I have three sour cherry trees on dwarfing rootstocks, here is one of them:
All three have been devastated by aphids in previous years. Organic pesticides did not work. They have long spindly branches with a few leaves at the end. Can I prune them to improve the shape? Maybe cut back the branches, and hope they survive to next year with no leaves?
Welcome to the site Leif,
I would advise as follows, your tree needs to use those leaf’s to feed its root system and regain health after the aphid attack. I had a peach tree that went thru a similar devastation with plc, and eventually after watering it well thru this dry weather it has fully recovered and now I simply need to do a better job this fall and spring before bud swell to fight the PLC! You are in a similar situation, taking away the photosynthesis ability of your tree is not a good time to do! Especially since it’s trying its best to recover! Better to extend your woodchip mulch to about 6” to a foot beyond the drip line so the feeder roots can be kept in moist fertile soil to assist a faster recovery. If you can locate an older pile of hardwood chips to build up about 6” thick mulch layer around your trees starting about 4-6” away from the trunk, with only a couple inches near the trunk, that will help your tree thru the growing season. Water it 2-3 times weekly during dry spells. Wait until spring to do any pruning. By then the tree will have enough stored energy to respond well. You can search for @joereal remedy for fighting aphids this fall and next spring! Best wishes
Dennis
Kent, wa
If the aphids are black ones and the leaves are curling, those aphids need ants to move them around. Just put some pine tar on the trunk all the way around and the ants won’t be able to get into the tree any more. My cherries get devastated by aphids if I don’t do this. If you don’t see any ants with the aphids this will not help you unfortunately.
Thank you. I realise the leaves feed the tree, but my worry was pruning outside summer and the risk of Chondrostereum purpureum, I think that is silverleaf disease in English. I have already mulched, and do so each year with rotted farmyard manure, though there is a limit to the depth I can do. Should I prune just before it ends dormancy then?
You could be right. I put ant powder round the base of my blackcurrants to prevent aphids, it works.
Yes, just disinfect all pruning devices before use, should prevent infections
Dennis
Thank you, I will do that.
