The University of Oxford Botanic Garden News - Harcourt Arboretum

Spring 201177The University of OxfordBotanicGardenNewsFor friends and supportersof the University of OxfordBotanic Garden andHarcourt ArboretumContents | A few words… | The healing power of plants | An inspiring harvestRecent developments | The ancient art of charcoal productionEducational activities | Garden and Arboretum eventsFriends’ news | Garden visits | Special events | The last word

2 Botanic Garden News | No. 77A few words...Timothy Walker has just celebrated the 25th anniversary ofhis joining the Garden staff as General Foreman. He has beenthe Horti Praefectus since 1988; the 16th person to occupythis position since 1642. In 2002 the post was renamed‘Director’ following current Universityemployment nomenclature but the Latinsynonym remains valid.byTimothyWalkeryears of work. The World’s land area is 600times that of the UK so it would take 169million years of work by one person tobring the World up to the UK standard froma standing start. This is the equivalent of4,225,000 careers, assuming 40 years ofwork per person.Once the World has been catalogued,how many people are required to maintainthe inventory? Using UK figures again, wehave 2,000 field botanists, hence the Worldneeds 1,200,000 in total.These are, of course, approximations, butthey do show that the task of monitoringbiodiversity is a huge one. These figures arefor plants only, which are among the bestunderstood groups (together with mammalsand birds). The task facing entomology ismuch bigger.The second problem is one of method.Do we survey the World country by countryIn the past 400 yearsapproximately 7,000 botanistshave contributed to ourcurrent understanding of theBritish flora - an accumulatedtotal of 281,700 years of work.If you were asked today to compile aninventory of the World’s land plantshow would you do it? The first problemwould be one of scale: the World is avery big place, approximately 57.5 millionsquare miles or 600 times the area of theUK, and carrying out a botanical surveyof it all would probably take more than alifetime. So how many lifetimes or peoplewould you need? It is reasonable to assumethat the flora of the UK is as well recordedas that of any country. If we knew how longit has taken to carry out that recording, wemight be able to calculate how long it wouldtake to record the rest of the World’s flora.Of course some countries already havecomprehensive records, but the calculationwould still be valid.The serious study of the Britishflora could be dated from 1836 with thefoundation of the Botanical Society ofLondon, now the Botanical Society ofthe British Isles (BSBI, www.bsbi.org.uk). However it goes back to before then,perhaps to 1660 when John Ray publishedhis Flora of Cambridgeshire. There aremany 17th century specimens in the OxfordUniversity Herbarium so we could say thatthe British flora has been studied for 400years, or the equivalent of 10 professionallifetimes.Now we need to know how manypeople have been working on botanisingBritain. The Select Committee on Science& Technology cannot answer that questionaccurately (see www.publications.parliament.uk/pa/ld200708/ldselect/ldsctech/162/16206.htm) and neither can I.However, there are currently approximately100 county recorders working for the BSBIin Britain. In Oxfordshire there are at leasttwenty first-class botanists in the field, soif this county is typical, there are currentlyapproximately 2,000 skilled botanists inBritain & Ireland, or one botanist for every30,000 citizens. (You may have noticedthat I have not attempted to differentiatebetween professional and amateurbotanists; it is clear that the amateurs greatlyout number the professionals.)If you extrapolate this back to 1600 whenthere were 4 million people living in Britain,then in the past 400 years approximately7,000 botanists have contributed to ourcurrent understanding of the British flora.That is an accumulated total of 281,700or do we organize botanists by botanicalfamily? In the former case we would endup with 195 national floras; in the latterwe would have 13,000 monographs forthe genera of flowering plants alone. Themajor advantages of country floras are thatcompiling them requires less travel and theyare more useful in the field. The advantageof monographs is that they take a globalview of species delimitation. In practice weneed both. In the Herbarium in Oxford thereare floras covering a wide variety of areas,ranging the whole of the USSR to Sheffieldand its surrounding region.If you do not already have a copy of yourcounty flora, I cannot recommend it highlyenough. The current flora of OxfordshireFilming for a television series on the History of Botany tookplace at the Arboretum and the Garden over the autumn andwinter. The series, which features Timothy Walker, will beshown on BBC4 in the spring.

at theUniversity of oxford Botanic GardenBotanic Garden News | No. 773The Healing Powerof Plants lecture seriesbyAlisonFosterRobert Morison (1620 -1683), Scottish botanistwho, with his contemporary John Ray,elucidated and developed the systematicclassification of plants.was published in 1998, the first for over 70years. It is a classic, a benchmark againstwhich all other floras can be judged. Itincludes all land plants from liverworts toflowering plants and there is a great deal ofbackground information on geology, historyand ecology.When it was first published it cost £45, butyou can now get a copy for the truly bargainprice of £20.50. If you would like one pleasecontact me on timothy.walker@obg.ox.ac.uk. £10 of the cost will go towardsan appeal for a new brush wood cutter forthe Bernwood Wildlife Group, the localvolunteer group which works on BBOWT(Berks, Berks & Oxon Wildlife Trust)reserves, mainly Whitecross Green Woodnear Horton cum Studley and RushbedsWood near Ludgershall.Dr Alison Foster worked as a chemistin the pharmaceutical industry foreight years until her passion for plantsgot the better of her. She has beenworking at the Botanic Garden sinceAugust 2008, initially as a traineehorticulturalist. She is currently oneof the Glasshouse horticultural teamand has planned the new medicinalplant collection at the Garden.On Monday evenings from October tomid-November last year, audiences in theDaubeny Lecture Theatre at the BotanicGarden were treated to a feast of plant science.The lecture series, entitled The HealingPower of Plants, brought together expertspeakers from institutions across the UK toimpress upon us the importance of plants(and soil microbes) in modern medicines.We began with an introduction to the newmedicinal plant area in the Garden byglasshouse horticulturalist Alison Foster. Sheexplained the stories behind the choice ofparticular plants, including how the oldesttree in the Garden – Bobart’s English YewTaxus baccata – is now of crucial importancein a modern treatment for breast and ovariancancer.