Heavy Summer Pruning?

We recently set down some roots in the PNW and bought 10 acres including an apple orchard of about 300 dwarf trees (mostly M9 we think). The orchard has been well.. a bit let go as of late, as the 90 year old we purchased from was having problems keeping up with it all (although he did a great job right through his 80s). Now, nearly each tree is a different variety of apple (about 260 varieties). So there's an incredible diversity in pink, petal fall etc.

Many of the trees need a vigorous pruning and many have a fairly heavy fruit set it seems. I'm concerned primarily with the trellis system (falling over and domino-ing) and with the upcoming added weight I'm concerned that more rows will topple. Since the trees need the pruning anyway and from what I'm reading in Holistic Orchard - sounds like we could alleviate some of the extra weight during this summer dormancy period we are entering. Also we aren't blossom thinning this year - so could help out with fruit size it seems (though many of the apples will be sold to Alpenfire as hard cider so size isn't imperative).

We have very dry summers (as we're in the Rainshadow of the Olympic Mountains with about only 20" annually of rainfall). The winter is moist and we may benefit by avoiding disease by timing pruning this way theoretically. It was "organic" the past few seasons due to neglect mostly. We are scrambling with the tent cats (hand pruned the entire orchard 4x already) and with obtaining hay for mulching to begin with. Anyhow our time is limited this season (also have to figure out some sort of irrigation and there's that trellis problem), but do you think it would be a good use of our time to prune now or wait until winter?

Nick Segner

Wildcat Valley Farm
Zone 8b
Olympic Peninsula Rainshadow
Port Angeles, Washington



Edited 1 time(s). Last edit at 06/02/2014 08:37PM by Michael Phillips.

Nick, it sounds as though you have no option but to do some summer pruning, the question is "how much?" We find summer pruning can really reduce tree vigour, so it might be wise to go easy on the weaker trees.

In our environment, summer pruning up until the fruitlets are about 20mm diameter , or summer pruning two or three weeks before maturity (to help fruit colour) doesn't seem to have any adverse effect on fruit size, but summer pruning in mid summer really seems to upset our trees, and fruit size really suffers. We suppose this is due to changing the leaf to fruit ratio, and also suddenly reducing the sugar supply to the roots. A light prune in mid summer probably doesn't hurt, but we find the harder we prune in mid summer, the worse it is.

If the trees are on a dwarfing stock such as M9, you will need to be careful when trying to straighten up the ones leaning over, as they tend to be brittle and have a nasty habit of snapping off at the bud union, or just below ground level. Sometimes on trees leaning over badly, it is better to cut to a strong vertical shoot coming from the original (sloping) leader, and straighten the tree that way by establishing a new, replacement leader. Best done in winter, but maybe you will have to do some now.

Of course, we have a very different environment to yours, so some of what we have said here may not apply.

(Just wondering, what does "scrambling with the tent cats" mean?)

Kalangadoo Orchard
On the “other side” in South Australia



Edited 1 time(s). Last edit at 06/02/2014 07:36AM by Michelle & Chris McColl.

Michelle and Chris,

Thanks for the reply!

Yep, I don't want to prune too much so I do need to pace myself this season. Thanks for the info on the good windows for pruning. I will check with a couple local growers to get some local advice as well. Also - good idea about retraining central leaders on the flat-lying trees. There's a couple rows of Belle de Boskoop that are in this situation and since they are supposed to be vigorous trees they will probably come back well that way (I hope!).

Haha by "tent cats" I was talking about our current plague of tent caterpillars. They are all over all deciduous trees in the area the past couple years and last year their droppings coming down from the alder canopy where we were renting sounded like rain there were so many of them :/

Nick Segner

Wildcat Valley Farm
Zone 8b
Olympic Peninsula Rainshadow
Port Angeles, Washington