can have devastating effects far beyond any economic value they may have had. A wide range of ecosystem services will initially be harmed, such as retention and purification of water, wildlife habitat and carbon storage. Large stands of dead trees also become fuel for wildfires, which are far less specific about their victims and further alter the ecosystem.

However, inevitably the lost trees are replaced by new species and as this natural succession occurs some of the ecosystem services will be restored – carbon storage and water purification, for example. Unfortunately, other ecosystem services may never be restored. New tree species will create different habitats altering the biodiversity. 

Some ecosystems are particularly vulnerable as they are dominated by a species that plays a critical role in maintaining the structure of that ecological community – known as a keystone species. Boreal forest (or taiga) is an excellent example of this. The conifers that dominate the northern latitudes of boreal regions are adapted to short growing seasons, recurring disturbance from storms, fire and floods, and growing in peatlands. Loss of any species in these regions would have a significant impact on the ecosystem structure.

Climate change packs a one-two punch for forests


Not only does climate change have the potential to increase the numbers and range of pests and disease, it can also make forests more susceptible to these infestations. Though the future is uncertain, predicted increases in extreme weather events – droughts, floods, cyclones, and extreme temperature fluctuations - are likely to put our forests under severe stress, increasing their vulnerability. 

Of course, some pests may also be hindered by climate change. For instance, species that rely on an insulating blanket of snow to overwinter may be more vulnerable if snow cover is reduced in a milder climate scenario.

What is the future of our forests?


Nobody knows the answer to this question. However, the UK authors of the Science paper bring to light the need to do more fundamental research in understanding how pathogens affect natural forest communities. To date, most research has focussed on economically important species, yet the ecological role of forests and the ecosystem services they provide have considerable value also.

The long life span of trees has been a barrier to understanding some aspects of the infection and spread of some pathogens; the time it takes for some trees to reach a reproductive stage could outlive the careers of some scientists. However, new methods in molecular biology are overcoming these barriers these days. Understanding the process behind these pathogens will help in the prediction of their spread as well as how they may respond to climate change.

The authors also call for better management approaches that identify different classes of threat, which are defined by (i) the type of disease-causing agent (e.g. fungus, bacteria, insect), (ii) how it moves (e.g. wind, water, animal, wood imports) and (iii) the type of ecosystem service threatened (e.g. keystone species, timber value).

Management practices can also help build resilience in our forests. For example, practices that help preserve the genetic diversity of species and avoid monoculture will provide the genetic foundation that will help species resist disease. Steps to mitigate climate change may help reduce the abiotic stress on forests and reduce the expansion of pest populations.


Though there remain many unknowns and the future is uncertain, the critical role forests play globally is clear. So, if you are able, get out into a local wood or forest today and appreciate it. Those trees are cleaning the air we breathe and the water we drink. They grew that apple you brought along for a snack! They’re doing a lot as they stand there, so appreciate it...dare I even say...hug a tree?!  Who knows, you might start a trend?!

The original paper is: Boyd IL, Freer-Smith PH, Gilligan CA, Godfray HCJ. (2013) The consequence of tree pests and disease for ecosystem services. Science, 342 (6160): doi 10.1126/science.1235773

The AAAS press release associated with the paper can be found here.

Thursday, 21 November 2013

An apple a day

by Helen Roberts

Name three things Somerset is famous for and most people will say cider, Cheddar cheese and the Glastonbury Festival. While I could certainly talk at length about cider and its versatility (particularly having enjoyed a lovely mug of mulled cider recently at bonfire night), it is where cider begins - the humble apple – that is the subject of today’s post. I live near Wells, in the heart of Somerset, and the trees in the apple orchards are positively dripping with fruit at the moment, a welcome sight for orchard growers who had a dismal season in 2012. It was National Apple Day on the 21st of October, and many places around the UK have been hosting events to celebrate England’s national fruit. Humans and the common apple have a long history together in terms of its cultivation and it is a familiar fruit throughout the world. Essentially, the richness of this sweet little fruit lies in its ordinariness.

A brief history of the apple


The (not so) humble apple.
The domestic apple (Malus domestica) is derived from both Malus sieversii (from Central Asia) and the crab apple (Malus sylvestris). The domestic apple is thought to be derived from Almaten in eastern Kazakhstan and the northern slopes of the Tien Shan Mountains. Apple taxonomy is highly complicated, and I shall save you the details, but the Malus genus is included in the Rosaceae family and has approximately 55 species, which are divided into intraspecific groups or cultivars.

Evidence of apple collecting has been found in Neolithic (11,200 years ago) and Bronze Age (around 4,500 years ago) sites throughout Europe and there is evidence for its cultivation as early as 1000 BC in Israel. Carbonized fruits dating from 6500 BC have been found at Çatal Hüyük in Anatolia and remains of both sour crab apples and a larger form, which may have been cultivated, have been found at lake dwellings of prehistoric origin in Switzerland.

