There are many possible reasons why your tree is failing to fruit. Pick the question that describes the situation closest to your own, and discover a solution
Q My young tree is in generally poor health, showing little growth, poor leaf colour and few flowers. What's wrong?
A There are several potential reasons for the state of your tree; improving the growing conditions may help, or you may need to dig it up and replant elsewhere.
If your tree doesn’t get established, it won’t fruit. Try digging it up, soaking the rootball in a bucket of water if it seems dry, and replanting the tree, spreading the roots and firming it in well. If this doesn't work, replace the tree with a new one.
Improve growing conditions
Poor growing conditions could be to blame – not enough sun, water or food; or waterlogged or chalky soil. If you need to get more light on to the tree, prune adjacent trees. Aim to boost growth by clearing weeds and grass away from around the base of the tree to the full extent of the branches. Add 120g per sq m of growmore each spring to the cleared area. A thick mulch of organic matter may help too. Use bark, shredded prunings or leaf mould. Manure is a bit risky as it can be too much of a good thing, producing excess soft, sappy growth. However, it is worth trying in extreme cases. If the soil is waterlogged, you might keep your tree in better shape by replanting it on a mound. Water it well in any future dry weather.
If all else fails...
You may find plant a vigorous rootstock results in better growth. With apples, for example, try MM111 instead of MM106.
Q My old tree has lots of dead branches and just a few small fruits. What's wrong?
A Judicious pruning may revive your tree, but it is possible that it's simply reached the end of its life.
When to prune
Pruning can bring an old tree back into fruit production, but don't expect miracles. It may take several years to do the job. First get rid of thin, weak and crossing shoots. Pay special attention to cutting out branches that form at a narrow angle, and to those infected with canker. If the tree is too tall, cut out some of the upright branches to strong side branches. This will let in light and reduce height. Try taking out a few branches each year rather than all at once. Finally, cut out weak, old growth that has borne fruit already.
When to replace
Sadly, fruit trees reach the end of their useful lives after about 50 years. Replacement is the best option. Beware of specific orchard-replant disease, which inhibits the growth of new related trees planted in the same spot. The cause is unknown, but is probably due to the newly planted tree being infected by organisms left behind by the old one. Either plant in a new spot, or with a different genus of tree. Stone fruit may safely follow pip fruit like apples or pears, but like should not follow like. Pip fruit may also follow stone fruit – cherries or plums, for example.
Q My tree seems healthy but produces no flowers. Why?
A There are a number of possible reasons for this. Younger trees Maybe your tree is just too young. It could also be that it has been grown on a vigorous rootstock and these normally start to fruit later than more dwarfing types. Prune to get the shape you require and, in time, it will flower. Self-sown seedlings These often fail to produce fruit. Self-sown seedlings have a long 'juvenile' phase before they flower. The process of grafting, which is used to produce commercial trees overcomes this, to some extent. However, plums and peaches generally produce fruitful seedlings if you can wait. Other seedling fruits seldom crop as well or produce as good-quality fruit as the named kinds.
Q My otherwise healthy tree produces only a few flowers. Why is this?
A Check your pruning; you may be suppressing flowers by pruning incorrectly. Heavy pruning in winter will often induce vigorous shoots that don’t flower well.
Occasionally the cause will be birds eating buds. Bullfinches are the master criminals but tits, chaffinches, greenfinches and sparrows are also culprits. Fruit may be stripped of their dormant buds in cold weather. Ideally, grow fruit in a cage which can be covered with netting before winter. Later, this will help protect the ripening fruit.
However, this can be costly and is not practical for large trees, though you could just net a few branches. Visual deterrents are the only alternative. Birds get used to them, so they should be changed and moved frequently.
Your tree may be a 'biennial bearer'. Some varieties are particularly prone to this, and any variety may have a poor year after a good one. You can reduce biennial bearing to some extent by thinning the crop. Where you can, thinning is generally beneficial as it encourages larger, sweeter, richer-coloured and better-shaped fruit, and reduces the risk of branches being overladen and damaged.
The timing of thinning is a controversial topic. Traditionally, it was left until after the June drop when the tree naturally thins itself. However, by this time the tree has already used energy on the half-developed fruit, and it is also too late to affect the following year’s crop seriously.
Some farmers routinely thin the blossom, usually by spraying, but this is a bit risky. If the fruit set that year is poor, then the overall crop will suffer. A good compromise is to thin as soon as the fruit it set.
With apple and pear trees, aim to leave one fruit per 15cm, discarding any imperfect or diseased fruitlets first, as well as the biggest fruit in the centre of clusters of fruit. Where spurs are supporting masses of fruitlets, aim to leave one fruitlet per spur. Thin plums to one fruit per 7.5cm. Also reduce the amount of fruit on thin branches that might snap under the weight of a heavy crop.
Many interesting old fruit varieties are unreliable croppers – one reason why they get superseded. Other varieties well known from the shops (e.g. 'Granny Smith' apples) are unreliable in our climate. The solution is to replant with a more reliable variety. Apple varieties 'Discovery' and 'Falstaff', for example, seldom fail to crop.
Q There are plenty of flowers, but no fruit. Why?
A The two most common reasons why flowers fail to produce fruit are frost damage and lack of pollination partners.
Pollination and fruit-set are very sensitive to cold springs. This is probably the main reason for the enormous variations in crop from year to year. Frosts are extremely damaging to the buds, blossom and young fruits. Late April and May frosts are common causes of poor or absent fruiting. The remedy is to grow fruit only on sites where frost is less of a problem.
Avoid low-lying districts, northern areas and valleys. If you live on a hillside, help frosty air escape by making sure there are gaps in hedges and fences on the downhill side. Also, deflect frost travelling downhill by positioning hedges uphill of your fruit.
If your trees are small enough, cover them with old curtains or fleece on frosty nights. More practically, go for late-flowering fruit. Apples flower latest and plums and cherries earliest.
Bees and other insects are essential for pollination. Windy and cold weather reduces their effectiveness, leading to a poor fruit set. Help them by growing tall hedges around the fruit garden to reduce wind speed.
Most fruit trees are not self-fertile and give a poor crop without one or more pollinating partners. Even self-fertile types, such as 'Conference' pears and 'Victoria' plums, crop better when they are pollinated.
Aim to grow trees that flower at the same as each other or as those in neighbours' gardens. Ornamental crab-apple varieties are excellent apple pollinators and take up little space. 'Golden Hornet', for example, is a space-efficient pollinator.
Traditional varieties of sweet cherry require pollination partners, and this can be quite tricky as many pairs are not compatible. However, there is now a choice of modern, self-fertile varieties including Lapins, 'Stella' and 'Sunburst'. The acid cherry 'Morello- is also self-fertile.