Nurserymans Notes Nov 2024

The winter of 23/24 and spring was very wet which although it made all work on the ground more difficult was very welcome after the very severe droughts we suffered here in the preceding 2 years. 770 mm of rain was recorded here from mid October 2023 ( when the drought here ended) until mid June. Rainfall to date ( Late Nov 2024) has been 1180 mm.since mid Oct 2023 We had no late frosts here last spring ( and in fact not many frosty days during the winter)

Tree Diseases Severe disease of Ash trees caused by a fungus is now the norm across the country and it will probably not be long before a healthy looking Ash becomes a rarity, although I am told by Owen Johnson that in SE England there are a lot of trees still looking healthy after the disease has passed through. Larch disease, caused by another fungus ( now affecting both European and Japanese Larch) is prevalent across the whole of the UK and it seems that the only long term survivors will be odd trees and small groups. A tragedy for British forestry.( even worse for the Europeans if it gets to the Alps) Threats are on the horizon for other even more important forestry species and this is a great worry. Luckily Larch trees growing as single specimens, especially in open positions seem to escape the disease. Even Oak is threatened with diseases which have been around for some years but are becoming more prevalent. Box moth caterpillars have this year for the first time attacked almost all of our Box, it seems to me that it is no longer worth considering planting Box ( in most southern parts of the country) for any purpose since the caterpillars will effectively kill it, returning in future years to kill off any survivors. A disaster for gardens with box hedges and perhaps even more so for the few places in the UK where the Box grew wild. Killing the caterpillars with nematodes needs to be done every year at regular intervals if one wants Box to survive, so in most cases is impractical or not worthwhile. My view and that of many experts, is that we must diversify tree planting in the UK to lessen the risks to our woodlands and forests from disease wiping out another of our main species. Planting different genera and species to those normally planted and planting trees from more Southerly seed sources, probably better able to cope with the changing climate seems a most sensible course of action. Just a few possible thoughts are : Celtis, Gleditsia, Toona, Juglans nigra, Robinia, Sorbus (Cormus) domestica and non native species of oak such as Quercus pubescens and Q. canariensis, but of course there are very many others.

Grey squirrels ( originating from Canada) are a huge threat to the growth of future woodlands and forests. Nearly all the magnificent forests of Oak and Beech we enjoy so much today grew before the uncontrolled explosion of population of the greys ( they were very actively killed in huge numbers by the Forestry Commission and others until about the 1960s) Without much more active control there will be very few of such forests in the future. Many broadleaved tree species are effectively destroyed by Grey squirrels once they reach a height of about 3 metres, the repeated ring barking will result in large shrubs with broken and dying tops. So many opportunities seem to be missed about informing the general public about this massive threat ( Grey squirrel damage possibly costing about £30 million per annum in the U.K.) Often in TV programs and the Press the threat to our native red squirrels is given as the main reason for control of greys and whilst this is very important it is arguably less important than their habit of effectively destroying the trees of the future, which is often not mentioned. If the general public could be educated to regarded Greys as vandalistic tree rats ( as all foresters do) then a policy of complete eradication might become publicly acceptable. Mainland Europe is free of grey squirrels ( apart from a tiny area in Italy where strenuous efforts to eradicate them are underway) so our European neighbours are able to grow young trees like Oak, Beech and Maple without the grave risk of them being destroyed by grey squirrels. ( Native European squirrel species do not normally cause much damage to trees, certainly nothing like that caused by the grey tree rats.)
This spring from late May to early June 2024 the grey squirrels have caused exceptionally severe damage here , no doubt because most of the trees are growing particularly well with the moist soil conditions. ( Squirrels always select the most luxuriant growing trees to strip the bark from). I have just heard (14 June) from a very experienced tree planting friend of mine that he is shocked and dismayed that some Oaks 30 ft high very close to his house have had terrible squirrel damage this year, some with all the bark stripped from ground level to up high. This all happened a few days ago over a period of about 48 hours. I am quite certain there are going to be very many similar sad tales this season. At one of our woods Squirrels have effectively destroyed about ten thousand oak I planted there about 25 years ago. They started as soon as the trees reached about 3 metres high and then repeatedly damage them as they grow every few years, the result is stunted bushes, That wood is in mid Wales where the squirrel damage is always much worse than here, in that region there are very few tree species they don’t seriously damage. Squirrel damage to trees probably costs about £30 million pounds per annum ( a figure of the same order is associated with costs associated with TB control in cattle) the public I think hear a great deal more about the problems of TB in cattle than the devastating losses of trees caused by Grey squirrels. One should remember that the wonderful mature Beech and Oak woods which we enjoy today grew through the stage at which they were most vulnerable to grey squirrel damage ( 5- 30 years of age) when populations of grey squirrels was very much lower than today. ( from about the 1940s to the 1960s the Forestry commission has a very active and effective control strategy by trapping, poisoning and shooting) The UK squirrel accord (UKSA) is a body of about 40 organisations working together to try to eliminate the very serious threat squirrels pose to the continued growth of trees in the UK.

