Fruit: unproductive trees

As long as fruit trees are producing a reasonable harvest of tasty fruit, they earn their place in the garden. If crops diminish, stop, are produced biennially, or are composed of many small fruits of poor quality, one or more elements within the cultivation regime or climate may be to blame.

Unproductive fruit trees
Unproductive fruit trees

Quick facts

Common name Unproductive fruit trees
Plants affected Apple, apricot, cherry, nectarine, peache, pear and plum
Main causes Various, including poor pollination, over-pruning, lack of water and feed
Timing At flowering time or when fruit should have set

What unproductive fruit trees?

When a fruit tree crops badly or fails to produce fruit, it is termed ‘unproductive’.

Symptoms

A poor crop may be seen in one or more than one of these situations:

  • In spring, there are long stretches of bare wood with the occasional tuft of leaves and flowers, often at the ends of the branches
  • A large crop of small apples may be produced
  • Fruit such as apples and plums may fruit in alternate years. This is known as biennial bearing
  • A generally poor crop, but vigorous growth
  • Performance may decline over several years

Control

To help ensure your trees are a fruitful as possible;

  • Check the pollination requirements of your fruit tree
  • In frosty periods, consider protecting smaller trees and trained forms such as fans in flower. Use horticultural fleece, ensuring that it does not rest on flowers. Use canes to support the fleece and remove during daytime to allow pollinating insects access
  • Ensure that fruit trees are planted in grass- and weed-free areas, to make watering easier and allow fertilisers and mulches to be applied
  • If trees such as apples and plums are producing fruit in alternate years, this indicates a problem with biennial bearing
  • Pruning fruit trees correctly and at the right spacings will help give good crops, allowing air and light in and encouraging production of fruiting wood
  • If trees have become neglected, renovation of apples can be carried out in winter. Summer is the time to renovate stone fruits such as plums so as to reduce the risk of diseases such as silver leaf and bacterial canker
  • Fruit trees, especially ones that are not grown on dwarfing rootstock, will not produce a good crop until their fourth year. Any fruit formed before this should be removed as soon as seen, unless the trees are on dwarfing rootstock when cropping can begin within two years

Cause

There are many possible causes of poor crops of fruit, from environmental conditions and pests or disease to more controllable causes, including overpruning or underfeeding

If no buds are present after winter, birds such as bullfinches may be to blame. As winter food becomes scarce, birds will eat buds of cherries, plums and pears

If flowers are borne, but little fruit develops:

  • Pollination may have been poor. Most apples need one or more pollination partners to produce fruit. Other fruits can be incompatible with each other
  • Frost and low temperatures can affect all fruits, but especially the early flowering plums, nectarines and peaches, by damaging the fruit buds. Spring frosts are the commonest cause of poor fruit crops
  • Bees are also less active early in the year, especially in unfavourable weather
  • A lack of water at fruit-set and swelling. Both young and mature fruit trees  need good supplies of water throughout spring and summer
  • Sunshine, shelter and adequate fertiliser are all needed for healthy growth and fruit
  • When trees (apple, pear and plum) produce fruit in alternate years, it is known as biennial bearing and has several possible causes, including lack of moisture and food
  • Apples often go through a natural thinning process known as June drop. However, similar symptoms on cherries can lead to complete fruit failure
  • Pests such as apple sawfly, codling moth, pear midge and winter moth can all lead to crop failure

If there are no flowers or flower buds present at all:

  • Over-pruning or poor pruning may be to blame. Vigorous shoot growth at the expense of fruit is often caused by taking too much wood out of a tree in one year. The tree’s energy is put into compensating for the lost foliage at the expense of fruit. Poor pruning may also result in a large crop of very small apples
  • If the tree has become overgrown, rejuvenation is possible over several years
  • A fruit tree declining in yield may not have established properly after planting
  • Another reason for poor fruit cropping can be immaturity of the tree. It can take a number of years until cropping starts. If trees are bought at one or two years old, it is likely to be another two or three years before you can expect a reasonable harvest. Those on dwarf rootstocks are least likely to suffer a delay in coming into bearing

For growing techniques for specific fruits, please see our individual profiles;

Apples
Grow Your Own fruit

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