The Westmorland damson is a variety of Shropshire Prune and is said to be the 'Blue Violet' although this is now doubtful. It would be reassuring to know for certain and attempts are being made to verify this by comparison of stones and DNA testing.

A damson tree will develop different characteristics in different locations and the prevailing climate. Small variations may be observable within a distance of only a few miles and thus there is no authoritative identification process. This note will describe characteristics observed in the damsons growing around the Lyth Valley in the old County of Westmorland.

Thefruit

The typical Westmorland damson fruit lies in the range of 27 to 30 mm long and 20 to 23 mm in diameter. However if the crop is sparse the fruits may grow larger, and conversely a heavy crop may produce many small damsons, especially in a dry season. The fruit will be somewhat oval in cross section and tapered towards the stalk rather like a stubby pear. The ovality may not be completely symmetrical. There is often a very small collar where the stalk meets the fruit. It is unusual to find a mark or groove running lengthwise down the fruit as is so obvious in some plums but a faint lengthwise mark may very occasionally occur. The stalk usually comes away with the fruit when picked and will be about 18 to 20 mm long.

A damson is never spherical. A spherical fruit will probably be a cultivated plum, a wild bullace or a sloe.

The Westmorland damson will be a blackish purple in colour and as it approaches ripeness will he coated with a bloom of natural yeast often making the fruit more blue than purple.

The inside flesh of the damson will he greenish yellow at first, becoming more yellow as the fruit ripens. At no time, even when the fruit is very ripe will the stone readily part company with the flesh.

Thestone

The stone itself is asymmetrical and when viewed from the side, with stalk end to the left, will have a slightly more pronounced curve on the lower ridge than the top. At the stalk-end the stone may even show a small upward curving tip. There are two lengthwise grooves on the stone along the ridges, the one on the more gradual curved ridge at the top will he more or less along the crest but at the bottom, where the ridge is more curved it may be slightly offset to the side.

The stone is likely to be between 15 to 18 mm long and no more than 10mm in height and will be smoother than many other plum and damson varieties. These often show marked and very rough grooving. With experience it is possible to identify damson va rieties from the stone alone.

Theleaves

The leaves of the tree are symmetrical, the points more rounded than sharp and become larger and more rounded as the tree gets older. Young trees up to about 6 feet tall may have quite sharp leaf points. Leaves on a mature tree are likely to be 60 to 65 mm in length. Most other damson varieties will he larger.

Thetree

Unless it has been budded or grafted onto a dwarf stock, which is rarely the case in Westmorland, the tree itself will have a tendency to be leggy often reaching over 6 metres high in old age. The trunk rarely exceeds 200mm in diameter even in old trees.

Thebark

Only in ancient trees is the bark likely to show numerous deep longitudinal fissures. There may be occasional long splits due to bursts of rapid growth in wet seasons but in trees up to 40 years old the bark may simply be uniformly rough, resembling extremely coarse sandpaper, very different from the fissured bark of, for example, a pear tree. It is rarely shiny smooth unless the tree is very young and then the bark may resemble that of a hazelnut tree.

On mature trees there may be a fairly uniform layer of lichen on the trunk appearing as a green or brown powder, the occurrence depending on the climatic conditions thus lichen may possibly he observed in other damson varieties. Occasionally the bark of a Westmorland damson may carry shallow circumferential markings, a less distinct version of those on wild cherry trees.

Theroots

Westmorland damson trees are shallow rooted rarely going below 2 feet and because of this when planted in shallow soil have a greater tendency than others to produce suckers from the roots up to some distance away from the trunk. This tendency may increase as the tree grows older. Damson trees are prone to wind damage and uprooting and although there are trees over 100 years old, the Westmorland damson reaches its peak betwen 20 and 30 years of age.

Theseasons

The local climate will affect the blossoming and fruiting seasons. In Westmorland the blossom starts in very early April and has been seen in late March. The fruit picking season is the first 3 weeks in September but with mild springs is becoming slightly earlier. Blossoming and harvest is usually a little later in the exposed parts of north Westmorland and in Cumbria.

Theflavour

If there is an opportunity to compare the flavour with other damson varieties the Westmorland damson, when cooked, will have the stronger amaretto flavour loved by cooks and chefs everywhere.

Conclusion

In general, the larger the fruit and leaves the less likely the damson is to he a Westmorland damson. A south country damson for instance may be up to 25% larger in both.

By: Peter Cartmell

© Westmorland Damson Association 2000

Damsons are very tolerant of altitude, soil type, acidity and alkalinity. They are not very deep rooted and will tolerate anything but solid peat and heavy clay. There are damson trees in Scotland so they will grow fairly far North. They like a damp climate, except at blossom time, when it interferes with pollination. They do not like their roots to stand in swampy conditions.

Prolonged rain when the fruit is well formed causes the fruit to expand rapidly, sometimes splitting the fruit, which spoils the appearance and keeping qualities rather than the taste.

Damsons cannot tolerate being overshadowed by larger trees and even the under-branches of damson trees, being deprived of light, tend to die back.

Cutting out this dead material improves the tree and eases picking. Damson trees in turn will tend to keep down other bushes which grow underneath them. Some people do not like damson trees in hedges for this reason although alone, if trimmed, they make reasonable but not stockproof hedges. They were often planted along the edges of fields in Westmorland, close to walls in many cases.

Damsons can be grown from damson stones but the stones are difficult to germinate and the resultant tree could vary slightly from its parent in its cropping propensity. Certain firms specialise in preparing stones for propagation and the Westmorland Damson Association has had one batch of stones grown into small seedling trees. In nature, like some other seeds, they might have to be eaten by birds or animals to make them fertile. Damson stones are a favourite diet of Hawfinches, and sheep and pigs enjoy eating the fruit.

