Being the festive season with mistletoe decorations and mistletoe kisses, this strange plant seemed a suitable subject for a blog, so here are some facts, superstitions and folklore...

As a plant without obvious roots or sources of food, it was once thought entirely magical and credited with extraordinary powers - giving rise to its use in medicine and a rich history of folklore. In the Middle Ages it was thought to break the death-like trances of epileptics, dispel tumours, divine treasure, keep witches at bay, and protect the crop of the trees on which it grew. Its use in the treatment of epilpsy continued into the 17th century and, as recently as 1993, a sixty-six year old man told of how, as a boy, he was given mistletoe by a gypsy woman to treat his epileptic fits, and that he had had no seizures since. I have seen mistletoe most commonly on Limes and Apples, but also on Hawthorn, Poplar, Willow, Rowan and False Acacia. It will undoubtedly grow on many other species but Pliny refers to its rarity on Oak, making 'Oak Mistletoe' highly valued for its 'powers' - Oliver Rackham questions if it is ever found on ancient Oak.

Enough myth and folklore - now for something completely different - a few mistletoe facts:

Mistletoe is in the Order Santales which includes the valuable and scented Sandalwood tree. The Order contains many epiphytes, parasites and hemi-parasites - including the Sandalwood tree itself which, when young at least, taps into the roots of a variety of host trees. Foresters growing Sandalwood in plantations will often use Acacia to start them off. Mistletoe is termed a hemi-parasite because its green leaves manufacture sugars by photosynthesis and it draws only water and mineral nutrients from the host.

There are over seventy species of Mistletoe worldwide, the European Mistletoe being the only one native to Britain. It prefers a mild, humid climate and good numbers of suitable host trees and is particularly common in a wide circle of land around the Severn estuary, where the valleys are moist and there is a tradition of fruit growing.

Whilst host trees can often tolerate some uninvited mistletoe, it can also be harmful, certainly killing branches and even whole trees if the 'infection' is heavy enough. Trees 'pull' water up through millions of tiny vessels, the pulling force being exerted by the osmotic pressure within the leaves and transpiration (evaporation) of water through leaf pores. The force is considerable and the millions of threads of water are as taught as piano wire. They can snap - something that is called cavitation but that a plumber might call an air lock, or a surgeon an embolus - and cells relying on the water from those vessels will die. Mistletoe can increase the tendency to cavitation and sometimes the water supply can give out and the host is killed by desiccation.

A sailor's wife had chestnuts in her lap,
And mounched and mounched and mounched.
'Give me,' quoth I.
'Aroint thee, witch!'
the rump-fed ronyon cries.

from Macbeth

Seasons Greetings! The obvious choice for December's Tree of the Month was the Christmas Tree, but for me roast chestnuts are such an essential part of Christmas festivities that this month it simply had to be the Sweet or Spanish Chestnut. I first tasted roast chestnuts many years ago at a Victorian Evening in my home town. It was a crisp cold December night and there was a small crowd gathering around the heat of the vendor's brazier, their breaths frozen clouds. Being curious, I handed over what was then a lot of money - a princely 50 pence - and in return I was handed an inconceivably small paper bag, little bigger than a matchbox, containing just three chestnuts. Feeling somewhat disgruntled, I headed down the street peeling one as I went. But then I popped it in my mouth... and I was in heaven. Now I knew what Nat King Cole was singing about! In 1662 Evelyn spoke of them as 'delicacies for princes and a lusty and masculine food for rusticks, and able to make women well-complexioned,' and then lamented that in England they are chiefly given to swine...but pigs industrially fed on them in Spain and Corsica also produce the caviar of the ham world - Jamon Iberico. I still regard roast chestnuts and chestnut stuffing as one of the highlights of Christmas and for that reason December's Tree of the Month 2016 must be the Sweet Chestnut:

