Hard Pruning During the Growth Season

[0soyoung]

I have a tree that needs to be cut back dramatically. It is now leafing out. I have three horticultural questions for BNuts willing to help me out.

FIRST QUESTION: Is it better to do the hard pruning now or to wait until after the foliage has hardened?

SECOND QUESTION: Should I prune a few branches in one session, then more in another a few weeks later, and (if there is more) the rest after another equal waiting period, OR should I do all the pruning in one session?

THIRD QUESTION: Should I ‘chase back the foliage’ meaning my pruning should always leave a few leaves on each branch/shoot/twig of the finished form OR can I prune back to visible buds OR just lop it back to exactly what I want and not worry about foliage or buds because it will make new buds and then leaves anyway.

An alternative single question is what should one do to kill a branch or specific branches simply by pruning? With this answer, of course, one would not do that; but I don't know that answer either.

 

[rockm]

It would help greatly knowing what species your asking about. This can vary. Hard pruning a princess persimmon as it sets foliage can kill branches, while hard pruning a hornbeam after leaves harden off can force massive backbudding...

 

[Poink88]

It would help greatly knowing what species your asking about. This can vary. Hard pruning a princess persimmon as it sets foliage can kill branches, while hard pruning a hornbeam after leaves harden off can force massive backbudding...

I agree 100% with this.

 

[PaulH]

Species absolutely makes a difference. But in general I would wait until new growth hardens off before any major pruning.
There are a lot of variables though. If you're completely removing branches and leaving a lot of healthy ones I would do it at any time, but it will heal faster during the growing season. If you're shortening branches and want back budding I would do it in late May or June here.

 

[0soyoung]

It would help greatly knowing what species your asking about. This can vary. Hard pruning a princess persimmon as it sets foliage can kill branches, while hard pruning a hornbeam after leaves harden off can force massive backbudding...

Let us say, Japanese maples. But wouldn't princess persimmon indicate that it is a bad idea to prune any deciduous tree during leaf emergence?

 

[0soyoung]

Species absolutely makes a difference. But in general I would wait until new growth hardens off before any major pruning.
There are a lot of variables though. If you're completely removing branches and leaving a lot of healthy ones I would do it at any time, but it will heal faster during the growing season. If you're shortening branches and want back budding I would do it in late May or June here.

Thanks. Does it matter if I shorten all the branches at once as opposed to doing it in phases? Or, which way would you do the pruning?

 

[tmmason10]

I'm in a similar situation with Japanese maples, so awaiting some more responses from seasoned veterans. I would think that prune back after they have hardened, would be ok as it is the same time defoliation can be performed?

 

[Don Blackmond]

Let us say, Japanese maples. But wouldn't princess persimmon indicate that it is a bad idea to prune any deciduous tree during leaf emergence?

Now is a perfectly good time to prune japanese maples.
Do it all at once.
Cut back to where you want, keeping in mind that there is usually a reason for choosing that spot.

The health of your tree is a factor to consider. Proceed as long as its healthy.

 

[rockm]

"Let us say, Japanese maples. But wouldn't princess persimmon indicate that it is a bad idea to prune any deciduous tree during leaf emergence?"

Not really. Depends on species. Ideally, hard pruning should be done BEFORE leaf emergence. It can also be done to a certain extent after leaves have hardened off. The primary reasons for hard pruning are initial design and forcing back budding. The design aspect is pretty self-explanatory. The second reason is to induce ramification. Soft wood (wood that hasn't lignified or hardened off) doesn't, for the most part, carry the hormones necessary to induce backbudding. Wood that has hardened off--after leaf formation--carries hormones that are capable of activating resting buds behind the cut. So if you clip a woody end off a branch, you're probably going to get significant backbudding from resting buds on the remaining limb or part of the tree in the immeidate vicinity of the cut. That's because the hormones that once travel to the end on an established path through woody tissue have no where to go and activate the resting buds.

This is my understanding of things, may be completely inaccurate....

 

[Poink88]

Soft wood (wood that hasn't lignified or hardened off) doesn't, for the most part, carry the hormones necessary to induce backbudding.

I am a pincher and I disagree. I have lots of plants that are back budding because I pinch regularly.

This is my understanding of things, may be completely inaccurate....

I agree.

Not trying to pick a fight just can't resist. LOL

 

[0soyoung]

Soft wood (wood that hasn't lignified or hardened off) doesn't, for the most part, carry the hormones necessary to induce backbudding. Wood that has hardened off--after leaf formation--carries hormones that are capable of activating resting buds behind the cut.

This is my understanding of things, may be completely inaccurate....