It is thought that apple seeds were probably transported along the greatsilk trade routes from Central China to the Danube by travellers, either in saddlebags or in horses’ guts as early as Neolithic and Bronze Age times. The routes passed through Almaten and the northern slopes of the Tien Shan Mountains.

Improved forms of apples are thought to have developed in the FertileCrescent, which covers Israel, Lebanon, Jordan, Syria, and Iraq. Apple trees reached Palestine in about 2000 BC and from there, were taken to Egypt.

Apples were important in Ancient Greece and various writings give evidence of the propagation of apple trees. Homer in the Odyssey, written between 900 and 800 BC, describes a large orchard of both apples and pears. It is the Romans that are credited with developing apple cultivation and storage. They recognized the importance and profitability of orchards and brought apples, and hence orchards, to Western Europe. Many Roman writers mentioned various cultivars of apples in their writings.

During medieval and pre-industrial times monasteries became major centres for apple production, particularly for cider production. King Henry VIII imported many different cultivars during his reign from 1509 to 1547, including pippins from France. In the mid 16th century, Dutch refugees escaping from religious persecution moved to Kent and Surrey to set up market gardens to supply London, and planted orchards for this purpose. During the 16th century and early 17th century grafting was further developed in Europe with specific rootstocks being imported from France and then propagated in English nurseries. European settlers, introduced apple culture to North and South America, South Africa, Australia and New Zealand. The first documented apple orchard in the USA was planted near Boston in 1625.

Cider making


The word cider is derived from the latin word sicera which means ‘strong drink’. The first recording of cider making is from Norfolk in 1205, but it was common in many different areas of England, particularly the western counties of Somerset, Devon, Worcester and Hereford. Apples suitable for cider have a sweet juice and an acid pulp. The names given to cider apple varieties are lovely in themselves, varieties known as “bitter sweets” and “bitter sharps”, such as  Slack-me-Girdle, Foxwhelp, Lambrook pippin, Chisel Jersey, Porter’s Perfection and Royal Somerset.

Cider making takes part in late Autumn and the traditional method was to crush the apples between heavy stone wheels driven by horses. In the West Country the resulting pulp was then spread onto straw or wooden racks and cloths and a large sandwich or ‘cheese’ was made by laying one rack on top of the other. Set into a wooden press, it was squeezed repeatedly and the juice collected. I remember watching this method of cider production at a local farm as a child in Central Somerset. Today cider has made a come back and there are many smaller scale producers cropping up in areas of the West Country.

Bristol University has a long history of research into cider production at Long Ashton. The research station was originally set up to facilitate the development and improvement of West Country cider and formed the National Institute of Fruit and Cider (NIFC). Scientists identified the best apple varieties, growing conditions, and production methods for growers and cider-makers; many cultivars, such as Ashton Brown Jersey, orginate from Long Ashton.   

Weird and wonderful facts


Apples are very much entwined in our culture and history. Many popular apple-based phrases, such as “the apple of my eye”, “an apple a day keeps the doctor away”, “rotten apple”, “rotten to the core” and “upset the apple cart”, are embedded within our culture. Other words also have apples at their core (groan);  costermonger – a street seller of fruit – comes from the Costard apple. “Costard” means ribbed and gave rise to “coster”, while “monger” means seller.

Erika Janik, author of Apple: AGlobal History, said the apple is “Enmeshed in the folklore and history of nations around the globe, apples have been associated with love, beauty, luck, health, comfort, pleasure, wisdom, temptation, sensuality and fertility – all this in addition to good eating and drinking.”

Apples at the Botanic Garden


If you managed to get to the Bee and PollinationFestival at the Botanic Garden, you will have seen a small cider press in action. You may have also seen a potted orchard on display near the pond, featuring a number of varieties of apple, including Bramley, Golden Delicious, Lord Derby, Ashmead’s Kernel, Discovery, James Grieve, Spartan, Fiesta and Greensleeves. It was yet another example of how pollinators are critical to our food security – pollination of our orchards and the production of the (not so) humble apple.

Monday, 21 October 2013

A snapshot of autumn

By Helen Roberts

With autumn having finally kicked in, what better way to spend a sunny Sunday than drinking in the colours of the Botanic Garden and tapping into our creative juices. A few weeks ago, Nicola and I did just this, enjoying the Botanic Gardens’ September colours whilst also taking part in the watercolour course “A Snapshot of Autumn”. It was five hours of uninterrupted, child-free, creative learning for two enthusiastic mums!