Sweet Chestnut (Castanea sativa) is a member of the Fagaceae family - all have fruits in the form of a nut either enclosed within a spiny or scaly capsule or held like an egg in a cup. The commonest native trees of the family are Oak and Beech, but Sweet Chestnut has been here for some 2000 years and might be considered an honorary native. In fact it was long thought to be a native and the suggestion that it was not sparked some controversy at the Royal Society in 1769, the arguments that it was native being perfectly sound at the time. The earliest written record is in the Forest of Dean where Henry II granted the tithe of Chestnuts to Flaxley Abbey and in the New Forest there was a boscus castanearis in the 14th century. But a clue to the tree not being native is the relatively little folklore and superstition attached to it - showing that much folklore derives from pagan times. Even so, it was only with the advent of pollen analysis that it was finally shown to be an introduction.

Sweet Chestnut can grow to 100 ft or more and live to a great age, developing enormous trunks in the process - as in the above pictured impressive tree at Canford School in Dorset. Even larger is the famous Tortworth Chestnut in Gloucestershire, which I must visit, already described as a tree of legendary antiquity in 1706. Its subsiding branches have now taken root to develop 17 secondary trunks that form a 'wood' 30 yards across, complete with bluebells, dog's mercury, lesser celandine and garlic growing beneath. And even bigger still, which I really must visit if I can ever afford it, is the Hundred Horse Chestnut growing on Mt Etna which had a stem girth of 190 ft when measured in 1780. Confusingly, the Hundred Horse Chestnut is a Sweet Chestnut, not a Horse Chestnut, but is so called as it is said to have sheltered Queen Guivanna and her entourage of 100 knights when they were caught in a storm. The tree has now split into multiple stems and is fenced. A larger tree on Mt Etna died, reportedly succumbing to the repeated cutting of branches to fuel the fires to roast its chestnuts. That's killing the goose....and having no stuffing.

The leaves, which are relatively insect resistant,  are large, narrow and glossy, somewhat leathery in texture, 7 to 9 inches in length, about 2.5 inches wide, tapering to a point at each end. The deep mid-rib gives rise to side veins, each a valley ending in a saw-tooth point at the leaf margin, ideal for making 'fishbones' - the careful tearing out the soft leaf tissue to leave the skeleton. The leaves remain on the trees late in autumn, turning to a golden colour before a coppery brown. They are very efficient with less than 1% of light wavelengths useful for photosynthesis passing through, meaning little can grow well beneath a dense canopy. They are the only part of the tree listed by Maud Grieve's Modern Herbal (1931) as having a medicinal use - an infusion made from steeping dried leaves in boiling water being used to treat 'paroxysmal and convulsive coughs, such as whooping-cough, and other irritable and excitable conditions of the respiratory organs'.

Sweet Chestnut is sadly vulnerable to 'Chestnut Blight' a disease that decimated the American Chestnut (Castanea dentata). Caused by a fungus, Cryphonectria parasitica, the disease acts much like Dutch Elm disease, rapidly killing the tree but leaving the roots alive to resprout and grow, only for the disease to kill again when the tree reaches a certain size - and so on ad infinitum. The disease was imported to America between 1882 and 1904 on Asian Chestnuts and within 20 to 30 years it had killed 99.9% (about 3.5 billion) of the American Chestnuts in its native range of the Appalachian mountains, destroying it as a commercial crop. Squirrel populations crashed and seven species of moth living on the American Chestnut are now extinct. At about the same time it was first noted in Europe - but here there is some hope because in several parts of Europe some infected trees appear to have recovered. This has been associated with less virulent strains of the fungus that are thought to be infected with a virus that appears to have reduced the severity of the disease when used as a biological control. The disease was identified in 2007 in Warwickshire and again just this year in Kent. In both cases the trees had been imported from infected areas and planted here. The trees were destroyed and surrounding areas surveyed, but unfortunately they had been in the ground for four and seven years respectively before the disease was identified. Since 2013 imports of plants or seeds must have 'passports' to show they are not from an infected area and that timber has been fumigated or kiln dried. (Feb 2017 update: The Plant Health (Sweet Chestnut Blight) (England) Order 2017 ( http://www.legislation.gov.uk/uksi/2017/178/contents/made ) came into force February 2017. It controls the movement of Sweet Chestnut material within certain distances of 'demarcated areas'. There are currently two demarcated areas in Devon. Full details here: https://www.gov.uk/guidance/plant-health-controls#quarantine-pestsor http://www.forestry.gov.uk/chestnutblight ) 

