No trick that I know of.

As long as the trees are healthy and you don't get a frost on the blossom, or it is too cold and wet for the pollenators to visit, or then so dry that the infant apples drop off, there should be apples. They do need to get some growth - they don't fruit in the first few years.

I have a compost bin which I fill up with kitchen waste and any plant material, and I put it alternately beside the two trees, so they get the benefit of the 'juices' once the bin is removed and the new soil spread about under the tree.

Some varieties of apple require pollen from another variety, as their own doesn't work for them. If there is no other tree nearby then a single tree can be a poor cropper - if the four you have are all the same sort that might be the problem. It is unusual for such trees to be planted alone, though.

They do better if they are pruned a little, cutting off the branches which grow straight up from the middle of the tree whilst they are still young is a good idea, best done about the same time the apples are picked - the tree needs to be kept open and spreading - overpruning is not good, reducing the tree to a pom pom 4 ft across will not do it any good at all.

You could just take your axe outside and sharpen it in a contemplative manner - that might encourage them.

Anne the Pleater :ootd: