I recently received this question from Wendy in Wisconsin,
I have a 15 yr. old sargent crab apple, multi-trunked, planted 6 ft. from the house, under a large window 8 ft. from the ground.
The hope was the tree wouldn’t grow beyond 8 ft. in height, but it’s now more like 10 ft.…Last year, because the tree had grown above the bottom of the window, I pruned the ends of all the top branches (i.e. shortened the tree)… This year there is vigorous new growth (3-4 ft., with multiple branches from a single cut) from all the cuts I made last year…
I’ve actually thought about removing the tree and replacing it with another young Sargent or a Sargent Tina and widening the borders of the bed to give the tree more room.
Do you have any other suggestions?
Did you know that pruning can actually cause a tree to grow more? Yep. Cutting branches off a tree can cause the tree to grow more in the future.
Some days it sure seems nothing is as simple as it should be in life!
Yes, you can actually cause your tree to get bigger through pruning it.
The reason is that the buds at the end of branches release hormones that limit how much other buds in the tree are allowed to grow. When those buds are removed through pruning, the other buds can grow like crazy.
So basically, whenever you are pruning a tree you are affecting its’ hormonal balance. Since they don’t make Midol or chocolate for trees, we will look at how the types of pruning cuts you make impacts tree regrowth.
Types of Pruning cuts
There are three types of pruning cuts that can be made. They impact how the trees respond in terms of suckers, water sprouts and shoot regrowth. The three types of cuts made are:
Heading cuts – Shortens the branch shoot, but makes the cut between lateral branches that grow off the shoot, or to a lateral that is less than 1/3 the diameter of the parent.
Thinning cuts – Removes the entire branch back to its point of origin.
Reduction cuts – Shortens the parent to a lateral that is at least 1/3 the thickness of the “parent” branch.
How different pruning cuts affect how the tree regrows
Heading back branches and especially the leader results in vigorous growth from buds just below the cut. The further back the branch is cut, the more numerous the number of shoots will usually be. If you just cut back some of this year’s growth, you usually won’t get a lot of regrowth. If you cut way back into previous year’s growth, then you are more likely to have problems with suckers, water sprouts, and huge growing shoots.
The regrowth after thinning cuts and reduction cuts are more widely dispersed throughout the tree. Individual shoots that grow are less vigorous than those from similar heading cuts.
Tip #1 – Only make reduction and thinning cuts
Crabapples are notorious for creating suckers, water sprouts, and just plain real long growth shoots after heavy pruning.
They are doing this for a few reasons.
Root to Leaf Balance
One reason is that they are trying to rebalance the amount of leaves that they have for their amount of roots. Tree’s roots and leaves are always in balance. When there are too many leaves and not enough roots, the leaves experience stress from not having enough water. The tree stops leaf and branch growth and directs its energy to growing its’ roots until the tree’s system is back in balance.
Likewise, when you prune a branch the tree loses leaves. It then grows a lot in order to regain the leaf to root balance.
So What Does This Mean For Pruning?
It is best to limit the amount of pruning you do. This will keep the tree’s leafs in balance with its roots. If you remove half of a tree’s branches, get ready for a furious regrowth especially on crabapples. You are best to limit your pruning to 25% of the tree’s branches. This will reduce the amount of suckers, water sprouts and real long shoots you get after the pruning.
Tip #2 – Shorten long sprouts & remove water sprouts and suckers completely
A good way to remove suckers and water sprouts is to snap them off from the trunk or branch they are growing off of right when they start growing in spring before they get woody and hard.
If you leave them you will get something similar to this:
Tip #3- Prune in early to mid-summer
The best time to prune a crabapple and not stimulate a ton of growth is in the summer after they are done with their large flush of spring growth. They just spent a lot of energy producing new branches and leaves and will not have enough reserves to grow back immediately.
Since crabapples form flower buds for next year in mid-summer, you ideally will want to do this before that time. If you don’t mind sacrificing a few flowers next year, mid-summer is also fine.