sources:
Bean W. J Trees & Shrubs Hardy in the British Isles 8th Ed. Forestry.gov.uk - Chestnut Blight. Grieves M, A Modern Herbal, 1931. Johnson H, Trees 1973. Mabey R, Flora Britannica, 1996. More D & White J, Cassell's Trees, 2003. Rackham O. Ancient Woodland (2003 ed); Woodlands, 2006. Smith, D, Delia's Happy Christmas. Tudge, C. The Secret Life of Trees. Thomas P & Packham J, Ecology of Woodlands & Forests, 2007. Wikipedia. Wikimedia Commons

The tree is native to the Cork, Kerry and Sligo counties of Ireland, as well as Portugal, Spain, Morocco, France, Greece and the Mediterranean Coast to Lebanon and Israel. It belongs to the Heather family, Ericaceae, and its 6mm pitcher shaped flowers are very reminiscent of heather itself. Strangely for a plant of the acid loving Heather family, the Strawberry tree will tolerate lime in the soil and in parts of Ireland it grows on almost bare limestone rock.

The flowers are a translucent creamy white, often tinged pink as in the photograph, hanging in panicles of 10 to 30, subtly cloaking the trees in autumn.  A deeper pink cultivar 'Rubra' has been cultivated since it was found growing wild in Ireland in 1835.

Strawberry trees have healthy glossy leaves that seem to suffer little from insect or other attack. The tree forms a dense rounded crown and tolerates salt well, making it useful in exposed coastal locations. It can grow to about 30 feet in height. The tree hybridises naturally with the Grecian or Cypress Strawberry Tree (Arbutus andrachne) where their ranges overlap and the resulting Hybrid Strawberry tree (Arbutus x andrachnoides) has inherited a degree of hardiness that the Grecian form lacks. This is fortunate as it will grow well here in sheltered locations and has an outstanding decorative bark.

Arbutus will tolerate most soil but avoid wet sites. They reportedly do not transplant well so use container grown plants whenever possible.

It's been a busy month and suddenly halloween night is here and there are just hours left to publish October's Tree of the Month before November arrives. I was tempted to skip it this month but I didn't want to let my fans down - I know they would both be disappointed. And so on the premise that a very short 'tree of the month' is better than none....

It's a great autumn for colour this year and so many species would make a good choice of subject this month - not least our native Beech which gives any tree a run for its money for autumn colour. But there is far too much to write about Beech and no time to write it, and so while on a quick trip to the shops today I snapped a few photos of the showy Claret Ashes in town. Fortunately, they are a relatively recent variety and so there is relatively little to write about them - meaning I should easily publish in time.

The Claret Ash, otherwise known as Raywood Ash is a variety of the Caucasian Ash, Fraxinus angustifolia subsp. oxycarpa . Caucasian Ash was originally introduced in 1815 as a species in its own right, F. oxycarpa, but has since been re-classified. The varient Claret Ash arose in the Raywood Gardens at Bridgewater near Adelaide and was introduced in 1925 when Nottcutts Nursery in Woodbridge grew them from imported bud wood.

The tree became more widely available in the 1970's and has been extensively planted in towns and gardens for its compact shape and, of course, stunning autumn show. I do recall some council tree officers reporting noticeable branch breakage in windy weather and it appears this is particularly the case where conditions have favoured rapid growth. The tree can also reach quite a large size; the oldest tree - planted soon after 1925 by Nottcutts - is at Kyson Hill above the river Deben. It has a girth of some 5ft and height of about 80ft. Mr R C Nottcutt presented  the land to the National Trust in 1930. The next largest tree is at Kew measured at 60 feet in 1971.

