Spring prune while you thin

The best results from thinning occur when it is done from a week to 3 weeks after petal fall for any given species or variety. Later thinning won’t help apples produce next years flowers much (prevent biennial bearing) and won’t improve the overall quality of any fruit as much as earlier thinning- partially because size increase is created by cell division during early fruit development while later thinning primarily increases individual cell size, whether stone fruit or pomes. More cell density= more flavor. Serve early fruit growth well, then, if you can, discourage vigor later. If nature doesn’t rain on your parade you can use the spigot and keep watering to a minimum during the last 45 days of ripening or so.

I have been doing a great deal of thinning for the last week, starting immediately after my 1st insecticide app which I time with last apples that lose their petals for all the fruit we grow. One thing I think is important with vigorous, free-standing trees is to prune as you thin to make sure a lot of light reaches the leaves near the fruit. This means brushing off watersprouts forming on big wood with apples and pears, but also selectively cutting crowding branches that looked alright before leaf-out. Also any stonefruit shoots without fruit, or any growth that isn’t serving well-lit fruit in general. Every medium sized peach or apple needs about 30 leaves serving it to reach max quality, and that is what most home-growers are shooting for.

If you are worried about fruit being damaged after initial thinning you can thin the fruit to half the desired distance your first time through- say to 4" apart for peaches. I think the results will be as good for the eventual harvested fruit, although I have no data on how much energy fruit sucks at which stages of development. Incidentally smaller fruit is proportionately spaced closer. My first go-through for plums I tend only to remove all touching fruit, especially E-plums.

I’ve stated on this forum many times that excessively shaded leaves permanently lose their ability to harvest light, even when summer pruning opens things up for them. Whence the increased value of judicious spring pruning while you thin. This is especially true in typical home orchards that don’t get dawn to dusk sun exposure.



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