Fewer and fewer blossoms on apple trees

[Jbest]

I have five semi-dwarf apple trees about forty years old. The last several years they have been producing fewer and fewer blossoms. Do semi-dwarf apple trees have an expected production life expectancy or do I have a problem. The trees look healthy and the weather is not much different from many other years.

John

[MaineDesigner]

What have you been using for fertilizer? After that length of time it is very possible that some nutrients, especially trace elements, have been depleted. Have you had any soil testing done?

My understanding from conversations with commercial orchard owners is that you are in the range of what is considered the effective life of dwarf and semi-dwarf trees but decisions in commercial operations are also influenced by changing market preferences so there may be more to their thinking than just productivity issues.

[The Helpful Gardener]

How much hard pruning, have you done, John? These plants really do like a good hard cut; it's why you see orchard folk whacking them back in late winter. Hard pruning can rejuvenate many fruit trees; I brought back an old pear in MIL's yard with one really good whacking...

HG

[Jbest]

I fertilize them with 5-10-10 and I prune them religiously very early spring. Here is a photo either late Feb. or early Mar.
John
[img]https://www.jbest123.thegardenjournals.org/wp-content/uploads/2009/03/p3070064.jpg[/img]

[The Helpful Gardener]

I like your pruning job for the most part John, but it's not what I'd call a hard prune. Have you seen what the pro orchard guys do in February-March? Hardly anything you'd call a branch, right down to nubs. These trees are getting on and some rejuvenation pruning seems in order...

(Finally my tax dollars are working for me)

[url]https://www.ct.gov/dep/cwp/view.asp?A=2723&Q=325958[/url]

That 5-10-10 doesn't sound organic. Could be you have depleted the soil biology that was supporting the tree (things like mycorrhizal fungii are very important to nutrient uptake). Perhaps an leaf mold/bark/ chip/compost around the roots might help things along and add vigor to old trees? I have seen air spading and soil replacement with biologically active soils turn trees around on a dime, but I don't think we need go that far... just getting some biology back into the rhizosphere sounds like a great idea... Bradfield Organics has a 5-5-5 organic (that is plant based so it will stay around in the soil instead of wash away) that will feed even better than chemical 5-10-10, and it won't kill mycorrhizae...

HG

HG

HG

[Jbest]

Scott thanks for the information and link. I think my soil is ok, this time of year there is a pile of worm casing every square inch of my property. I have seen the commercial pruning and thought they were just trying to limit the number of apples to increase the grade. People say that a willow tree grows fast but the willows cannot compete with an apple. I remove two full 4X8 utility trailer loads of branches every year and when I do a hard prune, I will probably have three loads.

How soon after they go dormant can I prune? Our December weather is always nicer than our February weather.

I have free access to well aged horse bedding compost and was thinking of mulching out to the drip line with about 4â€

[The Helpful Gardener]

I like the mulching idea, John. And the hard prune, but really wait until later. I do see some allowances for late fall pruning, but every orchard I know does it in February/March, and I just trust old pros. Even right before bloom would work, but leaving open wounds all winter with the freeze thaw; I just think you are better off waiting...

HG

[MaineDesigner]

I second Scott's recommendation. Most of the apple orchard work here in northern New England, where spring arrivals glacially slowly, is done between mid to late February and early April.

[applestar]

I have this Enterprise apple tree that I'd basically given up on -- hadn't pruned or done much with it in years. Last year, I decided I was going to REALLY take care of it. Did a lot of reading. So this is just an account of what I did rather than a recommendation:

Based on what I read, I decided it was OK to begin with a "late summer/early fall" pruning -- Enough time for the scars to heal, but no later than Labor Day, some books said.

Well, I actually didn't get to prune until Sept 16 and cut away the "dead, broken, and crossing" branches as well as some badly placed ones. We didn't have much of an early warning frost, but had a hard freeze on Oct 2.

Then the urge hit me again -- to limit growth the tree had to be pruned BEFORE winter and some sources talked about late fall pruning (late winter/early spring pruning stimulates growth) -- so on Nov 2, deciding that they really had to go, lopped off a shooting leader as well as 1/4 of branches here and there, leaving a little extra to provide for winter die-back. (We were having a relatively mild late fall -- I didn't put my Venus Fly Traps inside until Nov. 17 -- after a couple of good freezes)

Dec 29, mulched to drip line with compost and straw for the winter (grass/weeds to the trunk until then) Also scattered sweet clover seeds all around the tree and on top of the mulch as well.

Mar 8, pruned again, another 1/3 here and there. This was a little bit late -- I think a local apple orchard pruned the week before, but I was trying to follow the injunction to "NEVER PRUNE FROZEN WOOD" (because without moving sap, the tree can't heal). Didn't notice much winter injuries from previous pruning.

I've no idea what helped most -- maybe I was just lucky -- but this spring, the tree was absolutely FULL of flowers. Now that the petals have mostly fallen, I'm going to spread some more compost over the straw mulch and spray with Surround (as soon as it stops raining for a while I tried spraying with diluted milk because I got worried about disease with daily rain since Saturday -- 1/2 hr after I came back inside, we had a downpour! )

[The Helpful Gardener]

Kaolin and milk; I like your orchard practice, Applestar. I see where you get your name from...
Interesting take on the fall vs. winter prune, AS; where did you come by this info? I should like to do some reading on that...

HG

[applestar]

Thanks "kaolin and milk" -- sounds like a facial product...