The Blackthorn (Prunus spinosa) should perhaps have been the tree of the month for October, when the fruit is best picked, or for March when it is the first of the hedgerow to blossom and signal the coming Spring. But they are fruiting now and I am reminded of one September when I managed to persuade my then young children to taste the blueberry lookalike fruit. I must confess to a shameful tendency to schadenfreude and, as they bit into the berries and their expressions changed to  pictures of utter shock and horror, I dissolved into helpless hysterics. With a taste that is described as 'astringent', I would add that in September it is the most unbelievably sour and bitter thing I have ever experienced. Your mouth is immediately sucked dry of any moisture and your face instantly screws itself into an agonised scrumple. Most domestic plums are thought to be an ancient hybrid between the Blackthorn and Myrobalan Plum, but mercifully the astringency was lost. But for sheer schadenfreude value, Blackthorn is Tree of the Month for September.

The Blackthorn is often seen as more of a suckering shrub or small spiny tree, found wild in Britain and Europe as well as north Asia. It is common hereabouts in Dorset and its fierce thorns make a good cattle proof hedge - the thorns are even known to puncture tractor tyres. As well as in hedges, it is abundant in scrub and woodland and, being very tolerant of salt spray and wind, is a useful first line of defence in coastal areas. The pure white flowers, 1.5cm in diameter, are unmissable in March when they appear on naked wood, singly or in pairs from the previous year's buds. A cold spell of weather at this time, as frequently occurs, is known as a blackthorn winter.

My ever trusty Flora Britannica, by Richard Mabey, quotes at length a description of the tree by William Cobbett, written 150 years ago. Even better, Cobbett's book 'The Woodlands' is digitised by google and available for free here. It is a super account of the tree and I follow Mabey's example by quoting much of it here:

' Everyone knows that this is a Thorn of the Plum kind; that it bears very small black plums which are called Sloes, which have served love-song poets, in all ages, with a simile whereby to describe the eyes of their beauties, just as snow has constantly served them with the means of attempting to do something like justice to the colour of their skins or the purity of their minds and as a rose has served to assist them in describing the colour of their cheeks.
These beauty describing Sloes have a plum-like pulp which covers a little roundish stone, pretty nearly as hard as iron, with a small kernel inside of it. This pulp, which I have eaten many times when I was a boy until my tongue clove to the roof of my mouth and my lips were pretty near glued together, is astringent beyond the powers of alum. The juice expressed from this pulp is of a greenish black, and mixed with water, in which a due proportion of logwood has been steeped, receiving, in addition, a sufficient proportion of cheap French brandy, makes the finest Port wine in the world, makes the whiskered bucks, while they are picking their teeth after dinner, smack their lips, observing that the wine is beautifully rough.... It is not, however, as a fruit tree that I am here about to speak seriously to sensible people: it is of a bush excellent for making hedges , and is not less excellent for the making of walking sticks and swingles of flails. The Blackthorn blows very early in the spring. It is a Plum and it blows at the same time, or a very little earlier than the Plums. It is a remarkable fact that there is always, that is every year of our lives, a spell of cold and angry weather just at the time this hardy little tree is in bloom. The country people call it the Black Thorn winter and thus it has been called, I dare say, by all the inhabitants of this island, from generation to generation, for a thousand years.
This Thorn is as hardy as the White Thorn; its thorns are sharper and longer; it grows as fast; its wood is a great deal harder and more tough; it throws out a great deal more side shoots; and it is, in every respect, better than the Hawthorn for the making of a Hedge....This Thorn will thrive, and that vigorously too, on the very poorest of land....The knots produced by [the] side shoots are so thickly set that, when the shoot is cut, whether it be little or big, it makes the most beautiful of all walking or riding sticks. The bark, which is precisely the colour of Horse Chestnut fruit, and as smooth and as bright, needs no polish; and, ornamented by the numerous knots, the stick is the very prettiest that can be conceived. Little do the bucks, when they are drinking their Port wine, imagine that the beautiful stick with which they are tapping the sole of their boot, while admiring their legs...by possibility for the 'fine old port' which has caused them so much pleasure, they are indebted to the very stick with which they are caressing their admired Wellington boots.'