“Elvis Lives!” painted on semi-solid agarmedium plates using spores of Streptomycescoelicolor (www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000510)The second speaker, Professor Sir DavidHopwood from the John Innes Centre,Norwich, dug deeper into the fascinatingworld of antibiotic-producing soil microbes.the Medicinal PlantcollectionWe heard about the introduction of the firstPlants and medicines have been intrinsicallylinked for centuries. even today, when soantibiotics and about recent advances in themuch modern research is behind every newpharmaceutical drug, plants play a vital rolein drug discovery and thus medicine. Whenfield, as well as how the pigments the that University of oxford theseBotanic Garden wasfounded as a physic garden we relied on plantsand other natural sources for medications. somany important drugs have been discovered inmicrobes create can be used by artists.plants since then and many others would nothave been developed without the inspirationprovided by plants. it is important for us toThe following week we learnt consider that how few a plants have actually beeninvestigated for their medicinal properties. it isestimated that only 10% of the plant species onearth have been studied in this manner. if thesespoonful of sugar does indeed help theplants are not conserved for the future then wemay never know what treasures lie within them.medicine go down. Robert Nash (PhytoquestLtd) explained the hidden world of plantderivediminosugars (sugar molecules inAlison Fosterwhich the ring oxygen atom is replaced by anitrogen atom). Robert has a long-standingcollaboration with Professor George Fleet(Department of Chemistry, Oxford) and wewere pleased to welcome George and hisgroup along to the talk.Professor Dianna Bowles from the Centrefor Novel Agricultural Products (CNAP),York, told us the amazing story of theArtemisia Project. Artemisia annua is thesource of artemisinin, the most importantanti-malarial therapy in use today. Despitebeing treatable, malaria is responsible foralmost 1 million deaths a year. The Project,which is funded by the Bill and MelindaGates Foundation (to the tune of over £26million), aims to create improved varietiesof Artemisia annua with higher artemisininyields and to deliver seeds at cost to growersin the countries most affected by malaria.The lecture series was brought to amemorable end by Professor MoniqueSimmonds, Deputy Keeper of the JodrellLaboratory and Head of the SustainableUses of Plants Group, Royal BotanicGardens, Kew. Monique gave us an overviewof the importance of medicinal plants assources of primary health care to peoplesaround the world, and of the issues causedby associated biodiversity loss.All the lectures were digitally recordedand are now available on-line as podcastsfrom the University of Oxford web site aswell as directly through iTunes:http://podcasts.ox.ac.uk/openspires.html, and click on Museums, Libraries andServices.the Medicinal Plant collection at the University of oxford Botanic Gardenthe Medicinal Plantcollectionat theUniversity of oxford Botanic GardenA new guide to theMedicinal PlantCollection at theBotanic Garden byDr Alison Foster,available from theBotanic Garden shopor via www.oushop.com/acatalog/Oxford_Botanic_Garden.html

4 Botanic Garden News | No. 77An inspiringharvestJim Penny came to the Botanic Garden as a trainee in 2009having previously worked at Yalding Organic Gardens inKent. When Ali Quantrell went on maternity leave in May2010 to have her twins, Jim took over the care of the Garden’svegetable beds and is now staying as part of the Hardy Collectionteam for at least another year.by JimPennyWhen we enter the astonishing world ofthe Botanic Garden we are prepared foranything. Giant amazonian water-lilies floaton limpid pools, carnivorous vegetationsnaps at passing flies, ancient trees leanand gesture over curiosities from everycorner of the globe. Then we see neat rowsof parsnips, carrots, cabbages. The presenceof vegetables in a botanic garden may seemodd or even impertinent. Their familiarityand ubiquity can make us look down onthem. In fact, as I hope to show, a plot ofgrowing vegetables touches issues at theheart of the botanic garden philosophy.Fruit and vegetables have had a place atthe Garden since its foundation when thefirst Superintendent, Jacob Bobart, grewand sold them to provide himself with anincome – his salary being unpaid for thefirst seven years of office. In the centuriesbetween then and now varieties of thecommon vegetables have transformedceaselessly, reflecting the changing tastesand needs of generations of growers andconsumers. Vegetables, with their shortreproductive cycles and intensive selectionby gardeners, illustrate wonderfully theprinciples of inheritance and selection.Mendel studied the patterns of inheritanceresulting from interbreeding nearly 30,000garden pea plants in the mid 19th century.Rediscovered, his work laid the foundationsfor modern genetics. Darwin’s evolutionaryinsights were informed not only by theexotic bird fauna of the Galapagos, but alsoby the hundreds of cross-pollinated cabbageIn 1887 allotments werestill seen as such animportant resource thata by-election in Spaldingwas won on a campaignspecifically demandingthat they be provided.seedlings that he raised in his garden atDown House in Kent.Our cultural and political history hasbeen touched many times by the ‘humble’vegetable. The discovery of sucrosecrystals in beetroot syrup in the 1740s ledto the development of sugar beet as analternative source of sugar to sugar cane.When, during the Napoleonic Wars, Britishblockades prevented French ships fromimporting cane sugar into Europe, theFrench responded by growing sugar beetat home. This production led to a collapsein the price of West Indies cane sugar andso contributed to economic pressure toabolish the slave trade. It is well known thatpotatoes played a huge and tragic role inIrish history – the ‘Great Hunger’ of 1845-9resulted in the deaths of perhaps a millionpeople and the displacement of 1.5 millionmore. A monoculture of one variety, withno resistance to potato blight, created theconditions for this catastrophe: a cleardemonstration of the importance of geneticdiversity in food crops, an issue which is stillrelevant today.Seventy years after the famine in Ireland,Kew Gardens ploughed up their lawnsto grow potatoes to ease food shortagescaused by the First World War. In August1918 thirty tons of potatoes were harvestedfrom these lawns. In the same periodthe ornamental beds facing Buckingham

Botanic Garden News | No. 775Photos: Lucinda Lewis-Crosbydesigned to show that food productioncan be undertaken at any scale and inany context, without using pesticides orinorganic fertilisers. We sow the majorityof our crops directly to reduce the need forpotting media and artificial heat. Our stakingmaterial is cut from coppiced hazel and birchstands at Harcourt Arboretum.Most importantly the plots produce asignificant harvest of vegetables withoutwhich all these ideas would make littlesense. We are lucky to be working with anOxford-based charity called Re-plenish, theOxford Food Bank (www.re-plenish.org)which redistributes vast amounts of foodfrom supermarkets – which would otherwisebe thrown away – to social projects inOxford. Every week throughout the growingseason a small, dedicated team of volunteerscomes to the Garden to harvest vegetablesand takes them to the kitchens of threePalace were turned over to the productionof vegetables. In modern Europe, wherefood production is hidden away from themajority if its consumers, vegetable growingis sometimes described as ‘fashionable’but historically it has been a necessity. Theloss of access to land for food productioncaused by the enclosure of commonsled to social upheaval, illustrated by theland occupations of Gerrard Winstanley’s‘Diggers’ and, two