I think 'hardened off' refers to the foliage and not the wood: when deciduous leaves are all unfolded, fully colored, and no longer limp; when needles are pointy, dark green, and don't come off easily (super easy?). In this 'hardened' state the foliage is photosynthetically active and exports sugars and auxin. It does not when it is emerging, pale colored and limp.

 

[rockm]

"I am a pincher and I disagree. I have lots of plants that are back budding because I pinch regularly."

How's that workin' for ya' on that korean hornbeam?

 

[Poink88]

How's that workin' for ya' on that korean hornbeam?

Working well...believe it or not.

Are they not supposed to back bud when pinched? (serious question)

 

[rockm]

Well, there's back budding and BACKBUDDING on KH. I used to pinch soft growth with mediocre results. Switched to clipping back new twigs after they hardened off and had much more success.

 

[Poink88]

Well, there's back budding and BACKBUDDING on KH. I used to pinch soft growth with mediocre results. Switched to clipping back new twigs after they hardened off and had much more success.

Thanks. So far all the ones I pinched a week ago are producing several buds so it is working for me in building some ramification and adding movement.

This is my 1st KH (have 2 now) so I am experimenting and treating them same way as all my other trees. They all get pinched....until I find out which doesn't respond favorably to the treatment. So far all are okay. Could be our warmer weather.

 

[iant]

In my mind the main reason not to prune just after it's leafed out is that you're wasting the plants energy. The tree just used energy stored in the roots and 'invested' it in a new set of leaves and shoots. So if you cut that off just after formation you haven't given those leaves a chance to work and store energy and give payback to the tree on its investment. So it's basically an energy waste. If you wait until fall it's a net gain and you should still get the budding you want. Patience. Of course Don is right that with a healthy tree you can do it. I'm just not sure it gets you where you want to go in the most efficient way.
Ian

 

[tmmason10]

In my mind the main reason not to prune just after it's leafed out is that you're wasting the plants energy. The tree just used energy stored in the roots and 'invested' it in a new set of leaves and shoots. So if you cut that off just after formation you haven't given those leaves a chance to work and store energy and give payback to the tree on its investment. So it's basically an energy waste. If you wait until fall it's a net gain and you should still get the budding you want. Patience. Of course Don is right that with a healthy tree you can do it. I'm just not sure it gets you where you want to go in the most efficient way.
Ian

Great points Ian, I am in agreement with you on this.

 

[fourteener]

In my mind the main reason not to prune just after it's leafed out is that you're wasting the plants energy. The tree just used energy stored in the roots and 'invested' it in a new set of leaves and shoots. So if you cut that off just after formation you haven't given those leaves a chance to work and store energy and give payback to the tree on its investment. So it's basically an energy waste. If you wait until fall it's a net gain and you should still get the budding you want. Patience. Of course Don is right that with a healthy tree you can do it. I'm just not sure it gets you where you want to go in the most efficient way.
Ian

Doesn't waiting to pinch it off create long internodes though. I have been cutting the first growth spurt to keep a short internode, then the second bit of growth, I let it grow out. The second bit of growth has shorter internodes for the future budding.

I'm not saying any of this because I know I'm right. If there is a better way I'm all ears!!

 

[Poink88]

In my mind the main reason not to prune just after it's leafed out is that you're wasting the plants energy. The tree just used energy stored in the roots and 'invested' it in a new set of leaves and shoots. So if you cut that off just after formation you haven't given those leaves a chance to work and store energy and give payback to the tree on its investment. So it's basically an energy waste. If you wait until fall it's a net gain and you should still get the budding you want. Patience. Of course Don is right that with a healthy tree you can do it. I'm just not sure it gets you where you want to go in the most efficient way.
Ian

The way I see it...is like a deposit every time a tree creates a leaf. When I pinch...it is like making a small withdrawal. When someone waits and prunes back later...it is a major withdrawal. For me, in the end pinching is more efficient since after that, I am not touching any leaves left. Just my way of thinking and is definitely not for everyone. I am happy with my results though so I have no plans on changing it.

As Fourteneer said too...I get shorter internodes and smaller leaves. Some will say it is a sign of a weak tree (and it could be) but I do not believe it is true for all. Yo can have a healthy tree with smaller leaves and shorter internodes...it just depends on how much foliage your tree have.

Again, to each his own.

 

[iant]

I wasn't referring to pinching. I was referring to the title 'hard pruning." They both have their place and I don't think they need to compete. Sometimes the growth has already happened and you gotta chase it back or adjust the design. Obviously if you're refining and you're on top of it you're probably pinching. This post was asking about the timing of hard pruning. Pinching is a different technique and a different topic really (IMHO.)
Ian