Failure to Fruit
One of the biggest problems for in-experienced fruit growers is the tree that fails to fruit. When this happens occasionally, it can usually be attributed to bad weather at blossom time. In order to set fruit, blossom must be fertilized and with some fruits the pollen, to effect fertilization, must be brought from other neighbouring trees. This is largely the work of bees, though other insects and wind assist. If weather is wet or cold when blossom is open there may be too few bees about to effect pollination or the pollen may be too damp to be readily blown about by wind.
Another possibility is that the blossom itself has been damaged by frost. The trees themselves may be perfectly hardy but fruit blossom is not. Even a few degrees of frost, continued for an hour or so, is sufficient to damage it so badly that it cannot be fertilized, and this is quite likely to happen in spring in low-lying places where cold air can collect.
There is not much that can be done about weather damage to fruit blossom except to avoid planting fruit in cold hollows. Sometimes it is possible to protect small bushes or wall trees with netting or old curtains, and strawberry flowers may be protected by placing cloches over the plants.
Other Reasons for Failure
Quite often failure to fruit can be traced to a quite different cause – failure to flower. If there are no flowers there cannot be any fruits, and lack of flowers may be due to incorrect pruning, the use of an unsuitable rootstock, bad feeding, or it may simply indicate that the tree is too young.
Some fruit trees only bear if they are fertilized with pollen from another fruit tree of the same kind but of a different variety. Commercial apple growers always plant two varieties together for this reason; for example, apple Cox’s Orange Pippin with apple Worcester Pearmain. The lone fruit tree is often barren because it lacks a mate or, if it has one, the mate flowers at a slightly different time or produces pollen which is incompatible. All good fruit nurseries can give advice as to which varieties pollinate each other most effectively.