centuries later, thecreation of allotments to provide landlesslabourers with the opportunity, albeit ona limited scale, to grow their own food.In 1887 allotments were still seen as suchan important resource that a by-electionin Spalding was won on a campaignspecifically demanding that they beprovided.At the Botanic Garden we are beginningour third season of growing vegetableson an allotment scale with four beds eachmeasuring 18m x 5m. These are planted ina four-part rotation of brassicas; roots (notincluding potatoes) and onions; potatoes;and peas and beans. The plots becamesmaller this year to allow the planting ofapples and soft fruit on the most southerlyof last year’s plots. The scale of the bedsallows us to display a wide variety of thecommon vegetables. Trimmed, cleanedand packaged on a supermarket shelf,vegetables are familiar to most people.But to many, the plants that produce theseeveryday objects are as mysterious asthe exotics that generate coffee or cocoa.Visiting adults and schoolchildren alikemay be surprised and intrigued to seethe grasping tendrils of a pea plant, or aparsnip, covered in soil, with its crownof unwieldy foliage protruding from thetop. Plants grouped in their specific bedsfor the purpose of rotation illustrate theirlikenesses and differences. The brassicasall have similar requirements and thesame irresistible allure for the LargeWhite butterfly. At the same time theydemonstrate the extraordinary variabilitypossible within species: broccoli, cabbage,kale, kohl rabi, cauliflower and brusselssprouts are all forms of Brassica oleraceaand, here, this remarkable range can be seengrowing side by side.Modern food production has a hugeimpact on the resources and ecosystemsof the planet. In promoting the needfor conservation of plants and theirenvironments we are also encouraging amove towards a more sustainable approachto what we eat and how we grow it. Thevegetable plot at the Botanic Garden isThe vegetable plot at theBotanic Garden is designedto show that food productioncan be undertaken at anyscale and in any context,without using pesticides orinorganic fertilisers.particular projects: Donnington Doorstep, afree, drop-in family centre offering activitiesfor children of all ages, support and advicefor parents and carers and affordable lunchescooked on site every day; The Steppin’Stone Centre run by the Porch charity whichprovides support and a range of services forhomeless and insecurely housed people;and The Mill, run by the charity Mind, aproject for people with severe and enduringmental health problems which providesgroups and activities, a music studio and artspace, and good home-cooked meals.We are very grateful to the enthusiasticvolunteers from Re-plenish, particularly toRichard and Maureen Thorne and LucindaLewis-Crosby. We are using feedback fromthe projects to adapt our growing planseach year. ‘Harlequin’, a variety of carrotthat produces purple, orange and red rootshas been particularly popular with childrenat Donnington Doorstep. It will be grownagain this season with other varieties thathave performed very well on this site. Onthe other hand, we will temporarily abandonrunner beans which have proved to beless popular with chefs than the climbingFrench beans; and leeks, which sufferedan unexpected attack of leek moth lastsummer.This plot of vegetables at the BotanicGarden is providing a multitude of harvests:stories and histories; teaching; inspiration;and platefuls of fresh food.

6 Botanic Garden News | No. 77Recent developments at theUniversity of Oxford Botanic Gardenand Harcourt ArboretumbyTimothyWalkerThe Botanic GardenHardy CollectionThe first frost came in the middle of October2010 and the dahlias were no more. Theautumn was earlier than in the past fewyears, and short but quite spectacular;by the middle of November the Gardenwas looking very sad and ready to be putto bed. On the morning of Friday 17thDecember the sky over St Hilda’s Collegewas an ominous bright red, reminiscent ofJanuary 4th nearly 12 months earlier. It wasobserved that 36 hours after that Januarysunrise we were knee-deep in snow andsure enough by lunch time on December18th, 20cm of the wretched white stuff wascovering the Botanic Garden.In the subsequent week the airtemperature fell to –140C and the snowremained. The evergreen plants stickingup above it started to suffer. Cistus andcoronillas were looking miserable, exceptfor their lower 200mm. I assumed thatThe Garden under heavy snow,December 2010those plants covered in the ‘blanket’ werefine and this hypothesis was tested when itcame to harvesting vegetables from our ownplot for Christmas dinner. It was discoveredthat, sure enough, the soil was not frozenand the carrots and parsnips were easilypulled, in contrast to the year before whenan axe was required.The list of plants flowering on January1st was shorter than usual even thoughthe snow had melted. The Hamamelismollis, which is normally a sure bet to beflowering on Christmas day, did not reallystart its display of colour and scent untilthe middle of January. Despite the advicein many gardening books, you can growHamamelis on alkaline soils. The criticalfeature for successful cultivation appearsto be a moisture-retentive soil in the plant’sformative years before it has grown rootsdown to the water table. The Chimonanthuspraecox was also flowering well by themiddle of January along with Viburnum xbodnantense ‘Dawn’, Jasminum nudiflorum‘Seiboldianum’, and Lonicera x purpusii.In a strong cast of smelly plants thewinner must be Sarcococca confusa. This isa Top 10 plant if ever there was. The scentengulfs you like a blanket and is completelyout of proportion with the size of theflowers. Only the male flowers producenectar but it is not clear whether both sexesproduce scent. The other incongruousfeature of this species is the simultaneousflowering and fruiting; the black berries arein fabulous contrast to the white flowers.There must be a reason why the plant delaysChimonanthus praecoxthe development of its fruit for twelvemonths; possibly because the release ofseeds in the summer would coincide withdry conditions in its native China.There were eleven species ofSarcococca at the last count (in 1986)growing from Afghanistan to Chinaand into the Philippines. Their leavesall resemble those of Ruscus aculeatus(Butchers’ broom), especially the leavesof Sarcococca ruscifolia, though the leavesof the Ruscus are not leaves – they arephylloclades (from the Greek phyllo =leaves and klados = branch). So when isa leaf not a leaf? When there are flowersgrowing from it. In Ruscus the flowersappear to be growing from the centreof the leaves, which means that theleaves are in fact stems or branches thatresemble leaves. The leaves are presentbut in Ruscus aculeatus they are thesmall brown structures at the base of theflowers. The leaves of Ruscus hypoglossumare much more clearly visible.Hamamelis mollisRuscus aculeatusLeaves come in many different shapesand sizes and with many more functionsthan just photosynthesis. A new secondyearundergraduate practical class tookplace in the Garden in late October in whichthe students had to inspect sixty differentspecies and to comment on the leaves,their morphology and function. The resultof this work is that the students now knowthat a leaf is a structure at the base of a bud(subtending the bud to be precise) and thefunction is immaterial.