'I straightaway learnt apples are difficult to paint...' -
watercolour by Helen Roberts.
Annie Morris, an experienced botanical artist and member of The Society of Botanical Artists and Society of Floral Painters, taught 17 of us on the day. The course doesn't require any previous experience, which was good as Nicola and I are both beginners in watercolours. Though neither of us have ever attended a course, both of us (I think) are confident putting pencil or brush to paper in other media.

Annie started with demonstrations on drawing and basic watercolour techniques. We crowded around her as she worked confidently and swiftly, first drawing the outline of the leaves in front of her, then applying her washes of colour. Annie had brought in a considerable assortment of cuttings as inspirational material; there were lovely sprigs of rowan with bright red berries, clusters of acorns and branches of apples and sloes to choose from as our subject matter. Nicola grabbed an oak cluster and I chose an apple branch and we both steered clear of the rowan sprigs, fearing the complication of all the pointy leaflets.

The majority of people on the course were not new to watercolours and had attended some of Annie’s courses before; some are currently enrolled in the traditional botanical art course being run on Monday afternoons at the Botanic Gardens. Most people just wanted to improve on their technique and enjoy a day of uninterrupted painting.

Nicola's oak sprig.
After selecting our foliage of choice, we diligently set to work sketching. Annie had endless tips – for instance; how to place the plant in a way so it sits in a natural position rather than like some specimen sprawled on a table.  When we were satisfied we had captured the essence of our cutting in pencil, we then took the plunge with the watercolours. I learnt straight away, as I took the paintbrush in my hand, that watercolour painting is very difficult; Annie made it all look so easy with her demonstrations. You can’t muck about with the paints, you have to think about light and dark before putting brush to paper. You almost paint in the negative, if that makes any sense, thinking about where you don’t want to apply paint rather than where you do. Once you’ve added colour you cannot take it away easily and you don’t use white paint in watercolours to add light.

Straight away I struggled with mixing my colours and my initial apple leaves were an insipid green. Nicola, on the other hand, was struggling with having to work quickly and with small bits at a time to avoid hard edges when the paint dries too quickly. Before we broke for lunch, Annie pulled us back to her desk to demonstrate how to add the finer detail – with a few strokes she was bringing her samples to life and giving them depth.

We spent lunch in the garden, soaking up the sun’s rays. We sat with a woman who had travelled from Monmouth and had done a lot of calligraphy, but not watercolour. She and her husband are members of the Botanic Garden and she thought the watercolour course was a wonderful excuse to visit the Garden.

Helen's apple branch - the product of five delightful
hours spent painting.
We returned to our work to add leaf veins, holes, fruit, nut and stem details. I straightaway learnt apples are difficult to paint and was muttering a bit about my choice of fruit. Nicola was stumped with adding detail to the acorn cup. However, after 5 hours we had produced something pretty acceptable. The final demonstration from Annie was a number of useful techniques, such as how to paint a water drop on a leaf – the result was truly amazing, so lifelike!

We all had a very inspiring day and I was pleased with my final painting. My 5-year old son wants to frame it! Both Nicola and I are going to be investing in some good quality brushes and enrol on Annie’s course in the winter. In the meantime, we’ll be looking to the beautiful colours on display this autumn to get inspired and do some more painting!

Thursday, 3 October 2013

Bringing the Levels to the Garden

If you’ve been to the Botanic Garden recently, you may have noticed an area by the pond that has been sectioned off with some ropes. This is the future home of the Somerset Levels and Moors display at the University of Bristol Botanic Garden.  It is one of the mini-habitats of areas that are found here in the West Country that the Garden is replicating as part of its display of rare and threatened plants.

The Somerset Levels run from the foot of the Mendip Hills through to the first rising of the Quantock Hills and occupy an area of about 150,000 acres. The Levels are an interesting habitat, which has formed as a consequence of some rather unique geological features as well as hundreds of years of human modification; they support a rich diversity of species and as a result are of national and international importance.

I had an opportunity to speak with both Andy Windfield, a botanical horticulturist at the Garden, and Nick Wray, the Curator, about the Levels display that’s being constructed and there is an incredible amount of thought and work that goes into it. It’s not simply a matter of taking some of the local species and plunking them down in the garden, Nick and the Garden staff are taking great care to replicate some of the natural processes, such as the seasonal rise and fall of water levels, that make the Somerset Levels such a unique habitat.  

What makes the Levels unique?

The Somerset Levels are a sedge-peat moor, which is very distinct from a sphagnum moss bog that you normally associate with upland areas in the UK or low-lying areas where there is high rainfall and little drainage. Whilst there are some sphagnum mosses on the Levels, it’s mainly sedges and grasses that grow there and this produces a different structure of peat.

Below the peat is an impermeable layer of clay that used to be the bed of a shallow sea. In fact, until the early part of the Middle Ages, large parts of the Levels were still part of an inland sea.  However, local people began to drain the area, creating dykes and ditches to lower the water level.

