The GARDENA gardening expert
Dear Ms. S., this is an unusual problem, because – as you have already correctly assumed – fruit trees generally begin to yield fruit after approximately three years.
So why is that not the case for your trees? I don’t know what tree form you have planted, but in general half-standard and standard trees bear fruit later than bush forms.
This is in particular the case if they have been grafted onto seedling rootstocks. These are “fruit tree roots” gained from seeds.
They guarantee that the trees live for a particularly long time, but also cause the tree to product a good yield later on. However, after eight years this should have occurred!
One human error when planting may lead to such a problem – planting the tree too deep into the ground.
The grafting position, a thickened “nub” over the roots, must always be located above the soil surface on fruit trees. If it ends up in the earth, certain growth mechanisms intervene, meaning that the plant produces leaves but not flowers and fruit.
Ground densification, waterlogging and unsuitable locations can also cause poor production of flowers and fruit.
If your trees flower but do not bear fruit, the problem could also be poor pollination of the trees. It is generally sufficient if an appropriate pollinator is based within a 100 metre vicinity of the fruit trees.
The bees will do the rest. However, not just the species of fruit, but also the variety must be correct.
Why exactly the problem occurs in your case can only be determined through an inspection of the varieties. If you still know their names, please send them to me. Then I will see if I can observe any conspicuous features, and respond without delay.