Plums prefer heavy calcareous soils of good depth and rich in nitrogen, but will grow on a fairly wide range of soils if well drained.
In the early stages, plums usually grow very rapidly, and nitrogenous manures are not generally required for the first few years. Potash is necessary to produce balanced growth. There is no evidence that phosphates are very important here. Under arable conditions they would hardly ever be used. As soon as the trees begin to crop, nitrogen becomes necessary to enable good growth to be made, especially with such heavy cropping varieties as Victoria. Sulphate of ammonia (21% N) or nitro chalk (21% N) is often applied in January, at about 45 g/sq.m and it is as well to give 10 g/sq.m of sulphate of potash as well. In private gardens where dung is often available in moderate quantities, a liberal dressing of well-decayed stable manure in early spring is of great benefit.
Note: g/sq.m – grams per square metre, 45 g/sq.m is roughly 1 ½ oz per sq.yd.
Plums are usually budded. Myrobalan B is now generally regarded as one of the best of the plum stocks for most varieties. It makes a vigorous tree capable of bearing heavy crops, and in trials at Long Ashton and elsewhere, crops have been very good indeed on this stock, with the exception of Pond’s Seedling and Victoria, which do not succeed. It is somewhat susceptible to silver, especially when worked with Victoria, Yellow Egg and Blaisdon Red.
Myrobalan B has also proved to be resistant to attacks of bacterial canker, and where this disease is known to be troublesome, this stock is used as a-builder, the stock being high-worked with the desired variety. Trees built up in this way should.be kept in the nursery a year longer than low-worked trees.
The varieties Pond’s Seedling and Victoria do well on St. Julien ‘A’, which is compatible with all varieties and produces a medium sized tree. This stock is also useful for working certain gages (e.g. Oullins) which may be incompatible with Myrobalan.
During recent years it has become the custom in districts where bacterial canker is troublesome, to high work plum trees, using a resistant stock to form theof the trees. Pershore Yellow Egg, Warwickshire Drooper and Myrobalan B have all been used for this purpose. There is an increasing interest in St. Julien ‘A’ and Pixy rootstocks for new plantings. Pixy may be very helpful in growing dwarf bush trees.
It is a common saying that the less stone fruits are pruned the better, but some training and shaping is of course necessary in the early years and thinning is usually required when the trees get older. Maidens should be cut back to a good bud 1 m above the union of stock and scion for bushes, and 1.3 m for half standards. The second year cut back the resulting growths to half their length. As soon as the trees begin to crop/ generous manuring must be carried out if the trees are not to become stunted. Allof fruiting plums should be done in summer to minimise infection by silver leaf.
Any large cuts must be painted with Medo or a similar fungicidal tree paint. Great care must be taken with plums to cut to an upward-pointing bud, owing to the pendulous habit of most varieties. This explains why many growers prefer to grow plums as half standards.
A Maiden is a one year old tree, or a Maiden Shoot is one season’s growth in that season.
Varieties of plum Dessert
Cambridge Gage Oullins Golden Gage Donne de Bry Jefferson’s Gage Merton Gem Thames Cross Severn Cross
Victoria (also used as dessert)
Pershore Yellow Egg
Most widely grown varieties commercially.
Varieties for canning
Victoria and Pershore (Yellow Egg) are preferred for canning; also Warwickshire Drooper (a mid to late September variety which is often grown on its own).