Mutant limb ravaging our new baby peach tree

[omg]

Hi! I’m a first-time peach tree grower seeking your advice. I have what appears to be a mutant limb growing rampantly, and it’s spoiling my aim to nurture an open vase shape for our new baby peach tree. (A Prunus persica ‘Saturn’—Saturn Peach on Standard (Lovell) root, to be exact.)

I have a very vigorously growing limb that is extremely vertical (taller than the central leader), and it has an overly narrow crotch angle. Additionally, the problem limb is very thick – almost as thick as the main trunk. I tried spreading the limb to achieve a 45-degree angle, but I got to it too late, as it’s already mostly lignified. Additionally, I cannot gain good leverage when using a spreader against the much thinner central leader since said mutant limb is so thicc. Since it’s the strongest limb, it just overpowers everything I try to prop it up against and bends them. I also tried tying it down, but it’s so strong that it pulls the entire tree off to the side.

This is the tree’s first year. It came as a 3-foot-tall whip and was planted in early April 2024 here in NY State (Zone 6B). It’s currently September 5, and temperatures are starting to average high 60s to mid 70s, so Fall is basically here.

What should I do here? I have so many questions!

1. Should I continue to try to train the limb to a 45-degree angle to eventually make it a primary scaffold branch, or is it too late?
2. Do I need to make a heading cut to slow down the growth?
3. Or is this all futile because it’s not even a good scaffold limb, considering how thick it is relative to the trunk of the tree?
4. Do I just prune this whole mutant branch entirely?
5. Lastly, is this even the right time to prune so drastically, or is it too late in the season? I’ve read conficting advice in various books and online sources. Some say to prune early next spring before heavy growth, some say prune in winter/dormancy, some say prune before the height of Fall and Winter.

Thank you so much for the advice and rescue!!

omg

[omg]

Here is a close up

[ukie]

Since you are training to open center, you don’t need central leader.
I see that your tree has 3 nice branches going in different directions with good crotch angles, and that’s all you need for open center form. So I would cut and eliminate your mutant and leader branches entirely.
Not an expert, but I would cut now and don’t wait till late spring.

[scottfsmith]

I would just remove the leader, the mutant one is already coming out at an angle to make a vase. If you removed both it would set the tree back quite a bit.

BTW I think you are overthinking peach training, I never have needed to spread peaches as they just spread themselves over the years. They are the easiest trees to train. All I do is remove branches that are too close together.

[Melon]

I personally love the mutant growing ones. I would put those over all the other ones.

Agree with what Scott has said. I wouldn’t prune that one but again, i like fast growing trees and would prioritize the ones that act a little weird as long as it isn’t due to disease or anything alike

[omg]

Confidence inspiring advice!

I read comments from @Olpea recommending scaffolds being only about 1/2 to 1/3 the diameter of the trunk. Is that valid here? The mutant limb is about 2/3-3/4 the diameter of the trunk. And really wants to be a leader!

[omg]

When is considered the right time of the year to prune where I am in the Northeast? And what/when is considered dormancy?

[evilpaul]

Dormancy is some time after all the leaves drop off and before it flowers/starts growing new leaves in the Spring.

Here’s what I’d do.

I’d cut the mutant back to an outward facing less steep side branch now and remove the leader during dormancy.

edit: And I like to leave the plastic nursery tags on too, but move it to one of the small side branches. It’s going to be girdling the tree before you know it.

[Exmil]

I agree with this advice

[PomGranny]

Could it just be a hardened sucker that arrived when the whip was cut off at the height that the person (with the clippers) wanted the tree to start branching off?

Whatever it is - I’d cut off the one that doesn’t Go With the Program of an open center.
And, for what it’s worth (from a pretty newbie fruit grower) . . . I have found that Less is More when it comes to picking the number of main scaffold branches. I have used the North-East-South-West method of choosing the branches that stay. And in most case I end up wishing I’d only left 3. Or actually go ahead and amputate one of the 4 to open things up! Fruit trees tend to get so crowded - so fast - whether Central Leader or Open Center - or a combo. You won’t miss a branch - even though it seems like a mortal sin when new at all of this.

[omg]

Thanks! So I can learn the biology, why is it ok to do a branching cut of the mutant now but should leave the smaller leader cut until dormancy? I’m still learning about best time to do different types of pruning.

Also, interesting point about 3 vs 4 scaffolds. 3 seems more focused for nutrients vs 4. What are everyone’s feelings on 3v4?

[evilpaul]

Cutting the mutant now will (probably/hopefully) reduce its dominance and get the other branches to grow more into the equal sized open center you’re going for. I would leave the central leader for now because it’s late in the year, and it’s collecting energy for the tree for next year. The trade-off of cutting it now versus cutting it when dormant is a marginally smaller pruning wound to heal versus less energy stored for the tree to grow with next year. Waiting isn’t a significant detriment. Acting now isn’t a significant benefit.

[Olpea]

@omg

Lastly, is this even the right time to prune so drastically, or is it too late in the season? I’ve read conficting advice in various books and online sources. Some say to prune early next spring before heavy growth, some say prune in winter/dormancy, some say prune before the height of Fall and Winter.

There is a lot of different advice out there on timing of peach pruning.

I think part of it results from different climates. It’s probably fine to prune peaches in dormancy in milder climates.

In my climate here in the more northern part of KS and MO, you’d want to avoid pruning in winter. In fact, I wouldn’t prune peaches here, even this late in the growing season, unless it was a very very light pruning. There is plenty of research which indicates late season pruning somewhat inhibits peach trees from fully hardending off for winter.

In terms of the specific shoots to prune from your pics:

If it were one of my trees here in KS/MO (I have peach trees in both KS and MO, since I live on the border of the two states) I’d wait till the beginning of the next growing season, and head back the smaller vertical leader to about 8" above where the mutant limb attaches to it. I would also cut the mutant limb completely off.

The reason for leaving an 8" stub of the vertical leader is that it would give more choices for more scaffolds, if need be.

I can’t tell what I would leave of 1, 2, 3 scaffolds. Number 1 looks really good. I like to put some vertical distance between scaffolds connecting on the trunk. Preferable three or four fingers vertical distance, but sometimes it doesn’t work out.

All that said, Scott wrote it well. Peaches don’t need to be spread, unless one is trying to get them into production in fastest possible time. And, it is easy to overthink it.

But, imo, I’ve found them harder to train than malus fruits, and many other stone fruits. This for the simple reason peaches don’t as readily throw adventitious shoots, like most other fruit trees.

Still, I haven’t so far read a single suggestion on pruning your peach tree, which I would say is wrong.

Pruning peaches is a little bit like drawing in a color book. One can’t say one coloring is wrong and another right. There are a few basic rules to keep one coloring inside the lines, but beyond that there’s a lot of liberty in selecting shoots to make scaffolds.

[JohannsGarden]

The original leader is crappy and the tree is replacing it. Remove the original leader and be grateful. It’s not a mutant. It’s doing the right thing.

[Brisco]

Yeah, they labeled the old mutant “leader” and the new leader “mutant.” Hilarity ensued