Cobbett goes on to describe propagation of the tree. He seems to have been a colourful character; he was author, MP, campaigner against poverty and its causes, and one time inmate of Newgate Prison for libel. At the time of his death he was described as being paranoid to the point of insanity and was planning to write a play called 'Bastards in High Places' - which I think is rather splendid.

The fruit is more likely to be used to make Sloe Gin these days, rather than Cobbett's imitation Port. They are best harvested after a frost, which reduces the tannin content of the fruit. The skins of the fruit are punctured and covered with sugar, and then placed in a bottle to one third of its capacity, before it is filled to the top with gin. The contents are gently agitated over a period of at least three months, after which the contents are strained. The remains of the fruit can be mixed with melted chocolate to make sloe gin chocolate, once the liquid has been strained. If you collect in October it will be drinkable for Christmas but will still improve for another month or two.

Blackthorn is the traditional wood for hay rake teeth and for Irish shillelaghs, once described by the Chairman of the pharmacology Department of the University College of Los Angeles as an 'ancient hibernian tranquiliser'. A shillelagh is a highly polished stick of blackthorn wood that was made and used in Ireland, and a blackthorn walking stick is still carried by commissioned officers of the Royal Irish Regiment. Blackthorn wood is especially hard and takes a high polish. The shillelagh was used in self defence and is now used in a form of traditional fighting or martial art. Stout sticks of blackthorn are highly prized since it is rare to find blackthorn grown to this size.

Fireblight is a potentially fatal disease of trees and shrubs of the sub-family Pomoideae (those of the  Rosaceae family with apple-like fruits). Common hosts in Britain are Hawthorn, Apple, Pear, Whitebeam, Cotoneaster and Pyracantha. The disease is caused by the bacterium Erwinia amylavora which originates from the USA and was first recorded in Britain in Kent in 1956. The disease can cause significant losses in orchards and nurseries where large numbers of trees can be killed in local outbreaks and cropping of more resistant species seriously reduced.

The bacteria quickly multiply and spread to kill the inner bark of shoots and spurs, spreading into branches and even the stem, causing cankers and death of bark. If branches or stems are girdled by the infection, the branch or tree will die. The blackening of flowers and leaves can have the appearance of being scorched by fire, giving the disease its name.

The disease cannot be cured but the spread of infection can be stopped by pruning out infected branches. These should be cut well below the last sign of staining and in dry conditions. Pruning tools should be swabbed with methylated spirits between every cut. Infected material should be promptly burned.

The Oak Processionary Moth (Thaumetopoea processionea) is here and, 10 years after it was first spotted, it looks like it might be here to stay.... and it could be heading your way if it's not there already.

The moth is native to southern Europe where natural predators and climatic factors have tended to keep numbers in check. Unfortunately trade in plant material has led to a rapid expansion of its range over the last 20 years (as with a number of pests and diseases) and it is now established in the Netherlands and north Germany and has a foothold in the UK. The Forestry Commission now advise that it is considered impossible to eradicate the pest and that resources will concentrate on containing its spread. Some years ago I heard one London tree manager expressing deep frustration that he could not get the necessary budget and coordination to attempt eradication when the pest was first discovered in south west London in 2006. It was perhaps an opportunity missed and, some say, demonstrated a lack of policy and coordination in the management of urban trees at the time.