Westmorland damsons are a type of Shropshire Prune, possibly the Blue Violet. They are smaller but certainly have a better flavour than damsons from further South such as Cheshires or Merryweathers (Nottingham). Damson trees purchased from plant nurseries and garden centres will almost always be one of these southern varieties. Many damsons available in supermarkets are from the Continent and are very bland.

In addition to the germination of stones, the Damson Association is starting to experiment with grafting on to local and also dwarf stocks such as St Julien. Generally, however, Westmorland Damson trees are not grafted onto a different rootstock and this means that the shoots which sprout up from the roots of a mature damson tree, called suckers, are genetically the same as the parent tree and can be separated and planted to provide new trees. Most mature damson trees will have suckers, perhaps several yards from the main tree, unless they are grazed or mown off. These suckers may be separated and dug up at any height from six inches to six feet. They are likely to have very little root but growth is usually successful.

Before planting a sucker or seedling, a small area say three feet diameter, should have the grass removed by digging over or by using a weedkiller such as "Roundup". A little manure or other fertiliser may be dug in, but in many cases nothing at all is put down and the tree still grows and crops well. Some people put in a small amount of John limes or similar when planting to give them a start.

Transplanting is best done in November/December but any frost-free time during the winter seems suitable. Precautions should be taken against deer as the young bucks will strip off the bark when rubbing, in their territory marking routine, as well as eating young growth. Rabbits will also damage small suckers.

Small diameter tree tubes do not work too well for protection as damson branches seem to object to being crushed back. Wider guards, or best of all, full deer fencing is recommended. Clematis netting in a tube shape is useful for the protection for individual trees. In the early stages it will be necessary to water the young trees, particularly if the summer after planting is hot and dry.

Damsons are self-fertilising but may crop better if planted in groups spaced at least 5 yards apart. If left alone they tend to form thickets as the suckers grow between the trees.

In the early years of growth it is sometimes advisable to cut the end ofFthe leader shoot and possibly the ends of spreading branches to keep the tree within manageable dimensions. This is best only done once and should be done in the summer months to prevent infection by the Silver Leaf fungus. Pruning, with the exception of the above and thinning the dead branches, is best not done.

Damsons in a hollow are more prone to frost than in open ground. This will not harm the tree but might affect the crop in some years. The suckers will crop when about 8 years old, usually when they are about five feet high. Not every year will produce a good crop. Some people claim that you get a bumper crop about every 7 years, followed by a bad year, but a very important factor is the weather at blossom time. Exposure to cold winds may be as damaging as frost, and poor weather will discourage the insects which assist pollination.

© Westmorland Damson Association 2000

Pruning is done mainly to: keep the tree in good health, produce a pleasing and manageable shape and ease picking.

Many people worry too much about pruning damsons, traditionally in Westmorland they have been left alone. This can of course result in a very tall tree with top branches very difficult to pick.

It is usually sufficient when pruning, to clean out the dead and damaged wood which tends to form under the canopy reducing light, looking untidy and making a barrier of small scratchy branches which are a nuisance when picking.

To prevent excessively tall growth it may be advisable to cut the top off the leader shoot when the tree is young and about 6 feet tall. Damson branches get brittle when elderly and if a very vigorous young branch is growing almost horizontally, it might be advisable to trim the end of this too otherwise it may snap off in later years in snow or storms.  Some growers retain and support these long branches by using props, as a horizontal branch does contribute to the show of blossom and is easy to pick.

Damson blossom is attractive and if the tree is grown for appearance rather than crop the height and shape of the tree may not be so important. Wood that has been removed should not be allowed to decay around the tree as it is likely to contain spores of a variety of fungus infections.

As damsons blossom in early to mid April, it is recommended to prune fairly quickly after the blossom has fallen. This is said to reduce the incidence of Silver Leaf which is one of the fungi mentioned above.

Damsons trees are fairly resistant to rot as they exude a gummy sap when cut, which helps to seal the wound. It is not usually necessary to remove large branches but if this is done branches should be cut offclose but not into the main stem. It is inadvisable to attack a mature tree by heavily cutting back main leaders and branches. If for some reason this has to be done, it is possibly better left until the Autumn. Very drastic pruning should be spread over two or more years to lessen the effect on the health of the tree. An old damson tree will sometimes die if cut back too far.  Survival is unpredictable and occasionally the result of heavy pruning is a number of new strong vertical shoots near the cuts which look rather out of place.

It has been known for growers to leave the removal of tree tops or high branches until fruit picking time in late September so as not to waste the fruit on these normally inaccessible places. No serious damage results.

A properly cultivated damson tree should look uncluttered, open and fairly symmetrical in shape. If it looks pleasing it is probably all right. If a damson tree is not producing fruit it is unlikely that pruning will improve matters.

If a tree is elderly, extremely misshapen, too tall, or too near property, it is often advisable to let a root sucker grow as a replacement and fell the old tree when the sucker is a few feet tall and can be seen to be healthy and well established. These suckers may be transplanted if necessary.

Damson trees tend naturally to grow into rather a tortuous shape. Apart from aesthetics and picking problems this does no harm. Very little pruning is done in commercial damson orchards simply to produce a better shape. As these growers have found, it is probably better to leave things alone.

The above advice is for normal orchard trees. Although not done locally in the Lyth Valley, it is possible to train damsons into fans and other shapes. Anything possible for plums is likely to apply to damsons.

By Peter Cartmell

© Westmorland Damson Association 1999