Botanic Garden News | No. 777The Botanic GardenGlasshousesA great advantage that botanic gardensoften have over other gardens is that theyhave glasshouses. Before Jacob Bobartretired in 1679 (he also died in this year) wehad a single ‘conservatory for evergreens’to grow the plants through the winter.Now we have a range of Glasshouses fromcompletely unheated to rather warm –minimum of 160C. During the cold spell thiswinter the boilers managed to give us the300C lift that they were designed to deliver.During these months (and coincidingwith teaching, as if it were planned) theGlasshouses are home to a good number offlowering plants and in particular monocotsand especially members of the familiesAraceae, Orchidaceae, Bromeliaceae,Asphodelaceae and Musaceae sensu lato.The Garden’s collection of bromeliads(members of the family Bromeliaceae) hasimproved during the past few years. This isan interesting, medium-sized family with2,650 species in 59 genera. Its distributionis almost exclusively tropical Americanexcept for one species which is found intropical West Africa, Pitcairnia feliciana.(The same distribution pattern is found inthe Cactaceae with just Rhipsalis bacciferagrowing outside the New World.) While theBromeliaceae is a well-defined family, thegroups within the family are much harderto see and building the evolutionary tree forthem is difficult.Many species are epiphytic, growing onthe bark and branches of trees. It is believedthat these epiphytes were pre-adapted tothis dry habitat by a number of xeromorphicadaptations. They often have a very toughleaf cuticle, with spines on the margin. Theyalso often have a modification of standardphotosynthesis known as Crassulacean acidmetabolism (CAM), first identified in plantssuch as Crassula ovata. CAM enables theThe Bromeliad Aechmea pinelianaCrassula ovataplant to fix carbon dioxide in the dark. Thissaves water because in order to fix CO 2 thestomata must be open to allow the ingressof the air. Unfortunately, permitting theingress of air also allows the egress of water.So if the stomata are open only duringthe cooler night-time then the plant willconserve precious water.Many members of the Bromeliaceaehave water tanks at the bases of their leaves,and these are such a permanent part ofthe ecosystem that other species, rangingfrom frogs to algae, have evolved to exploitthem as a habitat. It appears that thesetanks have more to do with nutrition thanwith the capture, storage and supply ofwater. In some species the volume of waterThe HarcourtArboretumAutumn arrived quickly at the end ofOctober and then made a run for it so thewhole season seemed to last just a fortnight.Since then the Arboretum has been grey andincreasingly wet.The Rycote sheep have been happilygrazing Pylon Meadow and Palmer’s Leys.The final third of the meadow in the latterwas successfully sowed in September 2010and when the snow melted there was a greenlayer of seedlings covering the soil. It appearsthat the germination from an autumn sowingis much more botanically uniform than froma spring sowing. The middle third of themeadow was sown in spring 2010 becausethe soil was too wet for sowing the previousautumn; there is an almost complete absenceof grasses but there are a large number ofEpilobium seedlings that have not beenfound elsewhere in Palmer’s Leys.The autumn work at the Arboretumis quite different from that at the Garden.One of the most creative activities is hedgelaying.On November 20th John Savings rana one-day hedge-laying course. There arenumerous different styles of hedge-laying,many centred on particular counties andregions. John is an inspiring tutor and hispupils made a beautiful job of the mixednative species hedge on the north boundaryof Pylon Meadow.stored in one plant can be as much as 20litres and at least one, Catopsis berteroana,secretes enzymes into the water to digestdead organic matter. Economically theBromeliads are important as tropicalbedding (6,000 cultivated varieties,especially Guzmania) and upholsterystuffing (the bizarre air plant Tillandsiausneoides, Spanish moss, found throughoutthe Glasshouses) but most importantly asthe supplier of pineapples.The bromeliads are spread throughoutthe Glasshouses with only one, Fasciculariapitcairnifolia, hardy in Oxford. In the sameway there is one species of Aloe that ishardy, Aloe striatula, while the rest needsome protection. There are 446 species ofAloe and many thrive and flower well inthe Arid House including the famous Aloevera. This is a ‘herbal remedy’ that is onthe cusp of being accepted by the clinicalcommunity. In Africa many species of Aloeare used for their healing properties. Theyare mentioned in Babylonian texts so theyhave been used in the Mediterranean regionfor several millennia. Extract of Aloe veracontains the antibiotic barbaloin which inthe juice of Aloe vera penetrates the skinfour times faster and seven times deeperthan in water. The juice also contains all theessential amino acids and twelve vitamins.Hedge-laying at the arboretumWinter is the traditional time for treesurgery and part of the work for this winteris the removal of five sycamores on theedge of the Acer Glade. These trees aredangerous and if they fell would land acrossthe all-weather path running along thecentre of the glade. In addition to removingdangerous trees and making others safe thereis tree planting. The oaks are still failing toregenerate naturally in Bluebell Wood and soit has been decided that fifty new oaks alongwith fifty birch trees to act as nurses will beplanted in the centre of the wood. These willhave to be well protected from the wretcheddeer but also must be visible to the personflailing bracken in the winter. This meansthat visitors will be able to see the cages fromthe path during the bluebell flowering periodbut this is a small price to pay for a few yearswhile the trees become big enough to lookafter themselves.