Tip #4 – Forget fertilizing
It is also important that no fertilizer is applied the year of or after heavy pruning. Nitrogen should not be applied because the root system under the tree is large enough to provide water, oxygen, and stored food reserves to all of the above ground portions of the tree before any cutting was done.
Crabapples are one of the most tolerant trees of heavy pruning. Crabapples are after all, really just an ornamental form of an apple tree. Apple trees in orchards are pruned in ways that would make your Sargent crab shake in fear like a plaque of Japanese beetles was coming. There is no reason to replace your tree if you are willing to spend the time pruning it a few times a year.
If you found this article helpful or have any other pruning related questions you would like me to cover in a future post, please comment below.
Sandra MacNevin says
Hi,
Are you still giving advice on crabapple trees? I have started pruning a 10 year old crabapple tree that has never been pruned, it looks like the picture you posted of the crabapple tree with all the suckers that looks more like a bush than a tree. Yesterday I cut away most of the suckers that were really thick, but there is one sucker that now grows off the side of the tree and is very, very thick in diameter, like a huge branch, and has grown as high as the main trunk and with huge branches in the canopy. Does that need to be cut also? The bottom part of that sucker tree grows out of the tree, touching it. So I am reluctant to cut it, and would need a heavier tool perhaps. Also, there might not be much left of the main tree’s branches. I am retired and can’t really afford to hire a specialist, but if I have to I guess I can try to find a retired person who will charge me less than the tree companies. I am trying to save and shape this tree back to health and beauty by myself with lots of advice! I watched your videos and read your website before I started my pruning yesterday. I will leave the water sprout branches until winter when I can better see the shape of the tree, but for now, I am working at the bottom with the huge 10 year old sucker trees. All are cut off now, except that one I mentioned above. Thanks for any advice you can provide.
Angela Waterford says
I wasn’t aware that trimming a tree down can cause it to grow more in the future. I’m going to enter a horticulture contest next year, and since my sycamore tree looks kind of overgrown in some parts, I plan to make sure that it grows more in those sparse areas in time for the contest and reduce the growth in the overgrown ones. Perhaps I can hire a service to professionally trim down my tree so I can make sure that I’ll get the result that I want.
Jim says
My pruning experiences are with smaller ornamental trees, they physiology of large mature shade trees has many factors beyond this that may effect their pruning responses.
Tracy says
I purchased a young ruby tears weeping crabapple this spring. I had my heart set on that tree and purchased their last one. There was several dead branches that I pruned back. It also is missing branches on one side of the tree. I think it was damaged when it was shipped to nursery. Will those branches grow back or is the tree always going to look lopsided?
Jim says
It will look lopsided for the foreseeable future. It may eventually fill in, but it will take many years.
Kris says
I thought pruning in summer was dangerous for crabapple trees? It’s safe? I live in southeastern WI.
Jim says
Dormant season pruning is preferred but nope it is fine to do in the summer as well. Dangerous that it is harder to see the structure then in winter.
Peter says
I was wondering this too as I read the article. The reason I’ve seen cited for pruning crabapples during the growing season being dangerous is that it increases susceptibility to fireblight; is that disease not an issue in the Midwest?
Jim says
Pruning Fireblight infected branches can certainly spread the disease through tools. I always recommend disinfecting pruners between plants and even between cuts on one plant. I like to just spray my pruners down with rubbing alcohol.
Perrie Talley says
I planted a klehms impoved crabapple last year. The ones iv see around town are full , dense and we’ll shaped, while mine has long sparse branches on the bottom with no sprouting branches until the very tips. Up to 2 feet of nothing but branch. Nothing like the others I’ve seen. I love this tree and want it to be as beautiful as the others I’ve seen. Can I prune back these these branches or do something else to make them sprout foliage?? Im desperate!