The Levels are still a catchment for the surrounding hills, which are comprised of primarily carboniferous limestone. This is very hard limestone and it’s hard to weather, making the groundwater running into the Somerset Levels alkaline. This is a unique situation because peat bogs are normally associated with very acidic water, yet the Levels are a sedge peat where the groundwater can be alkaline.

So, how do you replicate all this in the Botanic Garden?

First, Andy takes me out to the pond and we are standing near the rock garden – an area a child visiting the Garden once called ‘wiggly water’ and the name has stuck with all the staff here.  He explains that in 2005, when the Garden moved to this location, one of the first things they did was mark out this main pool.

“Nick started explaining what this was going to be,” explained Andy. “The main pool was constructed with the Levels display already in mind, with this side of the pond 5cm lower than the other edges. So, when the water overflows in the pond it runs down into this display area.”

The Somerset Levels display, with the large pond in the
background, has to settle before planting can begin.
 At the base of the display, they’ve put in a liner with a depth of about 30cm to simulate the impermeable clay bed. This replicates one of the key features of the Somerset Levels - the seasonal rise and fall of the water level.  In the su
mmer this display area will be allowed to dry out, but the liner below will create a reservoir below.

On top of the liner, they’ve put in truckloads of waste sedge peat (a bi-product from a former industry in Somerset). “It took staff and volunteers lots of time to move it in,” says Andy. “We’re now letting this sink and we’ll likely need to add more peat on top before it’s ready to be planted out.”

The rock garden around the wiggly water is comprised of carboniferous limestone and is planted with rare and threatened native plants of the Mendip Hills. It is not a mere coincidence that the Levels display sits adjacent. Nick explains, “Just as in nature the Mendip Hills are next to the Somerset Levels, here at the Botanic Garden the Mendip Hills are next to the Somerset Levels.”

Planting out the Levels

Many of the plants that the Garden will replicate in this area are grasses and sedges and small herbs. There are some shrubby species also and Nick points out a bog myrtle by the pond that was collected for the Garden in the 1970s from Shapwick. It has an incredible smell and not surprising as it comes from the same family as cloves, allspice and eucalyptus (Myrtaceae). Bog myrtle creeps slowly through the peaty soils and creates dense thickets in these peaty soils, so this will be one of the plants included in the display.

Nick also hopes to have a small area of some carnivorous plants because the round-leaved sundew (Drosera rotundifolia) grows in the Somerset Levels, as does the common bladderwort (Utricularia vulgaris). There will also be some ferns such as the royal fern (Osmunda regalis), which is a fantastic foliage plant that grows at the edges of the ditches in the Somerset Levels,

Some of the plants will be sown directly into the peat area once it has settled and been topped up, while others will be sown in little pots or plugs, grown on and then planted out. All seed and plantlet collection is being done with the permission of Natural England and Andy and Nick will be doing the collections themselves.

“One of the exciting plants we’ll be getting in here is a population of marsh orchids,” says Nick. “We already have those marsh orchids growing in our nursery and they’ve been raised from seed from an original collection back in the 1970s of southern marsh orchids. So we want a large population of deep pink and purple orchids.”

Once mature, the main flowering interest in the display will be late June and early July after which it will go to seed and then be cut in August to tidy it up. Then it will be allowed to be wet and grow slowly through the winter months.

Planted in the ordinary soil around the peat area, there will be species of willows, which are common to the area, including the almond willow (Salix triandra), the goat willow (Salix caprea) and, if there’s room, the common osier (Salix viminalis)> These will be coppiced so they don’t get too big.

The sweet track

The sweet track is a very ancient pathway that runs across the Somerset Levels – built in the early Bronze Age.  It consisted of posts of timber pushed into the soft peaty earth above the water with horizontal boards of split timber fixed to them. It created a causeway about 3-4 ft above the water that enabled people to walk easily regardless of the water level.

The timbers, which were embedded into the peat, which is anaerobic, didn’t rot and so the nearly 4,000 year old relics were discovered in the 1970s and at the time were considered the oldest timber trackway in Northern Europe. Nick has contemplated trying to incorporate the sweet track into the Levels display in the Garden as well.

“I would like to find out more about what the timber species were,” said Nick, “and maybe have those species growing in our display, perhaps with a sculptural representation of the sweet track.”

I look forward to seeing the display progress over the next year as the staff and volunteers bring the Somerset Levels to life here in the Botanic Garden.