8Botanic Garden News | No. 77The ancient art ofcharcoal productionat Harcourt Arboretumby MalcolmRutherfordMalcolm Rutherford is originally from New Zealand and is a trainee at theBotanic Garden. He studied botany at university and later worked in rarebird conservation in New Zealand with the Kakapo and various seabirds,and taught ecology at Fota Wildlife Park in Ireland.It is half past five on a Wednesday inDecember. The sky is clear and thetemperature is around minus four.Buses don’t run at this time of day so I’mwaiting to be picked up by Guy, an arborist atHarcourt Arboretum. He is delayed a little bysnow but soon arrives and we are on our wayto Nuneham Courtenay. The time has cometo create some charcoal.Charcoal production is an ancient craftwhich, through the centuries, has led tosignificant steps forward in civilization.Charcoal burns at a hotter temperaturethan wood so was used to smelt metal frommined ore. This was first carried out on alarge scale in the Bronze Age. Improvementsin the efficiency of burning charcoal allowedhotter temperatures to be reached so thatharder metals like iron and alloys such asbrass could be smelted.Metal working relied on charcoaluntil a process to turn coal into coke wasdeveloped in 1735; within 100 years charcoalproduction in Great Britain had declinedArborist Guy Horwood tends the charcoal kilnsignificantly, despite the developmentof new uses for charcoal as horticulturalgrowing media, filtration media and as amedicine. Production was at its lowest pointin the mid 1980s but there has now beenan increase with the recent renaissance inwoodland crafts.By the time we arrive at the charcoal kiln,Karl (the other arborist at the Arboretum)has already started a bonfire which isa welcome source of heat on this crispmorning. Once there is a glowing pile ofembers we start to shovel these into atrench we have dug around the base of thekiln. The kiln is a large drum about 6 feet indiameter with a slightly peaked lid and airvents around the base. The previous day westacked it with wood from a recently felledtree, leaving air channels in a star shapeon the bottom and a space up the middleto allow air and heat to circulate evenlythroughout the stack. Some of the woodsoon catches alight and a huge amount ofsteamy smoke starts to come out of the kilnMalcolm Rutherfordas water is driven out of the wood. The steamrising is mirrored by large flakes of snowwhich have started to fall.Charcoal is produced by heating organicmatter in a low-oxygen environment. Thisdrives off the water and other volatilecompounds leaving the carbon skeleton ofthe plant. If burning is too rapid then thewood will burn away leaving a kiln full of ash,and if it is too slow then dry, slightly charredwood is left. To find the right balance we haveto control the amount of air entering the kilnthroughout the day by putting the lid on thekiln and blocking up the gap around the base.There are six vents, three of which we turninto chimneys by adding tall pipes and threeof which we leave as air intakes. Over thenext ten hours we check the embers burningthroughout the base of the kiln, adjusting theairflow as necessary. Ideally we would staywith the kiln until the smoke changes fromwhite to blueish grey. Unfortunately we aren’tcamping on site so we have to leave beforethis occurs, when the sun has gone down andthe working day is over. We block up all thevents to stop any oxygen from entering thekiln; now we have to wait a few days to seethe outcome of the burn.The production of charcoal is one ofthe most damaging practices in the world,responsible for deforestation, poor publichealth and greenhouse gas emissions. Anestimated 40 million tons of charcoal areproduced worldwide each year, half of themin Africa. In approximately 70% of EastAfrican homes charcoal is the sole energysource because electricity and fossil fuelsare unavailable or too expensive. Charcoal isoften produced and burned very inefficiently,and smoke and carbon monoxide fromcooking on indoor charcoal, wood, and dungfires cause an estimated 400,000 deaths(mainly of women and children) in subSaharan Africa every year. There are currentlyinitiatives trying to address these problems

Botanic Garden News | No. 779It is essential that the wood doesn’t burn too quickly, nor too slowlybut they are only having a small impact onthis massive and complex issue.If charcoal is such an environmentalnightmare, why are we creating it at HarcourtArboretum? Two thirds of the 60,000 tonsof charcoal sold each year in the UK areused on barbecues. Just 8% is producedin the UK, with the remainder importedfrom Africa (75%), China (10%), Central andSouth America, South East Asia, and a smallamount from continental Europe. With thelack of environmental regulation in manyof these regions it is almost guaranteed thatthis imported charcoal is not produced aspart of a sustainable forest managementprogramme. While a small proportion ofcharcoal comes from coconut and sugarcane waste material, almost all the restcomes from unsustainable sources suchas rainforests and mangrove swamps.By providing locally-made charcoal theArboretum aims to decrease the demand forrainforest-based charcoal.The second reason for producing charcoalat the Arboretum is to maintain an importantpart of our heritage. Charcoal productionin the UK has a long history as part ofsustainable coppiced woodland management.Coppicing (cutting trees back to the base,causing new shoots) is carried out on a 7to 20 year rotation. This retains importantwildlife habitats and provides an annualsupply of materials for making