Tracy says
Hi Jim,
My Tina Crab is about 10 years old. I noticed in the past couple of years that the leaf shapes were changing as well as the overall shaping of the tree, My thought was that my tree was turning into another type of tree. The cute 5 foot tree that I had planted started to grow a straight vertical trunk that sprouted other vertical branches with a mutated form of leaves. The structure of the tree has changed, the leaf shape and even the way that leaves sprouted from the branches was changing. My cute Tina was growing into a tree 10 feet and more. This year I discussed with a nursery and they told me that the grafted tree stock was staking over and that I needed to prune off the growth. I started pruning off the small outgrowth, but what still remained was the original main growth that changed the look of the tree. I did what I felt needed to be done. I cut the big branches off. I can almost recognize the original Tina now, although she does look a little barren. I feel it was the right thing to do. The question I now have is, will doing this help establish more of the Tina growth or will the root stock just keep coming back? What I find most interesting is that I find root stock branches sprouting off the tips of the Tina branches. I hope I have done the right thing. Part of the tree had died off so it would only have been a matter of time before I took the whole tree down if it continued the way it was progressing. Your thoughts?
Connie Berman says
A crabapple that was on my property when I bought it had been ‘tortured’, i.e. the previous owners had kept cutting it straight across the top. It’s an old tree, and when I bought the place I did no pruning at all, just let it grow. Now it’s more than 20 feet high, full of thin branches that shot out above the gnarled older ones. It’s a mess. Should I cut it down, or is there something I can do about it now? I can send photos if it would help.
Jim says
It can be rehabilitated, although it will be a multi year project. An experienced pruner with some skills is probably needed. If you are willing to work at it you can probably get it where you are OK with it. The nice thing about crabs are they keep growing back so you can get a lot of practice in over the years. It may be easier to chop it down too. Where are you located?
Connie Berman says
Hi, thanks for your reply and sorry for this delay. I’m in Halifax NS. Should I try to send a photo?
chris says
This was a reassuring article as we’ve had landscapers in to “prune” our beautiful, ornamental crab apple and we feel they ruined it. They cut off limbs totally from the bottom raising the whole crown by about 10 feet, when we were told they would take from the top of the crown. This gives me hope that perhaps it will grow back in?? Will it grow back in around the heaving cutting below the crown?? It has been left too tall, looking like a topiary:/
Jim says
Hmm.
It will likely sucker a lot and probably produce water sprouts from large cuts locations.
If you can select good replacement branches from the water sprouts that you can reduce to a resemble size and remove the other ones, you may be able to recover your tree to a better form. Remove all the suckers from the base of the tree as well. Good luck.
Barbara Corton says
I really enjoy your articles and this one especially. I have experienced pruning hard before and never understand why it was growing back. I have a bloodgood (I think) that is what it is called and I want to train to grow gracefully and with sparse leaves. They can get huge and thick inside.Is it possible to do that with one of those maples. I want to get good at training trees to grow laterally. Actually, every tree in my property is new and I want to make them look like they have been there a long time. I LOVE trees and just want to put more in. I always look forward you reading what you write. You seem to always answer questions I have had in my mind.
Thanks so much
Barbara
anne says
I have a sargeant Tina, 3 years old. It blooms very well. It has a trunk of about 2 ft.
I want it to be about 5 feet.
Should I cut off the lower branches so that more branches will grow on top thus giving it more height
Or should I just leave well-enough alone?
Thanks!
Annie
Jim says
If I am understanding your question right, I think you should be safe limbing it up. Crabapples are very tolerant of pruning.
Lyn at The Amateur Weeder says
That was very useful, thanks. I now know why my crabapple suckers so much. I will put your advice into practice next summer.
Michael says
This was a very helpful post. I presume these same general concepts would hold for other fruit and ornamentals as well?
Jim says
Yes, especially fruit trees. Some ornamental trees don’t react to pruning as much, but these concepts will still apply.