Despite control efforts, the spread seems to be inexorable and is now a major problem at some important sites such as Richmond Park, Kew Gardens and Syon House where enormous effort and expense is expended in removing nests. From the initial outbreaks found in several boroughs in West and South-West London and the Elmbridge and Spelthorne districts of Surrey in 2006, it was then found in the Pangbourne area of West Berkshire in 2010; Bromley, Croydon and Lewisham Boroughs in South London in 2012; Hackney, Waltham Forest, Tower Hamlets and Newham Boroughs in East London in 2014 and the Guildford District in Surrey, in 2015. A small number of nests were found in Watford this year and at the time of writing the critters are suspected in southern parts of Buckinghamshire and Hertfordshire.

This is not just bad news for Oak trees which are defoliated by the caterpillars, but also to us and to our animals. The caterpillars have thousands of hairs containing an irritant, thaumetopoein, which can cause itching skin rashes and, less commonly, sore throats, breathing difficulties and eye problems. This can happen if people or animals touch the caterpillars or their nests, or if the hairs are blown by the wind. The caterpillars can also shed the hairs as a defence mechanism, and lots of hairs are left in the nests, which is why the nests should not be touched. The greatest risk period is May to July, but they can be present on old nests, and could be blown or touched at any time of year.

The moths are named after their most distinctive identification feature, namely the manner in which the caterpillars form nose to tail processions when moving around the tree, or across the ground to move from one Oak tree to another. This video footage show one such column...they could almost be goose-stepping!

Whilst the implications to human and animal health posed by this caterpillar are currently the principal cause for concern, it could be increasingly damaging to the Oak trees. The larvae munch through the leaves and can strip a tree bare. This leaves them vulnerable to attack by other pests and diseases, and less able to withstand adverse environmental events such as drought and flood. It is possible that repeated heavy attacks could kill trees. Although the nests have only been reported on Oak, if they run short of oak leaves to eat, the larvae have been observed on hornbeam, hazel, beech, sweet chestnut and birch trees. Both of Britain’s native species of oak, pedunculate and sessile oak, and several other oak species grown here are susceptible to attack. In a very broadly descending order of susceptibility, they are:

Turkey oak (Quercus cerris), English or pendunculate oak (Q. robur), chestnut-leaved oak (Q. castaneifolia), white oak (Q. alba), Turner's oak (Q. x turneri), Holm oak (Q. ilex), Algerian oak (Q. canariensis), Hungarian or Italian oak (Q. frainetto), sessile oak (Q. petraea) and cork oak (Q. suber).

If you see this pest on your Oak trees you should report it to the Forestry Commission using the tree alert facility on their website  . To be most effective control measures should be carefully timed and carried out by professionals with appropriate training and equipment. Do not try to remove caterpillars or nests yourself, because of the health risks.

The Forestry Commission advises:

• DO NOT:
• touch or go near nests or caterpillars
• let children touch or go near nests or caterpillars
• let animals touch or go near nests or caterpillars
• try to remove nests or caterpillars yourself.
• 
  
• DO:
• teach children not to touch or go near nests or caterpillars;
• train or restrain pets from touching or going near nests or caterpillars
• see a pharmacist for relief from skin or eye irritations after possible contact
• call NHS111 or see your GP if you think you or someone you care for has had a serious allergic reaction
• speak to a vet if you think your pet or livestock has been affected;
• call in a suitably qualified pest control expert to remove infestations in your trees
• warn any neighbours who have oak trees that they might also have an infestation

Control efforts have currently seen the establishment of 'control zones'. It is intended to contain infestation within the 'Core Zone' which includes boroughs of Ealing, Richmond, Hammersmith & Fulham, Hounslow, Kensington, Chelsea and Kingston, as well as parts of Brent, Merton, Wandsworth, Westminster and Elmsbridge. The 'Control Zone' is a bufferzone of surrounding districts and where some presence has been found. The 'Protected Zone' is currently (largely) unaffected areas. Government policy is to contain spread from the West London 'Core' outbreak, and to eradicate it elsewhere. In general terms, Forestry Commission England will take charge of all aspects of treatment of privately owned infested trees in the Control and Protected Zones in 2016, and there will be no costs for the owner. In the 'Core Zone' control by owners is 'strongly advised' but it would appear that no help is offered. This can only be due to the scale of the problem and cost of control. But without determined efforts in the Core Zone, there will surely be a perpetual need for vigilance and control in the Control and Protected Zones. The current efforts must certainly have restricted its progress, but if containment isn't completely effective, there must surely be an exponential expansion of its presence across the country.  Lets hope this has taught us to act swiftly and thoroughly when the next pest arrives because, despite Brexit, it surely will.

