Cherry trees not looking good

[Leif]

I have three dwarf sour cherry trees and they all look pathetic with spindly branches and a few leaves at the end of the branches. They suffered horrendous aphid attacks in previous years. I first used an organic insecticide which was useless, then in the next year one based on Pyrethrum which worked. Here are two of the trees:

Can these trees be rescued? If so, how?

As an aside I have little luck with fruit trees: a cordon plum that grows incredibly fast like a plum on its own rootstock, a dwarf quince that is over 6m tall, and medlars that fall over. At least a recent plum, quince and medlar are doing well.

 

[MoreRootsMoreFruits]

interesting. i've got one planted in a container since last year but nothing much of blossom yet. is there any need for those lower branches below the fork in the main stem. just wondering if you could get some cuttings for more trees out of them and let the higher branches gain from a bigger share of available resources. ever considered liquid silicon rather than topical treatments? the general idea is it thickens a plant's cell walls so might make it harder for things like aphids and bacteria and weathering to penetrate/damage

 

[MoreRootsMoreFruits]

just read another post about pruning vines/fruit trees that recommends generally limiting pruning to about a maximum of twenty to thirty percent for shock avoidance. something to consider