North American Fruit Explorers mailing list at ibiblio

[Alan Haigh <alandhaigh@gmail.com>]

Water sprouts can be wiped out any time and for the most part you can prune
any season if you understand what you want and how trees respond.

In spring, trees have not refilled the bank as far as energy reserves are
concerned so pruning is bound to be more dwarfing- also terminal buds don't
set until mid-summer so regrowth will occur for sure.

Too much pruning before mid-summer and even after can have an adverse
affect on the quality of the fruit- but there are so many variables here it
is difficult to get a handle on exactly what are the parameters.  Summer
pruning can also improve the quality of fruit by getting light where you
need it- when it hurts is when you make fruit watery as foliage can steer
water and N away from the fruit to some degree as it ripens increasing the
concentration of sugar in the fruit.

Of all species, I prune peaches most during the growing season and have
found that a complete pruning after harvest seems to put energy in the
shoots that will give me fruit the following year.  Getting light on new
wood is very important for peaches- especially with non irrigated trees and
letting light in to where you want to harvest your peaches will keep them
productive for a much longer time than if the productive part of the tree
is excessively shaded.

Summer pruning of cherries and J. plums can be useful if you stub branches
back several times starting at bloom (in spring), always favoring a shoot
to keep the branch heading out straight while pinching back those to be the
subservient, fruit bearing wood.

I usually cut out interior vegetative growth in apples- especially vigorous
old trees- unless we have an early spring like last year and I'm trying to
hold back ripening of the fruit as long as possible- no way I did any
summer pruning of Macintosh, Honeycrisp or any other varieties that have
lousy quality and drop early in long warm seasons.  Unfortunately that
wasn't enough to assure quality last year here in southeastern NY because
spring arrived at least 3 weeks early.  This spring it's the opposite.