Thursday, 19 September 2013

Bee and Pollination Festival Was Buzzing

Standing in the marquee at the Bee and Pollination Festival felt as close to being in a hive as one could imagine as it was absolutely buzzing with activity! As I weaved my way between the stalls I caught little pieces of conversations going on –“...beekeeping is not easy...first thing you need to do is take a course...”, “...which shutter speed should you use if you’re trying to get the wings of a bee in flight...” and “...have you heard of colony collapse disorder...” . My 5-year old was busy making a giant paper bee, while my husband spoke to the folks at the allotment display and I was admittedly taste testing some of the amazing local varieties of honey. There was something for everyone.

The University of Bristol Botanic Garden hosted the 4th annual Bee and Pollination Festival on the 7th and 8th of September, and as usual, people came out by the hundreds to celebrate bees and other pollinators that perform an essential ecosystem service. We do love our bees!

Nawbash helps a young bee enthusiast spot the queen.

Becoming a beekeeper

I happened to be looking at the display frame set up by the Bristol Beekeepers Association when a gentleman sidled up to Sue Jones, one of the beekeepers on hand to chat with the public, to ask about how one gets into beekeeping.

Sue quickly lays it on the line for him by saying “beekeeping is not easy”, but she quickly adds that some courses and hands-on experience are the first steps one needs to take to get into beekeeping. She’s not trying to discourage anyone from beekeeping, she, like anyone who has kept bees, knows that it is not something you enter into lightly.

Morgan (left) and Zippy (right) making a giant paper bee.
Nawbash Mohammed is another beekeeper on hand and so I begin to speak with her about being a beekeeper. The Bristol Beekeepers Association runs beginner beekeeping courses during the winter to cover the theory about beekeeping. The courses run over three Saturdays. Then, over the spring and summer, the Association offers practical education to cover all the hands-on aspects of beekeeping from opening a hive to handling the frames.

Nawbash has been a beekeeper since 1997, first in Iraq and then when she moved to Bristol in 2011. I ask her about beekeeping in Iraq and how it differs from keeping bees here in the UK. “The principles are all the same,” she says, “but it’s just very different weather and the honey has a very different taste”.  Nawbash describes for me the extremely unique taste of a premium honey in Iraq, made from the nectar collected from mountain flowers. I have to admit to her that this serene image of bees moving from flower to flower in mountain meadows is not the image that comes to mind when I think of Iraq – but I suppose it is the evening news that I have to thank for that. She admits there were additional challenges associated with being in a country fraught with war and political strife, but for the most part the challenges were the same facing beekeepers around the world – disease, mite infestation and colony collapse disorder.
Some of the honey on display and for sale at the festival.

Feeling thoroughly enlightened, I head over to buy a jar of Henleaze honey as I live in the neighbouring community – can’t get more local than that! “That’s my honey!” Nawbash laughs as she sees the jar I pick! Local, and I've met the beekeeper...brilliant!

The full experience

After speaking with Nawbash, I found my son and husband floating about the delicious cakes on display at the Bramble Farm table. Bramble Farm is a small landshare farm in Bristol. They keep sheep, pigs and turkeys and grow lots of veg, most of which goes to support the families that share in the upkeep in the farm, but any extra is sold at events such as this.

At the foot of the table lies a basket of some of the largest courgettes I’ve ever seen! However, it is some decadent chocolate cake that has caught the attention of my family! A little hint of fresh mint in the chocolate – delicious!
The apple press that kids took turns operating.

I stop briefly to look at the schedule of activities for the day as I don’t want to miss the demonstration hive talk. In doing so, I start to chat to a woman who is one of nearly one hundred volunteers that are there helping make the weekend’s events run smoothly. Jen Ellington is a committee member of Friends of the Garden as well as one of the Welcome Lodge Volunteers. She’s also opening up her garden next month as part of the Friends’ Open Gardens Programme - each year the Friends open their gardens, large or small, to raise funds for the Botanic Garden. Last year, Jen’s Gardyn raised over £400. Not bad considering her garden is only 15’ x 31’! However, don’t judge the garden by its size as it sounds as though there is plenty to see in this space. “We can’t go out anymore,” said Jen, “so we’re going up – I’m claiming my airspace!”  Within two minutes of listening to Jen’s description of her little garden haven, I'm hooked - so stay tuned to hear more as I will definitely be attending the open garden! The tour is Sunday, 6th October from 2-5pm and you don't have to be a Friend of the Garden to attend. The address is 4 Wroxham Drive, Little Stoke.
People gather around the demonstration hive.

Next we join the crowd outside the tent that is watching some children work a small apple press to make fresh apple juice. My son obviously has to have a go...after all, we need to wash down the chocolate cake!

We quickly make our way over to the display hive where the beekeeper is taking apart the hive to show the crowd the combs and what it’s like to work a hive.  As the smoke from his smoker rises up through the crowd, the beekeeper explains that “everything runs on pheromones in the hive. As soon as I open the hive, alarm pheromones will be released saying there’s an intruder. The smoke masks those pheromones. So you don’t ever let your smoker go out” - sage advice to any budding beekeepers in the audience.