OK, WHERE did I get my ideas from??? At this point, I'm not sure if I can pin point the source -- I read from all over, books and internet -- I really should take better notes... but I'll try.
A lot of the sources that talked about late Fall, etc. I think the authors were from milder climates like California, England, France. I was a bit hesitant, but I really thought the leader and some other branches had to go. Also, I decided to espalier some of the newly purchased fruit trees, so summer pruning was another technique I was working from.

Books:
The Pruning Book by Lee Reich
OK, I think the critical reference is in pp. 25~26 excerpts:

How a plant responds to pruning depends not only on how much you cut off a stem, but also on when you do it. ... stored food also fuels the growth of the following season's new shoots and leaves... When you prune a dormant plant, you remove buds that would have grown into shoots or flowers ... food reserves ... are reapportioned ... to support growth of more buds ... with increased vigor.... As the growing season progresses, response to pruning changes ... later in the growing season ... Under certain conditions, summer pruning ... can prompt the formation of flower ubds rather than new shoots... Although immediate regrowth rarely occurs after late summer or autumn pruning, cells right at the cut come alive to close off the wound. Active cells are liable to be injured by cold weather... avoid pruning in late summer or autumn except in climates with mild winters or with plants that are very hardy to cold.

Also mentions no late spring or early summer pruning of apples in fire blight prone areas.

Pruning Made Easy by Lewis Hill
This might've been th one that said "no later than Labor Day"... Hmm or it might've been one of the old Organic Gardening mag articles.... (I hope I'm not confused about that because I can't find it in my notes Oh, wait, I found it -- "One reference emphatically recommends against pruning after Labor Day because the trees will expend their energy into growing new shoots which will not be winter hardy and in all probability will be winter-killed." -- doesn't say where it came from though. )
On p. 26 there's a box discussing when to prune. You can see it on Amazon's look inside if you search for "when to prune" https://www.amazon.com/Pruning-Made-Easy-everything-Illustrated/dp/1580170064#reader

Late Summer Pruning... The tree will be stimulated to set more flower and fruit buds and fewer branch and leaf buds the following year. By removing branches in late summer, you will cause far less regrowth than you would in late winter.

Success with Oganic Fruit by Yvonne Cuthbertson
Describes "late autumn to early spring" pruning of apple trees.

Edible Landscaping by Rosalind Creasy

American Hroticultural Society Pruning & Training
I notice I went out and did the November pruning after reading this book, but I don't have notes on why. I found a page of notes started for this book that abruptly ends. I have the feeling I dropped everything and went out and pruned...

ON-LINE: don't know what's what but here are some links I saved

DEP: Rejuvenating Apple Trees Fact Sheet
https://www.ct.gov/dep/cwp/view.asp?A=2723&Q=325958
University of Delaware Cooperative Extension, Kent Co., Commercial Horticulture Information: Landscape - Pruning
https://kentcoopextension.blogspot.com/2008/01/landscape-pruning.html
Training and Pruning Fruit Trees
https://www.ces.ncsu.edu/depts/hort/hil/ag29.html

Dormant Pruning vs. Summer Pruning

Trees respond very differently to dormant and summer pruning. Dormant pruning is an invigorating process. During the fall, energy is stored primarily in the trunk and root system to support the top portion of the tree. If a large portion of the tree is removed during the winter, while the tree is dormant, the tree's energy reserve is unchanged. In the spring, the tree responds by producing many new vigorous, upright shoots, called water sprouts, which shade the tree and inhibit proper development. Heavy dormant pruning also promotes excessive vegetative vigor, which uses much of the tree's energy, leaving little for fruit growth and development.

Historically, much of the vigorous, upright vegetative growth has been removed during the dormant season; heavy dormant pruning results in a yearly cycle with excessive vegetative growth and little or no fruit production.

Timing of dormant pruning is critical. Pruning should begin as late in the winter as possible to avoid winter injury. Apple and pecan trees should be pruned first, followed by cherry, peach, and plum trees. A good rule to follow is to prune the latest blooming trees first and the earliest blooming last. Another factor to consider is tree age. Within a particular fruit type, the oldest trees should be pruned first. Younger trees are more prone to winter injury from early pruning.

Summer pruning eliminates an energy or food producing portion of the tree and results in reduced tree growth. Pruning can begin as soon as the buds start to grow, but it is generally started after vegetative growth is several inches long. For most purposes, summer pruning should be limited to removing the upright and vigorous current season's growth; only thinning cuts should be used. To minimize the potential for winter injury, summer pruning should not be done after the end of July.

This is where it get's confusing "not ... after the end of July" -- but this is from North Carolina. I've noticed you REALLY have to pay attention to the geographical location of the author. I think that's why I settled on Reich's book as my main timing guide. But maybe this quote provides a clue to jbest's problem?

A LOT more links on espalier, but I don't suppose you want to wade through all that. I think there are others, but that's all I can think of right now.

[The Helpful Gardener]

Alright already; I didn't say I needed reading material for the rest of the year!

Thank you AS. Very thorough; I shall be a while wading through this, but it seems the pronouncements against summer pruning refer to soft growth, not late fall pruning. I can see your point, but if we are waiting until after frost, the dormancy trigger has been pulled already and new growth is unlikely, right?

HG

[applestar]

Right. That was my thinking too. Late fall, AFTER the tree had gone "dormant". AND, since "winter injury" occurs when sap is not flowing but some movement is still there before full frozen winter sets in, I thought it might be OK in Nov. and as it turned out, I had about 2~3 wks grace before the freeze set in. Also, I cut 2 or 3 buds longer than where I wanted in case the end buds died, so I could choose the live bud to prune to at the late winter/early spring pruning.

Have fun reading!

[The Helpful Gardener]

Right, in many ways late fall is close to late winter, as far as tree cycles are concerned...

I'lll read; we'll talk

HG