For information about regulations and requirements applying to the importation of oak plants, or to the movement, handling and disposal of oak material in affected areas, contact the Forestry Commission's Plant Health Service.

T: 0300 067 5155
Email: plant.health@forestry.gsi.gov.uk

Rather unhelpfully, the Pride of India tree comes from China (where it has often been a symbol used to mark the graves of scholars). Equally confusingly, its other common name, Goldenrain tree, is shared with Laburnum; so I tend to stick with the Latin - Koelreuteria paniculata.

Koelreuteria is another tree that has to be on the short list for smaller sunny gardens. It has attractive foliage, provides a striking mid-summer floral display, and has fiery autumn colour.

It belongs to the Soapberry family (Sapindaceae) which has lately been expanded to include the Maples and Horse Chestnuts. It is hardy, tolerates a wide range of soils, drought and air pollution, making it suitable for many locations - including as a street tree. The wood is quite brittle though and some shelter can help.  The tree was introduced in 1763 and is said to have first been cultivated in Croombe, in Worcestershire. It is named after J. G. Koelreuter, a professor of botany at Karlsruhe (1733-1806).

The tree can attain 30 - 60 feet in height and can be rather gaunt in habit when young, becoming more compact with age.

The phytochemistry of Koelreuteria paniculata is known to be quite diverse and it has a medicinal reputation that includes antioxidant and anti-tumor activity.

The tolerance of Koelreuteria to a wide range of conditions and its ability to set viable seed mean that it is becoming invasive in Florida and Hawaii where it can out-compete native vegetation. Who knows, a touch more global warming and it will begin a march through our woodlands?

Limes (or Linden or Pry) make some of the most beautiful of our landscape trees. They were once thought to be a relatively minor component of our prehistoric woodlands due to the relatively low proportion of Lime pollen found in pollen analysis studies. But, being pollinated by bees, they shed far less pollen than wind pollinated species and, factoring this in, we now know that it was the most common tree of lowland England, from the south coast north to the Lake District and the Tyne - with the exception of Cornwall which was predominantly Oak and Hazel - but then some consider Cornwall separate from England anyway. (While on the subject of bee pollination, there has long been concern that Lime is toxic to bees - more below under Silver Limes).

Large areas of Lime were cleared by Neolithic and Bronze Age man for conversion to farm land. This was an immense achievement given the tenacity of the species and its ability to re-sprout. The largest remaining Lime wood is Shrawley Wood in Worcestershire (340 acres) and this and another - Lynwode Wood in Lincolnshire - fell into the hands of the unreformed Forestry Commission who immediately set about doing their usual thing, which was clearing the native trees to plant exotic conifers. The trees were felled and poison applied - Ecologist George Peterken described the air as being 'acrid with herbicide' - but Agent Orange had met it's match and the Limes stools gradually recovered 'over-topping the drought bitten Norway Spruce'. 20th Century Forestry Commission had thrown all it's science at the Limes and failed to achieve what our ancestors had managed with hand tools.

We know that Limes woods were still common as late as Anglo-Saxon times partly from its frequency in place names. Lyndhurst and Linwood in the New Forest near us derive from 'Linde', the Anglo-Saxon for Lime. There is also good documentation from the use of coppice poles and from 'bast' - a fibre made from the inner bark and spun into ropes and mats - giving rise to more place names such as Bastwick in Norfolk.