Always something new to see

Ethel standing proud in a temporary position for the festival.
Of course, we can’t leave without touring the rest of the garden and I must say that the warm days of summer have made things all rather lush.  As my son stares into the pond outside, looking at what seems to be hundreds of dragonfly larvae, I admire the grape vines laden with fruit.

I also notice that Ethel, the giant willow moa bird sculpture, is finished and is on display!

There is a potted orchard, which is new – apples, blueberries, pears, figs, olives, plums and other edible delights line one of the pathways – another reminder of why we should celebrate pollinators!

Down near the glasshouses, Writhlington School has an extraordinary orchid display and inside the glasshouses the lotus plants are in bloom.

A pollinator at work in the garden.

I've said it before, but there really is always something new to see in the garden with every season. This weekend marked my second Bee and Pollination Festival and the anniversary of this blog. Having written the blog for the Garden for a year now, I also get to have some insight into some of the plans for the garden and new displays that are on the horizon. I have to say that I have been impressed to no end at how quickly things seem to turn from idea to reality in this garden. Of course, the staff and volunteers that are there every day doing the grunt work behind it all, may feel differently, but for someone who is there every few weeks, things seem to move at an incredible pace. It’s been a wonderful year and I look forward to sharing more about the people, plants, events and research that goes on in this beautiful garden.


Wednesday, 14 August 2013

RHS Courses: Getting practical in the garden

It’s Saturday morning at 9:30 and as I walk into the classroom there are fifteen small plates filled with different types of seeds lined up around a table. Along one of the walls, flowering plants are lined up as well. I recognise a few of the flowering plants but even then I wouldn't know the Latin names and I recognise even fewer of the seeds. I’m incredibly glad that I’m not taking the test.

I've come to sit in on the RHS Level 3 course ‘Certificate in Practical Horticulture’ that is currently running at the Botanic Garden. The course has been running every Saturday from 10am until 4:30pm since the 18th of May and it will continue until the end of August.

The course is taught by a number of tutors who teach for a block of seven weeks or so and it covers core units that include collecting and testing soil samples, collecting, preparing and propagating from seed, and identifying a range of common garden plants, diseases and disorders. The course is a balance of theory and practical and so students get to practice all the skills they learn in the classroom. Today, the students will be doing some seed and plant identification and then will be going outside to do some pruning.

Life experience brings added value to RHS courses

The teacher today is Chrissy Ching, a freelance horticulturalist who has been teaching RHS courses for over six years. When Chrissy isn’t teaching and running her business, she’s also being a student herself. She’s an MSc student at the University of Bath in Conservation of Historic Gardens and Cultural Landscapes, so she’s sympathetic to the demands on adult students.

No pictures of the RHS course, but I made a quick visit to
the glasshouse to see the lotus in bloom...beautiful!
Chrissy’s first involvement with RHS courses was as a student. She was an accountant when she first started taking RHS courses. “I thought I was doing it for interest originally,” said Chrissy. However, it eventually led to a complete career change.  Many of the students taking the RHS courses are also career changers and so this added dimension of life experience that Chrissy brings to the course is added value for many of the students.

But, it’s not only Chrissy that brings life experience to the course. The students themselves come from diverse backgrounds, whether in horticulture or not, and add to the learning experience also.

“I think the students learn as much from each other as they do from me,” said Chrissy.

Teaching RHS courses at the Botanic Garden

This is Chrissy’s first time teaching an RHS course here at the University of Bristol Botanic Garden though she has taught classes a the Birmingham Botanical Gardens and numerous college and city gardens. She sees this as a wonderful opportunity for the students.

“This is a living, breathing garden with a rich diversity of plants,” said Chrissy. “This gives the students a great way to study plants and especially taxonomy.”

Of course, she also points out that because the Garden is open to the public, it also has to look attractive. Therefore, it isn’t always ideal to have unskilled students practicing horticultural skills such as pruning. Luckily, Chrissy is there to help guide the process.


Motivated by tests and inspired by previous generations

As I’m there early, I take the opportunity to speak to some of the students before the class starts. Emma is the first student to arrive. She’s a young woman with a background in graphic design. She decided to take the course for interest as she secured an allotment about six months ago and wanted to learn more about gardening. She also thought it might provide some accreditation should she wish to shift careers, ideally combining her background in graphic design with a love of gardening to eventually get into garden design. 

This is the first RHS course Emma has taken. She was allowed to enter level 3 due to her academic background, however she admits that it’s been quite demanding at times.

“I wanted to take the course as I knew the challenge of tests would motivate me and stimulate my mind,” said Emma, “and it has. There’s been more theory to the course than I thought there would be and learning all the Latin names has definitely been tricky.”