Living with Deer. The first deer ( Fallow, escapees from nearby Berkeley estate) were seen here about 35 years ago , since then numbers have increased enormously and appear to be still increasing. About 20 years ago we saw the first Muntjac deer and numbers of them have increased rapidly too . All trees we plant here have to be guarded against deer for between 5 and 15 years ( depending on the particular species palatability or attractiveness for scent marking/ antler rubbing) The deer will destroy virtually all species of small trees unless they are guarded. If bigger trees are planted they will often break the tops off and also effectively destroy them too by stripping the bark with their antlers . Some species are much more attractive to deer than others and species such as Apples, Holly, Walnuts , Laurel and Portugal laurel , Maples and all species of conifers can be killed even when the trunks are up to 3” in diameter. A few species such as Lime and Oak are rarely damaged when they reach that size. The woodlands in this area have suffered enormous damage from deer browsing, shrub species have almost disappeared and almost all new seedling trees are destroyed when very young.

There are very few tree and shrub species indeed that deer will not damage when young, one is Bay, Laurus nobilis ( also said to be unattractive to rabbits.) I have started using bay where in the past I would have used Holly or Portugal laurel or Box. Another possible evergreen hedge plant or shrub is Lonicera nitida and Lonicera pileata, these are not browsed by deer. Luma apiculata , the beautiful evergreen flowering shrub/tree also seems deer proof. Ruscus aculeateus Butchers broom, is not touched by deer. Even Yew can be badly damaged by deer, especially when young. Generally deer do not cause serious damage to most species planted in new hedges although they will often damage odd plants, particularly those on the end of lines. Guarding trees against deer 1.2 metre tree tubes are unfortunately not tall enough to protect trees from Fallow deer ( although they will just about protect them from Roe and will certainly protect against Muntjac.). 1.5 metre high tubes and other types of tall guards which will give better protection against Fallow deer are obtainable but are very expensive, require more expensive stakes and the use of such extra tall tubes can result in the trees inside becoming too drawn up and with floppy stems. Live hedging guarding technique is a method which can be used to protect some tree species eg Oak from destruction by deer. The Oak for example is planted surrounded by a minimum of 3, or better 4 or more Hawthorn plants planted 30cm away in a circle around the oak. When young they will all be browsed by deer but eventually the oak will grow out from the surrounding hawthorn bushes. This technique simulates what happens in nature but normally needs eventual subsequent removal of the thorn bushes. Complete fencing against deer is the best and most reliable method of guarding the area to be planted, but costs can be very high. It is usually more economical to use a double height fence of C8/80/15 standard stock fence than specific 6ft or higher deer fencing. The double height C/80 /15 fencing is also easier to erect and repair. I use circles of single height C8/80/15 fencing about 2 metres in diameter to protect individual trees from deer, this is simple and reasonably effective.

New ( for me) cordless Stihl power tools to make tree management easier. A few months ago I bought a Stihl mini pruning chainsaw (100mm bar) the GTA26, about £140 including 2 batteries. Although targeted at the modest garden DIY market I have found it a very good tool for pruning where branches are a bit too big for the largest professional Bahco loppers but too small or fiddly for a proper chainsaw. Considering the tiny batteries and its very lightweight if used with care it is a great addition to the tools used by professional tree growers. There is an option to buy an extension shaft for this to make it a mini pole saw but I don’t think this would be any good except in very small gardens for very light pruning. I have also very recently bought a Stihl Polesaw, HTA50 which uses their AK batteries, again aimed at the DIY market. This has much bigger batteries than the GTA26 and has a 10” bar About £440.00 including 2 batteries. I am amazed how long the battery lasts and how good the tool is, almost up to professional standard use. One battery would probably be quite sufficient for most users. I also use a professional Echo petrol pole saw with a 12” bar but this HTA50 is almost as good and much lighter to use and easier to transport. I use power pole saws a great deal and will in future be mostly using the new HTA50.( Stihl also make a professional model battery, cordless pole saw but that is much heavier and much more expensive). If used with care Im confident the HTA50 will be a trouble free tool. I have since bought the AK battery powered 60cm bar hedge trimmer, again excellent and almost as robust as my Stihl petrol powered ones. I have bought all my chainsaws by mail order over the past 20 years from Radmore and Tucker, a long established family firm of specialist arboricultural suppliers. These latest saws came from them. They are usually the cheapest and also provide excellent service. See www.radmoreandtucker.co.uk. Prices mentioned above include VAT.

