cherry tree

You used to be able to buy winter wash for fruit trees that contained tar oils, but it is banned now as it was carcinogenic.  It went at the same time as creosote and all those products.

The new winter washes now contain plant oils, soaps and the like.  The idea is that they kill overwintering bugs and eggs, but they are not the cure all you might be expecting. 

What problems are you trying to solve?

By the time I'd tried to deal with aphids, curly leaves, lack of pollinating insects necessitating pollination by hand, trying to net over the two cherry trees in a way that was bird-proof, and only having one worthwhile crop in eight years, I finally found the solution to all of these problems.   I got my husband to cut them down and dig them out. Problem solved!
Now I have space for a couple of really nice pear trees that will give us fresh fruit and enough to bottle with little or no trouble.

Fruit dropping or drying up could be due to the aphids, or lack of water or nutrition. 

You could try a winter wash just to make sure you clear the tree of aphid eggs, but I think a regular spraying regime from bud burst will still be needed.  Soap spray is fine, but don't leave it until you see curly leaves.  Soak the tree with suds on a weekly basis from the get go.

If the tree is in the soil, a good winter mulch of rotted manure or compost will help feed the soil and make it less prone to drying out, just don't pile it against the trunk. Its a job I do over the winter with all my fruit - tree fruit and soft fruit.

If it is in a pot, you could top dress it or maybe move it up into a bigger pot. 

A handful or two of extra fertiliser next spring might be a good idea.  My fruit trees and bushes get chicken manure pellets as a boost, but I think the mulching is the key 

May I ask what mixture you use for the soap spraying & what type of soap Please .

Thanks

John

A small squeeze of washing up liquid in a spray bottle of water will knock down green and black aphids but not much more.  You can buy sprays that have oils included that cling better.  Soap works by clogging up the air holes insects breathe through, so if you are trying to get wooly aphid or something similar, it might be worth buying the heavier duty product.