Partial Outer Canopy Defoliation on a Crab Apple?

[Novocastrian Greg]

Hi everyone, I hope this hasn't been discussed to death and thank you for reading. I have a Crab Apple which is in refinement. The trunk and primary/ secondary branches are all in place and i am looking to increase ramification and fill out the canopy a little. The tree is healthy and vigorous even after repotting this Spring.

I have seen conflicting information about defoliating crab apples. Some people seem to say that partial or even full defoliation is a good idea. Others seem to say that it is a bad idea and one should only cut the leaves in half. I have two questions. 1. From your experience what results have you had from partial/ full defoliation of crab apples? 2. What would be the purpose of cutting leaves in half: is it just to allow light to penetrate further into the tree?

For information. i'm in Australia in the temperate part of New South Wales, so it is late spring here. Our growing season begins late August and continues through to March with a dormant period in January.
Many thanks, Greg

 

[Shibui]

I don't think I have ever defoliated a crab apple. Just regular trimming to control vegetative growth and promote more and more fruiting spurs.
Cutting leaves in half is usually just to weaken the tree by removing some of the food factory and to let light into the interior. It does not usually trigger new shoots which you'll be wanting to increase ramification.
Removing the whole leaf is more likely to trigger new shoot growth.
Watch out for long internodes on vegetative shoots. Long bare sections is not good for ramification even if you can get new shoots from each node.

 

[Novocastrian Greg]

Thanks for that, Shibui. Much appreciated. I'm thinking i'll cut the leaves in half to limit photosynthesis but i won't defoliate, just cut back to two nodes.