Luminous footsteps in the forest. Below is a letter ( very slightly amended) I wrote to the editor of the Royal Forestry Society in October 2005. “A year ago while walking at night ( negligible moonlight) in a cleared Sitka spruce plantation in North Wales I was amazed to find I was leaving behind a trail of luminous footprints on the bare peaty soil (in fact each footprint was ‘marked’ by approx. 20 glowing spots). The phenomenon was only apparent in one small area a few metres long and the luminous points faded away after about 30 seconds but could be re-activated be treading on the spot again. The cause is apparently the disturbance caused by the footsteps giving a boost of oxygen to mycelial threads of a fungus. I have spoken to several experts and the phenomenon is rare or very rare and the fungus ( or just possibly bacteria?) has not been identified: I have found only one other reference to a very similar ( or probably the same) phenomenon, Page 33 in “The Nature of central Wales” by Dr. Fred Slater published in 1988. There is a good general account of bioluminescence in fungi in “Mushrooms and Toadstools” by J. Ramsbotton (Collins New Naturalist 1953) Luminous fungi associated with decaying wood is said to be relatively common ( normally seen associated with Honey fungus) although I wonder how many other foresters have seen this ) I have only once, very many years ago. When I revisited the site of the glowing footsteps a year later in October 2006, there was only one very small area which showed a few luminous points when activated by disturbance. I should be pleased to hear from anybody who has similar experience or knowledge of bioluminescence in woodlands and how frequently it is observed.” Geoff Locke. Dec 2005

I had no significant response from readers of the journal. I have since spoken to several experts and no one has been able to give me very significant further information. Internet searches have also drawn a blank. I have recently ( Dec 2023) been in correspondence with Dr Fred Slater and he has given me more very helpful information about his reference to glowing footprints. Also Prof Gareth Griffith ( Aberystwth) and Ray Woods have very recently given much helpful information. The phenomenon remains apparently very rarely documented and not fully understood ( the latter being the case with much of the Fungal world!) There is of course masses of information about bioluminescence on the internet but I have not found anything to answer all my questions. Wikipedia, which I think is excellent, has several entries about bioluminescence. Among the many references in one Wikipedia article is a paper by Vadim Viviani from Brazil, about 13 pages titled Terrestrial Biolumincence written in 2009. Bioluminescence is much more common among sea creatures ( particularly those in very deep sea) and organisms than on land and fresh water. There is consequently relatively little written about non marine bioluminescence.

Almost everyone with an interest in Fungi will have read the brilliant book: Entangled Life by Merlin Sheldrake published 2020 with deservedly high acclaim. One of the most interesting books I have read for several years.

Coast and Giant Redwoods, Anyone who has visited the nursery ( or even looked at our patch on Google earth) will have noticed that I have planted here many Giant Redwoods and a few Coast Redwoods. I planted the first of these about 45 years ago and both species of those early plantings are now very big trees. Most people seeing those early trees I planted here ( they are not in the tree nursery area) cannot believe they are only 45 years old. Giant redwood is one of the few conifer species which grow well on some of my wetter land which gets very wet in winter but drought stricken most summers. Giant Redwood is also one of the few conifers which in my experience is never damaged by squirrels. I am a great admirer and lover of both species and have planted several hundred in total on our own ground. I read everything I can about them ( there are plenty of good books and a few not so good)

