Fruit Tree Troubleshooting

Having planted and pampered stone fruit trees and then not being able to harvest their sweet fruit by the bushel full in late summer is disheartening. Why do they sometimes give so little, or even no fruit? Let’s do some fruit tree troubleshooting!

Stone fruit, including plums, peaches, nectarines, apricots and cherries, are deciduous in winter, covered in magnificent blossoms in early spring, and present their juicy fruit in a relatively short time from November to March – a wonder of nature to please the human palette!

Although these fruit trees are easy to grow, they can sometimes have a neurotic side to them refusing a gardener the gift of their fruit. Apart from a little impatience (most need 3 – 5 years to bear well), the following can be the cause of non-fruiting:

Position

Fruit trees need full sun exposure to set fruit. When planted where there is too much shade or if too close to a building, they will not fruit well.

Climate

Winter conditions such as harsh and cold winds we experience in some years and heavy late frost in early spring when fruit trees start blossoming, can cause damage such as bud-dropping – something a gardener cannot do much about, except for planting them in a protected spot or to temporarily covering them with horticultural fleece if frost is predicted.

Pollinating

Unlike yonder years, most of the modern stone fruit cultivars are self-fertile and need no cross-pollination from different varieties, but the bees and other pollinators have to do their pollinating job when the trees are in blossom. In a garden where lots of broad spectrum insecticides are sprayed around injudiciously, the friendly and handy insects will be killed off too.

Over-fertilising

Seeing as fruit trees can be so ornamental and fast-growing and space is at a premium in small gardens, they are often planted as double-purpose specimen trees in small lawns. Since lawns need regular fertiliser with a high nitrogen content to green them up, much of it with the regular watering needed, reaches the root system of the fruit tree which will then result in lush wood and foliage growth rather than expending energy into blossom and fruit production.

Over-pruning and under-pruning

Pruning any plant will stimulate new and wayward growth. Simply topping a fruit tree across its crown, or cutting back all the side branches without creating an open framework where the sun can reach and fresh air circulation too, will not work. Not finding out how some stone fruit should be pruned correctly, will not work either and will only result in more leaves and weak branches. Peach trees for instance need judicial pruning as the fruit is produced on the tips of the previous season’s growth.

READ MORE: Learn about fruit trees and cross-pollination here!

Pruning fruit trees

Your quest is a two year training programme for young, newly planted trees. For old trees not performing, the same principal works if they are cut back severely and then undergo training.

First year:
After planting, cut the central leader (main stem) back to just above the top side leader (side branch) you have chosen to remain. Shorten the other chosen side leaders you wish to remain to form an urn shape, by a third. Remove all other side branches completely (good fruit tree suppliers will perhaps have already done this).

Second year:
In the following winter you should remove all weakly developed wood and thin branches too close together or crossing each other, keeping the shape and direction of strong side leaders in mind. Prune those back by half to a bud facing sideways or downwards.

Following years:
Keep on shaping the open urn-shape by removing diseased and dying old wood and crossing branches pointing inwards.

Note:
Pruning this way will give you a tree with a high yield of quality fruit while the height and spread of the tree is controlled to make harvesting easier.

What do to with old trees

If you have old neglected trees not bearing well anymore, rejuvenate them by pruning them back very hard to about one meter high and start training them as described the following year.

Thinning out the fruit
It sounds strange to discard some fruit on purpose, but not thinning out some fruit on time (about 3 weeks after blooming time) a heavy crop load will reduce shoot growth leaving the tree with shorter shoots producing less flowers in the following season. Thinning out will also ensure the development of bigger, better quality fruit.

When the fruitflies got there first
Fruitflies cause great damage to fruit, making all the hard work to grow one’s own undone due to rotting and decay. The initial damage is caused by the adult fly when the fruit’s skin is pierced as it deposits its eggs and soon it would be crawling with maggots. Infestations occur all year round, but peaks from January to March on fruit trees such as peaches, quince, plums, and apricots. Methods of control include biological traps baited with sex pheromones to attract the males. Cultural practices to combat the fruitfly population are good garden hygiene, by removing infested and dropped fruit and by burying them deeply. Never add them to a compost heap. Another way to try and curb the problem, is to plant early season varieties of fruit trees ripening from early November to late December.

Good tip: Expose the ‘goggas’ by digging the soil around your deciduous fruit trees over about two to three times during winter to expose any overwintering insects and fungi spores to frost.

A maintenance calendar to encourage fruiting

June: At the end of June start pruning. Spray the trees afterwards with an organic fungicide to kill off overwintering pests.

July: Plant new fruit trees in well-prepared holes enriched with compost, bonemeal and a slow-releasing fertiliser for fruit and flowers. Spray existing pruned trees again with fungicide.

August: Feed all existing fruit trees along their driplines with a slow-releasing fertiliser for fruit and flowers and mulch with compost. Water deeply afterwards.

September: At about 75% of blossom drop start putting out baiting traps for fruitfly. As soon as fruit has started forming, thin out heavily laden branches when they are about 5mm in size.

October: Keep on baiting and spraying against fruit fly. At the end of the month, feed again. Keep on watering deeply.

February: Fertilise again, and do light summer pruning to remove wayward growth and to allow in more light. Remove any water shoots and suckers perhaps sprouting from the rootstock. Fruit tree cultivars are mostly grafted on a vigorous, different tree’s rootstock that has a bigger resistance to soil-born diseases. Allowing this rootstock to grow out can harm the wanted scion or graft.

April: Clean up fallen fruit around the tree and give a final feed of fertiliser. Renew the mulch and water well afterwards.

Learn from the past:
In small suburban fruit orchards there was no lawn planted around the trees. Their main trunks were surrounded by very neat soil basins spiffed up regularly with a spade. This was to stop the mud walls breaking when watering with a hosepipe. Nothing else grew under the food trees. Kids played under them and baked mud cookies.