Location: Western WA, Olympic Peninsula, USDA Zone: 8b
posted 3 years ago
As mentioned above, it will depend upon what you are trying to accomplish with the tree. If your goal is to maintain a fruit tree at a certain height (usually smaller or more easily manageable) then summer pruning is typically performed (mid or late June for example). If your goal is to encourage growth or new growth in the fruit tree, then traditional late winter/early spring pruning is preferred.
I've become a fan of late summer pruning after reading Ann Ralph's book "Grow a Little Fruit Tree" as well as Dave Wilson Nursery's "Backyard Orchard Culture".
I'm not going to pretend to understand it all. I understand the concepts, but putting them into practice seems a bit more difficult to say the least. Consider me the "measure twice, cut once" type lol. I'm probably more paranoid about pruning than I should be.
With that said, just yesterday the book I ordered on the subject arrived courtesy of Amazon. It's titled American Horticultural Society Pruning and Training. It's currently priced at $16.
From the small amount I browsed earlier it's WELL worth the money. Its rare I buy a reference/instructional book and don't wish I just got the info for free off the internet, this book I would have gladly paid double for. It covers the concepts behind pruning, the basics, and how to guides for everything from topiaries, ornamentals, shrubs, and fruit trees. Shows how to train for various shapes (cordon, fan, espalier, etc.) with year to year instructions as well as explaining why to use certain forms and which trees do better with certain forms. Hell, it even covers the different rootstocks normally used for fruit trees. Even included a breakdown of popular trees: normal form, common desirable forms, habitat preferences, zone rating.
Basically, this is the book I've been looking for on pruning, and I can highly recommend it for no other reason than having a handy reference. May be something you want to check out
I would suggest Fall for general pruning on apple and pear in Western Washington - pick a day after dormancy - Nov/Dec, not freezing and dry. Disinfect the pruners between trees with alcohol or bleach. Try not to overdo it: remove some damaged or diseased wood and thin some crowded areas or branches at odd angles.
If you have large branch pruning or topping branches over 3" diameter to do, I would wait until a dry time in June/July to prevent disease and discourage sprouting regrowth.