Grazing by deer, goats and sheep has been suggested as another reason for the loss of Lime woods. Oliver Rackham describes it as 'relatively unattractive' to deer, but also notes their absence from the New Forest, Epping Forest and the Forest of Dean (a Forest with a capital 'F' is - or was - a royal deer hunting park). Furthermore, in areas of Oak and Beech such as in South Wales and the Avon Gorge, Limes can be found on inaccessible cliffs - suggesting a sensitivity to grazing.

Climate change, conversion to farmland and grazing have probably all contributed to the decline of Lime woods, but the extent of loss remains something of a mystery.

Naturally occurring Common Lime is not at all common and tends to differ slightly from the variety that has been so ubiquitously planted in streets, parks, avenues and churchyards throughout Britain - earning it the 'Common' name. This variety is almost certainly from stock imported from the continent in the mid-seventeenth century. It has a propensity to form suckering shoots at the base and it was learned at an early date that when the tree was felled and the shoots were pegged down, new plants were produced easily and cheaply. However, removal of suckers has also proved to be an onerous maintenance task for municipal authorities where this feature was undesirable.

There has been concern that the nectar from Lime trees is toxic to bees, none more so than Silver Lime and Silver Pendent Lime, beneath which large large numbers of 'drunk' and dead bees have been found. The fear was reinforced by the fact that a tea, tilleul, has long been made from an infusion of the flowers and used to aid sleep - even being recommended as a mild sedative during the war - suggesting narcotic properties. Tea made from the Silver Limes was thought particularly effective. This has led to calls for trees to be removed - or at least not be planted in certain locations. However, research has shown that the phenomenon is a result of bee behaviour rather than toxic nectar. It is bumblebees rather than honey bees that are affected, and the workers only live for a few weeks. Silver Limes flower later than others and the Bumblebee Conservation Trust currently advise: 'There has been a lot of research into the reason why and the current evidence points to the behaviour of bumblebees, and not toxic nectar. For some reason, bumblebees keep feeding upon the flowers, even when nectar runs low. So on hot days, and close to the end of the flowering period, the bumblebees keep feeding, run out of energy, and die. Honeybees, however, seem to realise that there is no nectar left, and will feed upon other flowers instead'.

This blog largely produced from works of Oliver Rackham, Richard Mabey and W J Bean.

More Limes to follow...we would love to include your photographs of Lime species too - please send them to us!

June's Trees of the Month is a two for the price of one: the Snowdrop and Snowbell trees. It is to be a very short blog for the very good reason that I know very little about them - other than that  they are beautiful trees that are too infrequently planted and deserve a mention, even if it is a necessarily brief one. They may not smack you in the retina like some of the Cherries, but if grace and elegance are your thing, they might be the trees for you! I find it easy to to confuse the two due to the similarity of their names and also of their flowers, so I for ease I combine them here. In any case, they are both in the family Styracaceae so I have some excuse for doing so.

This is the Japanese Snowbell, Styrax japonica - I think I can be forgiven for confusing it with the Halesias or Snowdrop trees. Although closely related, they are different genera with distinctly different fruit - Styrax fruit being small round dry drupe-like fruit with two seeds.

There are about 130 species of Styrax across America, East Asia and Malaysia and just one native to Europe. Probably the most frequently planted in Britain, and deservedly so, is the Japanese Snowbell, Styrax japonica, a small tree of 10 - 25ft with graceful slender spreading and sometimes drooping branches. The pure white flowers hanging along the undersides of the branches are delightful viewed from beneath. I had the perfect spot for one in my garden, on top of a bank beside a path running alongside the house where, as you passed, you would have a stunning display arching over your head. I duly set out to acquire one about 15 years ago but, given the choice between the Japanese Snowbell and the rarer Hemsley's Snowbell, Styrax Hemsleyana (or, less attractively named Hemsley's Storax), I opted for the Hemsley's for no better reason than that it was rarer - after all it couldn't be that different could it?......