hurdles,stakes, thatching spars and fencing material.Additional woody material can be added tothe kiln and turned into charcoal, creatingsome revenue and removing excess woodfrom the woodland. Historically, woodsmenworked and lived in temporary charcoalburners’ camps, and quite literally providedthe fuel for the development of industry inthis country for centuries. It is on this traditionthat the recent resurgence of interest incharcoal production is based.The following week, when the charcoalkiln at Nuneham Courtenay has cooled, the lidis taken off to reveal beautiful charcoal, whichyou can now buy from the Arboretum ticketoffice (01865 343501).While it is great to support sustainablelocal woodland management for yourcharcoal needs, the most important thing isthat ‘buying British’ means that you won’t becooking sausages on something that was oncepart of a rainforest. To be part of the solutionto the problems surrounding this industry,purchase your barbeque charcoal from us orfrom another local charcoal producer. If youare buying from elsewhere be sure it is BritishFSC certified charcoal. You could also write toStephen Green, Trade Minister, and suggestthat only FSC-certified charcoal be importedinto the UK.Botanic Garden productsnow for sale on-lineA selection of the garden-related products available in ourticket office shop, including tools, books, notecards andchildren’s gifts, are now availableto buy online through the Oxford University Shop:www.oushop.com/acatalog/Oxford_Botanic_Garden.html

Botanic Garden News | No. 7711Garden and Arboretum eventsTo book places please call the Garden Office (01865 286690) with your credit or debit card details orsend a cheque made payable to Oxford Botanic Garden to: Public Education Programme, University ofOxford Botanic Garden, Rose Lane, Oxford OX1 4AZ.Printmaking workshopat the GardenJane Peart and Janet LueckMon 11th to Wed 13th April 2011Last August we welcomedtwo printmaker-artistsJane Peart and JanetLueck to lead a threedayprinting workshopin the Garden. Jane hasuntil recently been thetechnician at the OxfordPrintmakers Workshopand Janet is an art teacherat Pangbourne College.The workshop wasa great success and theThe Trentham Estate:A ContemporaryRevivalMichael WalkerThursday 10th March 2011,8.00pmMichael Walker will talk aboutthe successful regenerationof Trentham Park, a garden ofgrand scale recreated with nogovernment or lottery funding.≠≠Tickets £10Students at last August’s printmakingworkshopteam will return to the Garden in April to run a another three-day‘discovery of printing’ course for complete beginners. Students willbe introduced to the processes of collagraph (constructing a printingplate from cardboard, paper, plastic bags, even sandpaper), drypoint(an image is incised onto a printing plate with a hard pointed ‘needle’)and chine-collé (printing onto delicate Japanese papers). Studentswill use the Botanic Garden for inspiration for the first two days,spending time sketching outdoors and in the Glasshouses. Prints andproofs will be created on a portable printing press and day 3 will bespent at the fully-equipped Printmakers’ Workshop in Cowley, wherestudents can concentrate on making more prints on the full size‘rochat’ presses. All materials and equipment will be supplied.The course costs £180. To book a place, or to get furtherinformation, please phone the Garden office on 01865 286690 oremail emma.williams@obg.ox.ac.uk.Lectures at the Said Business SchoolThe Icing on the CakeGraham GoughThursday 24th March 2011,8.00pmGraham Gough was introducedto gardening at a very earlyage, confronted by fuchsiasand ‘Superstar’ roses in hisMum’s flower borders andbeing weaned on huge ‘WebbsWonderful’ lettuce from hisDad’s vegetable plot. Todayhe runs Marchant’s HardyPlants. His love and knowledgeof plants, people and placesshines through in his talks andhe is not beyond being frankabout his likes and dislikes.≠≠Tickets £10Study morningsat the GardenCompostingPauline Pears from HDRASaturday 19th March 2011For those who have never gotto grips with composting, thosewho would like to get started,and those who would liketo learn more about makingcompost.This course will be taught byPauline Pears and will includechoosing the right methodfor you (from hot compostingto worm bins), what can andcan’t be composted, building avirtual compost heap and usingcompost.The content of this coursewill conform to the GardenOrganic Guidelines for OrganicGardening.≠≠Tickets £20Pruning OrnamentalShrubs withConfidence Part 1and Part IIBrian DavisPart I, Saturday 26th MarchPart II, Saturday 9th April 2011Join Brian Davis for this twopart course that will look atthe pruning of ornamentalshrubs both on a yearly routineprocess and as a renovationmethod.The course will includeboth theory and a practicaldemonstration. Participantswill need to sign up for bothdays.≠≠Tickets £40 for the twomorningsStudy day at theArboretumMaking PlantSupportsThursday 24th or Friday25th March 2011Artist Tom Hare will teachyou how to create interestingand unique plant supports forthe garden. By the end of thecourse you will have producedat least one plant supportand leave with the skills andknowledge to continue creatingon your own.≠≠Tickets £60Free familyfriendlyevents at theArboretum(no need to book)Tuesdays 12th & 19th April2011, 1-4pmSpringtime funCome and explore theArboretum this spring. Makeyour own bunny, sow somegrass for it to eat and take ithome with you!Amazing azaleasTuesday 31st May 2011, 1-4pmSee the dazzling colours of ourrhododendrons and azaleas,and join in collage and craftactivities.