Emma was inspired to take the RHS courses by her granddad who also did RHS courses and made a career in horticulture.

Enriching an existing career 

I slide over to talk to Darren as I’ve asked Nick, the curator of the Botanic Garden, to point out someone who’s here that works in the industry.  Darren is originally from Perth, Australia and has been in the UK for around nine years. For the past nine months he’s been working for a landscape gardening company and prior to that he worked for a gardening centre.

This is Darren’s 3rd RHS course and he started taking them because he was getting lots of questions from customers at work and he wanted to have the right answers. He’s here to enrich and further his existing career. That being said, so far, Darren has footed the bill for the courses himself, not to mention the significant time commitment that’s required.

However, for Darren, the courses are well worth it. He’s been impressed by the enthusiasm and wealth of knowledge from the tutors as well as the other participants in the class.

“It’s good to have a group of people who are like-minded,” he said, “to talk about the things that you’re interested in.”

Mimosa is also in bloom in the glasshouse
right now - they're like a little fireworks display!

Well-worth the commitment

Unfortunately I’m forced to leave the course less than an hour in. I have my five year old with me as it’s school holidays and his patience for horticulture is fairly minimal. However, what strikes me most as we jump on our bikes to spend the rest of this beautiful Saturday seeking out Gromit statues around the city, is the commitment these students have.

Most of these people have jobs, yet for nearly four months they have committed one day of their weekend to this course. Whether motivated by improved career options or by an interest in gardening, for them, this course is worth the commitment. For me as an outside observer, this speaks volumes.


If you are interested in learning more about the RHS courses taught at the Botanic Garden, please visit the website for more information.

Friday, 9 August 2013

There's plenty of room at the bee hotel

Andy gently pushes some moss out of the way to allow me to peer in. “See there,” he says, “they've moved some of this moss and built that wall – this is occupied”.  I’m staring into one of the rooms of the hotel trying not to invade the guests’ privacy, but also too curious to look away. The occupant seems to be out getting a meal or tucked away so as not to be seen by peeping eyes.

An occupied suite at the Botanic Garden's Bee Hotel.
We are standing in the wildlife area of the Botanic Garden, behind a city skyline of wooden planks. We are staring intently into what might at first glance look like a very artistically and precisely stacked woodpile.  However, this is indeed the Garden’s bee hotel - the sign above it even says so – and there are guests!

The Garden had quite a bit of bamboo left over from the construction of the Chinese herb garden, as well as other materials from some coppicing they had done, and what better way to use them than to create habitat to encourage native bees.


There are over 250 species of native bees and about 90% of these are solitary

Bee-opolis - a city skyline of wooden planks also serves as
potential habitat for solitary bees
Though we often think of hives humming with tens of thousands of bees, most bees in the UK actually lead a solitary lifestyle. This means that a female bee will find or make a burrow where she will rear her larvae on her own.

The nest type and habitat requirement of each species is a little different. The British Science Association created a very informative video in 2009 as part of their ‘Save Our Bees’ campaign, which talks about the habitat and nests for a variety of native bee species including leafcutter bees, masonry bees, tawny mining bees, cuckoo bumble bees  and carpenter bees.


There’s something for everyone at the bee hotel

The Bee Hotel
The bee hotel was constructed with many possible occupants in mind as well as their diverse habitat requirements.

On the ground floor of the hotel there is a section of large diameter plastic piping that has been sealed at both ends. Protruding out of the side of the pipe is a small piece of bamboo. This is ideal bumblebee habitat as the bamboo provides a narrow entrance but then opens up into the larger pipe.

There are 24 species of bumblebee in the UK, but only eight of these are common. Bumblebees build communal combs either underground or in long tussocky grass, with narrow entrances to discourage curious predators. This ground floor suite of the hotel fits the bill nicely.

As you move up from the ground floor you notice that a diversity of materials have been used including bricks and branches as well as bamboo.

Up closer to the penthouse suites it is mainly bamboo sections that have been stacked and the ends stuffed with moss. The one we are looking at has clear evidence that it has been occupied. Some of the moss has been moved aside and a mud wall has been constructed save for a small hole, about a ¼” in diameter, that is clearly the entrance.

The entire hotel is kept dry with a living roof with semperviren succulents and a skillfully woven willow ‘Bee Hotel’ sign to top it off.

Andy is clear that this is the Garden’s first foray into bee hotels, but this evidence that it’s being used within the first year of construction is encouraging. He is hoping that the diversity of habitats created within the hotel will attract lots of different insects, not just bees.


‘Hopefully it will encourage people to do something in their own garden’

There is global concern about the welfare of bee populations as loss of habitat and food sources, disease, and widespread use of toxic chemicals take their toll on these insects. The loss of bees has significant implications for food security as well as healthy ecosystems in general.

