Soil:
Mulberries like a warm, well-drained soil, preferably a deep
loam. Shallow soils such as those frequently found on chalk
or gravel are not recommended.
Irrigation: Although somewhat drought-resistant, mulberries
need to be watered in dry seasons. If the roots become too dry
during drought, the fruit is likely to drop before it has fully
ripened.
Fertilization:
Mulberries generally thrive with minimal fertilization. An annual
application of a balanced fertilizer such as 10:10:10 will maintain
satisfactory growth. In California mulberries usually need only
nitrogen.
Pruning:
No special pruning techniques are needed after the branches
have been trained to a sturdy framework, except to remove dead
or overcrowded wood. A mulberry tree can be kept to a tidy form
by developing a set of main branches, and then pruning laterals
to 6 leaves in July in order to develop spurs near the main
branches. It is not advisable to prune the trees heavily since
the plant is inclined to bleed at the cuts. Cuts of more than
two inches in diameter generally do not heal and should be avoided
at all cost. The bleeding will be less severe if the tree is
pruned while it is dormant.
Pests
and Diseases: Mulberries are generally free of pests
and diseases, although cankers and dieback can occur. The ripe
fruit is very attractive to birds, but there is usually enough
fruit left over for harvesting.
Harvest:
White and red mulberry fruits (and hybrid fruits) are ready
for harvest in late spring. The fruit of black mulberries ripen
in summer to late summer. The fruits of white mulberries are
often harvested by spreading a sheet on the ground and shaking
the limbs. A surprising quantity can be gathered from a comparatively
small and young tree. Black mulberry fruits are more difficult
to pick. As the berries are squeezed to pull them loose, they
tend to collapse, staining the hands (and clothing) with blood
red juice. Unwashed the berries will keep several days in a
refrigerator in a covered container. The ripe fruits of the
black mulberry contain about 9% sugar with malic and citric
acid. The berries can be eaten out of hand or used in any way
that other berries are used, such as in pies, tarts, puddings
or sweetened and pureed as a sauce. Slightly unripe fruits are
best for making pies and tarts. Mulberries blend well with other
fruits, especially pears and apples. They can also be made into
wine and make an excellent dried fruit, especially the black
varieties.