The book by Richard Preston titled The Wild Trees, published 2008 is now out of print but is often available on Amazon. One of my favourite books of the last few years. It tells a great story of young mens and womens passion to climb and measure the tallest Coast Redwoods in California. Starting out as college students in the late 1980s these folk fell in love with the trees ( and in one case each other and spent their honeymoon night 300 ft up a redwood!). These two Americans Steve Sillett and Marie Antoine have become professors specialising in the Big Trees and the unique habitat in their canopies. They are now world authorities on the subject. Members of the International Dendrology Society will be able to read some of Prof Silletts writing on the subject. The book by Richard Preston titled The Wild Trees, published 2008 is now out of print but is often available on Amazon. One of my favourite books of the last few years. I have very recently heard of large a new ambitious novel carbon offsetting scheme involving the planting of many thousands of Giant Redwoods in new forests to be created ( the ones so far in the Abergavenny and Hereford areas) I generally have several reservations about carbon offsetting businesses, but this private enterprise scheme may be better than most , See WWW.THEGREATRESERVE. In any case it cannot be a bad thing to plant thousands more Giant Redwoods in the U.K.

For those who have read this far may be interested to know that the Tree Register of The British Isles (TROBI) has just started publishing an annual yearbook, this is a terrific improvement on the old style leaflet and makes it even more worth joining this organisation. The biggest data base of record breaking trees ( generally in terms of height and girth) of every species. Over a quarter of a million different trees logged of almost every species which will grow in the UK. The registrar of the society is Dr Owen Johnson MBE , he is in my opinion the foremost overall expert on UK trees. In 2015 he wrote “Arboretum- A history of the trees grown in Britain and Ireland”, published Whittet books, I think it is an excellent book, one of the very best , and a must have for any tree enthusiast . Available from Amazon at £30.00 ( 450+ pages of very readable, accurate information about the huge range of trees that can be grown in the UK.) The Amazon review ( not written by me) sums it up beautifully. Owens Johnsons field guide titled “ Collins Tree Guide” published 2004 is also packed with information and is I think the best and most up to date available. 450 pages at what I think is a bargain price. There is a less comprehensive version with the same title but most enthusiasts will prefer the full version. I had mistakenly imagined that the books were a rehash of the original title written by my late friend, Alan Mitchell, in fact the books contain lots of new material written with great style by Owen Johnson.

International Dendrology Society (IDS) Lime (Tilia) study day 28 June 2024 at Peasmarsh Place, Sussex. About 30 members of the society including myself and my wife attended this event held at Peasmarsh which houses one of the National Collections of Lime. The property is owned by The Viscount Devonport who is a great plantsman and especially interested in Limes, he has been on expeditions to the far east sometimes in the company of the late Professor Donald Pigott an international expert on Limes. The day was very well led by Dr Owen Johnson, author, tree recorder for TROBI and expert on all trees growing in the UK. Much reference was made to the definitive technical book on Limes written in 2012 by Professor Pigott, the culmination of a lifetimes study of Limes around the world. ( Lime trees and Basswoods. A biological monograph of the genus Tilia, Published Cambridge University Press. Available new from Amazon for about £130.00, nearly 400 pages of succinct botanical information well illustrated with pen and ink drawings) Some of the attendees were keenly interested and quite experts in Limes but many were just interested in the genus in general among other tree genera. We enjoyed seeing many of the limes in blossom. I regard the fragrance of most species of Lime as among the most beautiful of fragrances. Owen described the different characteristics of most of the approximately 23 species of lime which exist ( 4 from Europe; 17 from East Asia; and 2 from the American continent) and samples of foliage, some with flowers were passed round. Limes can be very confusing partly because the foliage can vary significantly within species. The existence of many sub-species further complicates matters. Even though I have been keenly interested in Limes I am sure I was not the only one who was more than a a bit puzzled by some of the specimens. Features which are used in determination of different species of limes are leaf shape, number of flowers in cluster and date of flowering, size and shape of flower bract, size and shape of seeds, texture of leaf and particularly whether the underside has microscopic hairs which often gives the underside a silvery appearance. In several species the hairs are forked at the top (stellate) and the number of arms in the fork can be a distinguishing feature, and bark structure, even considering all these factors it can still be very difficult to make a positive id of some species.( Even Owen Johnson had difficulty in a recent visit, identifying some of the limes growing here at Mount Pleasant arboretum.) We saw 2 areas of planting of Limes at Peasmarsh, one of which was chosen to try to match the conditions in which some of the Asiatic Limes grow for the Asiatic species planted there. Apart from the easy and healthy growth of Limes and the long flowering period if different species are planted, very importantly, they are one of the very few trees which are not damaged by grey squirrels. They grow very well on our heavy alkaline soil which gets very dry indeed most Summers. I have planted quite a few too on some of my more fertile free draining neutral to acid normally moist soil and they all grow very well there too. Too many people are put off limes by imagining that all will be aphid infested and that will cause the problems with their excreta ( Honey dew) causing the sticky mess so often experienced under the hybrid European Lime formerly often planted in cities. Most species of lime are rarely seriously attacked by aphids so honey dew is generally not a problem except with hybrid European Lime.

