The long-lived mulberry can be a delightful choice for a garden tree. It needs little care, and will eventually produce a crop of delicious fruit.
There are about ten species of mulberry tree, but only two or three are actually cultivated, and only Morus nigra, the black mulberry, is grown for its fruit. (Another species, which has bland, white berries, is grown commercially as a host for silkworms.) Mortis nigra produces heavy crops of lovely dark red to black berries. Mulberry trees grow-naturally in most areas where the climate is fairly mild. They were introduced into Britain in the early seventeenth century. The trees can live for several centuries, and some of these original specimens are still alive.
Mulberries are an increasingly popular choice for a garden tree. They are relatively small, with a maximum height and width of about 6-9 m (20-30 ft) when mature, they require little pruning, and are usually disease-free. You do have to be patient, however, and wait about eight years before a young, nursery- bought tree will start fruiting. Several nurseries now stock mulberry trees. Be sure to choose a strong, healthy specimen.
Spring is the best time to plant a young tree. As mulberries are slightly tender plants, choose a site which is sheltered, especially if you live in cooler parts of the cold temperate area. The soil should be deep, rich, and well-drained but moisture retentive.
Prepare the planting site by digging a hole large and deep enough to take all the roots of the tree comfortably. The roots are very brittle and, if you damage or cut them at planting, they will bleed severely and the tree may suffer a permanent check.
To plant, place the tree in the prepared hole, allowing the roots plenty of room to spread out. Plant it to the depth of the soil mark on the stem. Sprinkle a few handfuls of peat over the them immediately roots, and then return the soil to the hole. Tread the soil down to firm it and water the area.
You may want to apply a mulch of” well-rotted manure, garden compost, leafmould or damp peat to keep down weeds and retain moisture. Apply it in a ring around the tree as far as the branches extend, but do not let it touch the tree stem, or it may rot the bark.
Care for new and established trees is similar. No special formative pruning is needed for mulberries; indeed, pruning should be avoided because of the tree’s tendency to bleed. Pruning should be limited to the thinning out of crowded shoots and branches in winter. Even so, this should be carefully kept to a minimum, as the tree will bleed considerably from any wounds.
There are three methods of growing mulberry trees in your garden: as free standing standard trees or bushes, as pyramids and supported on walls.
Standards require only the removal of dead wood, as described above. Pyramid trees must be trained by carefully shortening the lateral growth so that it forms spurs. This should be done in mid-summer. If you are growing your tree against a wall (a good idea in cooler areas) train the branches about 30 cm (1’) apart, and cut back any side-shoots to form spurs in mid-summer.
It is possible to propagate mulberry trees from cuttings. Make cuttings in mid-autumn of that season’s growth; the cuttings should be at least 30 cm (12”) long, with a 7.5 cm (3”) long heel of old wood. Put the cutting into a well- drained, sandy soil, in a protected position, to half its depth. The roots should start to form during the winter or early spring, and the cutting will be ready for planting the following autumn.
You can also grow mulberry trees in pots. These will need to be repotted every year, and will probably need to be planted out after about five years. There are small, potted mulberries available from specialist nurseries.
All mulberry trees, however they are grown, require occasional watering, and they will need frequent watering during dry weather. Trees which are fruiting will also benefit from an occasional watering of liquid manure. As the tree matures, the crooked branches become even more knarled, and they will probably need to be supported with poles. Older, established trees almost always require some sort of support for the branches.
The fruit of the mulberry tree begins to ripen in late summer. Ripening is irregular, and the fruit is available over quite a long period. The fruit is slightly acid when under-ripe, and is delicious then, when made into jams, tarts or other dishes. Leave it to ripen fully on the tree, and you will have lovely, almost black, sweet berries to serve with cream for dessert. But remember that the dark red juice will stain everything it touches, including your hands, and can be hard to remove. Also remember that mulberries are one of the favourite treats of birds, so protect your crop by netting the tree.
Pick mulberries by spreading a sheet on the ground and gently shaking the branches. Most of the berries will fall off when ripe and can be gathered right off the ground—if you beat the birds and squirrels to them. Shake the tree carefully, as the wood is very brittle and can break.
Mulberry trees are almost free of any garden pests or diseases. Only canker attacks the trees, and this is rarely severe enough to need treatment.