12 Botanic Garden News | No. 77Friends’ newsOur twentieth anniversaryDo come and celebrate at our anniversaryparty on May 21st (see page 14)The Friends’ 20th anniversary is a time forreal celebration. We have continued to besuccessful in our purpose of giving supportboth to the Botanic Garden and, increasingly,to Harcourt Arboretum. We have also helpedto extend links with the local and widercommunities and to give much pleasure withmany garden visits and events.The Friends have helped in many ways:≠≠By giving income from subscriptions,legacies, and profits from visits andevents;One of the benches and urns by the Garden fountain paid for by the Friends, photo byRos Diamond.Current support for the GardenOur major funding commitments forthe coming year are to the new compostdemonstration area at the Garden betweenthe Walled Garden and Rose Lane and themuch-needed Arboretum car park. Work onthe latter will include an encircling drain,levelling, a porous surface and plantingmany trees and small copses. TimothyWalker expects it to be ‘the most beautifulcar park in England’.The Friends’ e-bulletin is published three times a year, in between thenewsletter, in early May, September and January. It can be found at www.fobg.org. If you are not currently receiving notifications when a new e-bulletin ispublished, but would like to do so, please contact secretary@fobg.org.≠≠≠≠By organising appeals (including forGlasshouses, the education endowmentfund, benches and urns around thefountain pool at the Garden, and forthe purchase of Palmer’s Leys at theArboretum);By giving practical help via our manyvolunteers.We are planning to do much more in thecoming years. The Garden has an ambitiousstrategy and we want to do our very best tohelp make it possible. It remains a top priorityto continue to increase our membership toprovide a growing subscription income.Our regular £55,000 contribution to theGarden’s core funding has been allocated to:≠≠≠≠≠≠≠≠Improved facilities: re-soiling andturfing in the Medicinal and LowerGardenStaff training and a third of the salary ofone of the botanical horticulturalistsEquipment for the educationprogrammesPlant labellingbyRichardMayouCoffee mornings forFriends10.30am on the first Friday of each month inthe Garden’s Conservatory.After coffee a member of the Garden staff leadsa tour of the Garden:≠≠≠≠Fridays 4th March, 1st April, 6th May,3rd June, 1st JulyNo charge and no booking requiredSunday plant toursDirector Timothy Walker will highlight theplants that are looking good in the Gardenat the moment. A plant list will be provided.10.00am until 11.30am:≠≠Sundays 20th March, 12th June,11th September, 13th November≠≠Friends £2.00, guests £6.00(includes entry to the Garden)≠≠No booking required, just turn up.Leslie CowanLeslie Cowan, a founder of the Friends’Council and Membership Secretary for most ofour twenty years, died in October just beforeour last newsletter went to press. His businessexperience, deep understanding of IT and hisremarkable energy were fundamental to thegrowth and success of the Friends. He andhis wife Doreen, who became our Treasurer,devoted many hours each week to theFriends and were responsible for managingall the demanding membership and financialprocesses. Leslie was an exceptional personwho also worked hard for the Christian ScienceChurch, his village of Southmoor and forseveral other local charities. He was also a keenorganist and noted composer of organ music.Few people have done as much for their localcommunities and even fewer have done it sounobtrusively and so modestly.Friends’ seedcollectionWe have a limited number of packetsof seeds to give away. Each packetcontains a mixture of annuals andbiennials, collected from the BotanicGarden. To receive your free seeds,please send an SAE (at least postcardsized)to: Friends’ Seed Collection,Oxford Botanic Garden,Rose Lane, Oxford OX1 4AZ.

Botanic Garden News | No. 7713Summergarden visitsby Jane Annett, Harriet Brethertonand Pauline CoombesWe start the season with a coach trip to Malvern Show as many peoplehave requested this visit. We plan to do more coach trips as the cost ofpetrol continues to soar. Please book early as the visits fill very quicklyand tickets are allocated in the order that applications are received.Visits must be booked on the enclosed booking form. For enquiries,please phone the Garden office on 01865 286690, or e-mail the Friends’Administrator on secretary@fobg.org.Coach trip toRHS Malvern ShowSaturday 14th MayLeaving from Water Eaton Park andRide, Oxford, at 8.00amExquisite show gardens and bordersincluding the spectacular RHS FloralMarquee with displays from over 100nurseries. There will be stunning ‘Atom’themed gardens from the Chris BeardshawMentoring Scholarship, and hundreds ofexcellent show stands.≠≠≠≠Tickets £35, guests £38 [includes coachfare and £14.50 entrance fee]Maximum 53 peopleThrougham CourtFriday 20th May, 2.30pmThrougham Court, Througham GL6 7H6By kind permission of Dr C Facer HoffmanThis house and garden are Jacobean inorigin. The 3-acre garden is an amalgam ofthe work of 1930s architect Norman Jewsonand contemporary areas added in the lastten years. These are inspired by science andinclude Fibonacci’s walk, a cosmic evolutiongarden, and a Chiral terrace. The garden wasreviewed in the RHS magazine two years agoand many Friends asked if we could visit. DrFacer Hoffman will take us around herself.Tea is included.≠≠Tickets £15, guests £17.50≠≠Maximum 50 peopleBlewbury ManorThursday 2nd June, 2.00pmBlewbury Manor, Blewbury OX11 9QJBy kind permission of Mr & Mrs M R BlytheA part 17th century manor house (not open)with moat set in a delightful garden of aboutten acres. The garden includes a parterre,herbaceous and mixed borders, pergola,decorative vegetable and herb garden,stream planting, lake and a woodlandarea. The visit will be guided by the HeadGardener, Richard Roslyn, and includes teaand cake.≠≠Tickets £10, guests £12.50≠≠Maximum 50 peopleDouble visit to Woodchippingsand Spring Hill HouseSaturday 11th June11.00am Woodchippings, Juniper Hill,near Brackley NN13 5RHBy kind permission of Valerie Bexley and Richard BashfordMany of us have visited this small gardenin spring when it is packed with marveloustreasures. It is equally amazing in summer,with many interesting herbaceous plants.2.30pm Spring Hill House, Hethe,near Bicester, OX6 9ESBy kind permission of Mrs Penny JacobyThis 2-acre garden was started from a field16 years ago and has since undergone anamazing transformation. There are lovelyclimbing roses, mixed borders leading downto ponds and a stream. The owner is a plantspecialist so there are many interestingtreasures. Tea and home made biscuitsincluded.