Among my favourite Limes are Tilia cordata, Tilia mongolica, Tilia chingiana, Tilia concinna ( this very rare lime growing at Kew ( Kew ref 69-16884) had been noticed independently by Dr Donald Pigott, and a couple of other Lime enthusiasts including myself. Donald researched its origin at Kew and was the first to give it its name, it really is a fabulous lime but endangered or possibly extinct in its native Asia). I propagated it with the permission of Kew many years ago and gave young plants to Donald and sold a few to other people Another favourite of mine is a clone of Tilia tuan, grafting material was given to me by Donald for propagation immediately he arrived back in the UK after an arduous trip back from a remote area of China where he collected propagation material of that and other Limes. This clone is quite similar to some clones of T. oliveri. I have mentioned that I particularly like Tilia chingiana, an interesting feature of the clone of that species I have here as well as having a very good shape and attractive silvery backed leaves, the really notable feature though is that the green leaves are held on the tree later than any other lime I have here, normally till very late November. ( The date of leaf drop relative to other species and cultivars can also be a helpful featyre when trying to identify Limes. Lastly as well as T. cordata Len Parvin ( with exceptionally small leaves and extra profuse flowers) I really like T. x Westonbirt Dainty Leaf, ( probably a hybrid between T. cordata and T. japonica) to which it is similar. This was given to me by John White, dendrologist, then working at Westonbirt. I named and propagated it and sold a few dozen about 20 years ago. I must not forget my admiration of many of the American limes some of which can have enormous leaves, especially on cut back trees. Mistletoe has colonised several different species of Lime here including Asiatic and American species. Members of the IDS will be able to read a full detailed ( and impartial!) report of the day in the new annual ( always superb) yearbook to be published in May 2025.

Rockhampton Arboretum I have decided that the collection of trees I have planted here on about 7 acres of our land over the last about 35-40 years can legitimately now be called an arboretum. My view is further reinforced by the recent visit of Owen Johnson in June 2024 ( Tree registrar of “Tree register of the British Isles). He spent several hours here measuring and recording the trees here and recorded many which interested him, including several which are County and a few are National champions. ( most of those he recorded as National champions are trees which I have discovered here and introduced to horticulture eg Carpinus betulus Rockhampton Red; Pterocarya stenoptera Fern Leaf ; Platanus orientalis Rockhampton Autumn Red; Tilia cordata x Westonbirt Dainty Leaf; Tilia cordata Len Parvin The collection includes only trees which will grow relatively well on the heavy alkaline soil we have here which is often waterlogged for much of the winter and is drought stricken most summers. Almost all species and cultivars of Tilia are present. There are a lot of different Parrotias. There are many Sorbus torminalis, several Plane species and cultivars, some interesting Corylus, a good collection of Acer campestre cultivars including a couple unique to here, A good collection of golden leaved cultivars of many tree species and numerous other broadleaved species. There are only a few different species of conifers since the ground here is unsuitable for most. There are a lot of Sequoiadendron giganteum which grow well here and some Sequoia sempervirens and cultivars thereof. There are a few rare and interesting Poplars and possibly the second biggest Pterocarya x rehderiana in Glos. We are in an area where mistletoe grows very well naturally and it grows here on many of the trees I have planted including several unusual hosts such as Black walnut and Hazel. There are a few hundred trees in the collection. The arboretum is not open to the public but I am considering opening one or two days a year in the future to raise money for charities.

Woodland Heritage is a charity which I support, its aims are generally to encourage better management of woodlands and forests to produce better quality timber and to support work in investigating tree diseases. There is great diversity among the members from Professional foresters and woodland managers to furniture makers and ever other sort of person who has a hobby or professional interest in trees. For a relatively modest membership fee one gets a very good yearbook, with many interesting articles and the opportunity to attend diverse, very interesting and well organised visits to all sorts of venues related to trees and timber use.

Geoff Locke. 30.11.24

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