I have noticed, in my limited experience, that my apple trees will set terminal buds for a few weeks, then the buds will break and another round of growth will ensue. I have too much water, and my trees are planted across a drainage gradient going from decent drainage to very poor drainage. I suspect it is heat related here. I will keep an eye out this week. We have 95+ degrees with possible dew points of 80 degrees in the forecast.
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Iām going to keep them watered and hopefully they will give me another surge soon. I have several one and two leaf trees that Iām trying to get up to size quickly.
That is my understanding, mostly from reading, and a little from experience, that apple trees have a main spring flush of growth, then take a break, and then generally put on a second flush of growth later in the summer.
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The spring flush is probably at least 80% of apple tree expansion here. Shoots resurge for some added length, although it is hard to gage how much this has to do with leaf hoppers completing their cycle here- E plums get a late mini-surge as well. Growth certainly stops when they suck the life out of growing tips, which they usually do by mid-summer if you donāt keep poison on them.
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Donāt forget the factor of stored energy. The basic premise I keep reading is that most of the growth flush comes from sugars/nutrients stored in limbs, and once you exhaust that your growth slows way down while the plant gathers more. I have been trying to encourage a second/continual growth of my small trees with foliar feeding and liquid nutrients. Very small sample size but it does seem to be working, although CAR has been a little rough on some of the trees this year.
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I havenāt used a foliage spray but I started adding a liquid fertilizer about the time I noticed the slowdown. This morning I noticed two limbs starting to grow again. We normally donāt get any freezing temperatures until about mid November so there is ample time for new growth and hardening off for the winter.
Water and fertilizer will keep the trees growing. Let apples get dry just for a short period and they often set terminal buds. After that they can be hard to get growing again. Young trees are easier to keep growing. I can see the advantage of extra growth on young trees. But on older trees I generally donāt want that much growth so am happy when they quit.
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That is not my understanding. I believe that a couple weeks after the establishment of canopy, the tree has a surplus from energy being produced and a lot of that energy gets pulled forward to make new wood. Give me a link to what you are reading- maybe my understanding is outdated.
After writing the first paragraph I found this. http://www.hort.cornell.edu/expo/proceedings/2014/Tree%20Fruit/Apple%20Productivity%20Lakso.pdf
Last years energy for apples seems to be used up by around bloom if this paper is correct.
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I stand corrected, although that link does make me think the foliar feeding might be extra effective for distance, as I donāt mind whip like growth trying to fill up my fence wires.
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I just finished reading the article I linked to and it probably confirms what might be my own theory- that spring pruning of vegetative shoots is the best way for those of in more northern, short season areas to assure annual yields. Summer pruning is useless for this because it is spur leaves that gather the important energy for fruit and buds for next years flowers. If they are shaded out in spring their capacity to photosynthesize is destroyed for the season, so summer pruning of vegetative shoots can be worse than useless- actually reducing fruit size and probably sugar because they are the only source of carbs for the fruit at that point- spur leaves cannot be brought back into carb production after being shaded through spring.
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So itās counter-productive to summer prune for northerner?
As flattered as I was at first to read that, you know Iām not close to being experienced enough to know such things, so Iām guessing you are talking about another Kevinā¦but I didnāt know we had another one. Who is it?
Kevin aka Applenut.
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Ah, I see Muddy beat me to it. Another great Kevin, Kevin Hauser. He runs Kuffel Creek Apple Nursery here in S. California, in the Inland Empire. He is a frequent contributor and probably knows more about growing apples in low-chill than anyone else out there.
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Iāve long been a fan of Applenut and his obvious expertise via posts here, but somehow missed that his name was Kevin. Thanks both of you for alleviating my curiousity
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That depends on whether the shade created by shoots has made the more interior leaves dysfunctional Summer pruning reduces summer diseases and also reduces the amount of pruning that needs to be done in the winter considerably. I spend much of summer pruning many apple trees along with plums peaches and pears as much as for any other reason, just so I wonāt have more than I can do in spring and early summer. The trees get big, sweet fruit, perhaps because they are open enough to begin with to keep spur leaves working.
Commercial orchardists arenāt advised (yet) to do spring pruning. They solve the problem by keeping trees very open to begin with.
Iāve read and re-read.
Iāve learned and kept absorbing but also forgettingā¦ Things that were discussed by this boardās experts but somehow escaped my retention bag! Old age already crept in!
Thank you for this discussion.
Tom
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