≠≠Tickets £15, guests £17.50≠≠Maximum 50 peopleDouble visit to Mill Deneand the Old VicarageSaturday 25th June11.00am Mill Dene Garden,School Lane, Blockley,Moreton-in-the Marsh GL56 9HUBy kind permission of Barry and Wendy DareThis lovely Cotswold garden will be at itsbest in June. The Rose Walk should bein bloom as should numerous other rosespecies, whose colours have been especiallychosen to compliment the under plantingof the borders. The garden has manyinteresting features including a Herb Gardenwhich offers opportunities to scratch ‘n sniff;some are aphrodisiacs, so beware!2.30pm The Old Vicarage, Bledington,Chipping Norton OX7 6UXBy kind permission of Sue and Tony WindsorOne and a half acre garden around a lateGeorgian vicarage. Borders and beds filledwith hardy perennials, shrubs and trees.Informal rose garden with over 300 DavidAustin roses. Small pond and vegetablepatch.≠≠Tickets £15.50; guests £17.50≠≠Maximum 50 peopleRoald Dahl’s GardenThursday 7th July, 2.30pmGypsy House, near Great MissendonHP16 0BPBy kind permission of Mrs DahlA rare chance to see the garden of RoaldDahl in aid of his children’s charity. Hewrote his famous stories in the caravan andthe beautifully landscaped gardens. Thegarden has many levels with steps makingit unsuitable for wheelchairs or for peoplewho have difficulty walking. Tea is included;please bring an umbrella if the weather iswet as there is little cover.≠≠Tickets £15, guests £17.50≠≠Maximum 50 peopleEythrope Walled Garden,WaddesdonTuesday 19th July, 6.30pmEythrope Walled Garden,Waddesdon Estate, HP18 OHSBy kind permission of Lord and Lady RothschildSue Dickenson, the Head Gardener, andJonathon Cooke will give us a guided tourof these beautiful, ornamental, kitchengardens. The gardens provide flowers, fruitand vegetables for the family throughoutthe year. Wine will be served after the tour.≠≠Tickets £15, guests £17.50≠≠Maximum 50 people≠≠Please provide your car registrationand mobile phone number on thebooking form.The Bobarts groupThe Bobarts group was set up six yearsago to provide extra financial support tothe Garden and so far we have raised anextra £46,000. Do please consider joiningthis patron group to give extra financialsupport to the Garden whilst enjoyinga special programme of exclusive smallgroup visits to private gardens. Details ofthe gardens we will visit this year are at:www.botanic-garden.ox.ac.uk/friends/obg-friends-bobart.html. We would bedelighted if you would join us; to do soplease contact the Friends’ AdministratorLiz Woolley on 01865 286690, orsecretary@fobg.org.

14 Botanic Garden News | No. 77Special eventsThe Friends’ special events programmeis growing all the time and is increasinglypopular. Last year we had a new,very successful, Christmas event inthe magically-lit Walled Garden andGlasshouses. Now we are busy planningfor May morning and our anniversaryparty. This means that there will be nojazz or soul concert at the Arboretum thissummer.If you would like to join the active andsociable group which organises and helpswith events, please contact our specialevents and volunteer co-ordinator MaryIsaac on maryisaac606@hotmail.comTickets for the following special eventsmust be booked on the enclosed bookingforms. For enquiries, please phone theGarden office on 01865 286690, or e-mailthe Friends’ Administrator on secretary@fobg.org.May MorningMay 1st, 5.00amEnjoy May Morning in the magical setting ofthe Botanic Garden at dawn, with the bestview in Oxford of the choir on Magdalentower.≠≠≠≠≠≠Gates open 5am, entry via West Gate,Rose LaneNo admittance after 5.15am and noaccess via Magdalen BridgeMorris dancing, 5.15am-5.45am;Magdalen Choir sings on the tower at6.00 am; coffee and croissants from6.00am.≠≠Adult Friends £10, adult guests £12,children £5Haseley CourtGardeners’Question TimeJune 9th, 6.00pmHaseley Court, Little Haseley, Nr ThameThis famous garden was designed originallyby Nancy Lancaster and is regarded as oneof the great gardens of England. It has sincebeen beautifully maintained by the presentowners Fiona and Desmond Heyward. Thegarden is not normally open to the public.Panel:Chairman: Timothy Walker, Director ofUniversity of Oxford Botanic Garden.Chris and Toby Marchant, Orchard DeneNursery, suppliers to many gold medalwinners at Chelsea.Val Bourne, garden correspondent of theDaily Telegraph and the Oxford Times.Matt Biggs, TV and radio broadcaster andauthor of many garden books.Jane Owen, garden historian and author.≠≠≠≠6.00pm reception, glass of wineand a walk around the garden7.00pm Gardeners’ Question Time≠≠Friends £12, guests £15New Chamber OperaJuly 13th, 6.30pmWarden’s garden and cloisters,New College, OxfordJoin us for a glass of sparkling wine in thecloisters, followed by a performance ofFalstaff by Antonio Salieri in the Warden’sprivate garden (or in the chapel if wet). Aftera couple of years of lesser-known operas bylesser-known composers (all neverthelesshighly enjoyable), this year New ChamberOpera will be putting on a familiar opera bya well-known composer, though not in afamiliar combination!This is a work which has been unfairlyneglected until recently and some say that,even compared to Verdi, Salieri’s opera iswitty, imaginative and contains music ofthe highest order. It includes the wonderfullaughter trio, the truly unique Bardolph’ssleep aria and inventions such as MistressFord pretending to be German to charmFalstaff. This should prove to be a real treat.Bring a picnic for the 75-minute intervalwhen tables are set out around the cloisters.≠≠5.00pm pre-performance talk≠≠6.30pm opera performance≠≠Talk tickets £2.50≠≠Opera tickets £40.00Professor Richard Mayou and the Directors of the Friends of Oxford Botanic Gardenhave pleasure in inviting Friends toThe Friends of Oxford Botanic GardenTwentieth Anniversary CelebrationsHarcourt Arboretum, Nuneham CourtenaySaturday 21st May 2011, 5–7pmAddress by Lord Patten, Chancellor of the University of Oxfordand President of the FriendsRaffle draw, live music, sparkling wine, canapésAzaleas and rhododendrons should be in flowerTwentiethanniversary raffleWe are enclosing tickets for our rafflewith this newsletter and hope you willbe willing to support our fundraisingby buying them and/or selling them tofriends, family or colleagues. The draw willtake place at the twentieth anniversaryparty on May 21st at Harcourt Arboretum.If you would like more tickets pleasecontact the Friends’ AdministratorLiz Woolley on 01865 286690, orsecretary@fobg.org.Friends only. No charge, but please book on the enclosed booking form.TICKETED ENTRANCE ONLY

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