The staff at the Botanic Garden hope the Bee Hotel not only attracts insects, but also inspires visitors to the garden to construct habitats at home and help build resilience for our native pollinators.


Bee habitat doesn’t need to be complicated

Bamboo or branches cut into 10 inch lengths or so with 1/8-3/8” holes drilled 3-8 inches deep are ideal habitat for solitary bees. Bundle a group of these lengths together and hang them in a dry place and you’re done - simple. You can even use dried stems of raspberries, brambles and elder or other similarly sized hollow cane-like vegetation bundled together. 

The key, however, is that the material needs to be dry and it needs to stay dry. It is the wet rather than the cold of winter that can threaten these animals, so keeping the habitat dry is essential.

This is also a great project to do with children – from collecting the materials to maybe even some supervised drilling and then finally watching to see who moves in. I’m looking forward to building some habitats with my son...as well as watching the bee hotel at the Garden over the next year or so to see who has come to stay!


Photos of pollinators at work in the garden this week:







Monday, 5 August 2013

Plants that endure

by Helen Roberts

Whether perched upon a windblown cliff or nestled in a small crack deep within a canyon, some plants seem to overcome all odds of survival. These survivors, which are frequently rare, quite often grow in remote inhospitable environments, show true resilience and perseverance and are highly adapted to their specific habitats. You just have to admire them for their sheer tenacity.

However, some of these ‘bulldog’ plants aren’t the hardy-looking brutes one might expect of such survivors; sometimes they are delicate and very beautiful. Discoveries of plants such as these are occurring regularly with over 2,000 new plant species being found worldwide each year. Many are found in far flung areas of the globe, as well as on our very own doorstep here in Bristol.

A Malaysian beauty


The newly described Ridleyandra chuana with a
rare two flowers. Photo credit: L.S.L. Chua
A rare and endangered endemic plant found in the biologically diverse Pennisular Malaysia has recently been described. The beautiful plant is called Ridleyandra chuana and is only found in two small mountainous areas of forest.

The plant can be simply described as a perennial herb that is somewhat woody with a rosette of dark hairy leaves at its base. It has a long slender unbranched stem with very delicate and beautiful cone like flowers, which are white with dark maroon purple stripes.

This herb grows in very challenging habitats, such as moss covered granite rock emdedded in soil or moss covered granite boulders in extreme damp and shade on steep slopes.

The maroon/purple cone-like flower of
R. chuana. Photo credit: L.S.L. Chua.
The plant was initially discovered back in 1932 at Fraser’s Hill, Pahang, but only recently have enough data been collected to formally describe the plant. It is named after botanist and conservationist Lillian Swee Lian Chua who discovered another population whilst carrying out a biological inventory of summit flora on Gunung Ulu Kali, Pahang. Because of its limited numbers (only 130 individual plants are known to exist) it has been classed as Endangered under the IUCN criteria. Of the two locations of where it is found, one location is threatened.

"The population at Fraser's Hill falls within a Totally Protected Area and consists of about 30 plants that grow in an undisturbed site away from tourist trails and is too remote to be affected by development,” said Dr Ruth Kiew, author of the recent study describing this exquisite plant. “The other population consists of less than 100 plants at Gunung Ulu Kali, which is on private land in a hill resort that is severely threatened by road widening and associated landslips, by changes in microclimate due to edge effect as the forest becomes more and more fragmented and that is in danger of encroachment from future development. The chances of this latter population surviving is very slim. On the other hand, the rediscovery of the Fraser's Hill population after a hundred years illustrates the resilience of species to survive if the habitat remains undisturbed."

A beauty closer to home


Such rare and endangered plants that cling to life in the most inhospitable places are also found not too far from Bristol Botanic Gardens and are now being displayed at the Gardens as part of their ‘ex-situ’ conservation collections. The Avon Gorge, a Carboniferous limestone gorge cut out by the River Avon provides a sheltered microclimate of sun-baked niches for a wide variety of endemic species within ancient scrub and grassland communities. Many of these species are threatened by scrub invasion, introduced species and engineering works. Of these rare species, there are two endemic whitebeams, Sorbus bristoliensis and Sorbus wilmottiana that literally cling to life in the Gorge. 

They are being grown at the botanic gardens and also a number of newly discovered and described endemic whitebeams are currently being cultivated to add to the existing whitebeam collection. Wilmott’s Whitebeam (Sorbus wilmottiana) is listed by the charity Plantlife as one of our 10 most threatened woodland plants in the UK, which is why ex-situ populations are so important in helping to understand species and aid in the long term management and future development of the AvonGorge. The study and protection of rare plants is beneficial in the long run not only to the individual species, but also the plant communities to which they belong.