You may be on to something about we Southerners.
I was referring specifically to heading back the central leader. It’s based on many comments from the researchers at KSU and from commercial pawpaw orchardists, and was intended to apply only to Pawpaws.
It may have something to do with the strong apical dominance of pawpaws.
They are in fact generally shorter-lived trees as you mentioned.
But certainly I don’t think the original poster has much to worry about. I think we’ve given more than bargained for!!
I doubt the researchers at KSU have done any studies on the affects of heading cuts on paw paw trees, but if you can refer me to anything I would be very interested. I have one that headed itself and is about 20 years old and going strong.
It is a subject I’ve long been interested in as my first arboriculture teacher was a Shigo zealot and Shigo was practically religious about the danger of topping trees. He came to a NAFEX meeting once and suggested that FRUITGROWERS shouldn’t do it to their own trees!
But studying his research i found out of it was based on only two species of trees and that the danger of topping was based on conjecture and the tendency for topped trees to send out multiple leaders which tend to split off the tree, sometimes becoming extremely dangerous.
The thing is that fruit tree growers don’t allow multiple leaders to from at the point a tree is topped and if they want a new leader they steer growth to create a single one.
The same thing when cutting back scaffolds- the branch will be stronger if you maintain it as a central leader with nothing more than half its diameter branching off of it. It also helps save the energy expended on wood. I call it economizing wood- steer the tree to use the least possible wood needed to safely hold your crop without breakage.
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Fair enough - I didn’t intend to imply KSU has studied it, merely that they have commented to that effect in various presentations etc.
I’m a natural skeptic, and almost especially of college professors and their logical leaps beyond research. Jim Cummins once told be that the best and the brightest usually leave academia and join the private sector. I figure because he spent his life teaching and doing research at Cornell, he probably knows what he’s talking about.
Charming man. He was talking very generally about the agricultural sciences. Obviously, there are plenty of brilliant scientists affiliated with universities. that teach and use students as their “instruments” of research.
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It seems like there hasn’t been much study on paw paw pruning, so I guess I’ll have to be the guinea pig!
Interestingly, my trees already show fat buds where the flowers will be next year, so I can try to prune so as not to remove all the flower buds. As an FYI: this is the first year that the flower buds have shown up so early for me, so I’m not sure if that is common or not? In previous years, the flower buds emerged in the spring just before flowering (or maybe I only just noticed them in the spring?).
I plan to prune the two front-yard trees in late winter/early spring. I’ll update this post then to let y’all know how it goes, and probably again next fall with an update on productivity. Haha, I’ll even have the two back yard trees to use as a sort of control group! We’ll see how it goes.
It may be that they’ve observed a high tendency towards serious rot at pruning points. I will keep my eyes open for that, but my best paw paw tree almost died and lost its leader about 7years ago, I assumed it was a cambium frost injury at the time. It ended up rebounding big time. I was just eating one of its fruit a few minutes ago- it is supposed to be Sunflower and given its good quality and lack of kickback bitterness I assume it is. I’ve also been pruning them to a more open shape for years- come to think of it I can check the old cuts right now.
An earlier ripening one I have was supposed to be Overlease, but it isn’t nearly as good and has that slightly nauseating bitter after-taste.
If this is something of real concern and you don’t want to be guinea pig, I would send an email to Sheri at KYSU and ask what they do there and at the RVTs. She’s probably the most accessible person with regards to cumulative pawpaw knowledge or if she doesn’t know she can ask Kirk or Ron. Either that or give Cliff a call.
Don’t worry, I just checked several year old pruning wounds (that is, cut years ago) of branches I removed, and although they didn’t completely close as they might for most species (leaving a hole in the center of the cut) there is absolutely no sign that the wood around the old wounds isn’t completely sound so I’m just about certain rot isn’t spreading which means the tree is under no threat.
I also noticed that not just one but both trees were snapped off at the top. the one I’ve done the most pruning on looks like it also happened years ago (I’d forgotten) and there was plenty of healthy callous where it had been snapped- I assume during a storm.
I’m the guinea pig and if these things haven’t shown any consequences after all this time, I doubt they will.
You don’t need to be a phd in horticulture to be a good student of trees.
Would you feel comfortable messaging me the contact info of the people you mentioned? I am not familiar with them, but I’m happy to reach out and ask them!
Sure PM me. Neal would be another to ask, but he probably wont respond as fast as Cliff or Sheri.
It’d be quite enlightening if you’d apply the comment you make about college professors and skepticism…to the leaps they come up with about the ‘emergency’ of the climate.
I’m skeptical about most things…especially if I see somebody having a vested interest in the outcome of the ‘research’.
Back to pawpaws, they are somewhat short lived…but roots send up colonies…but this is of no help if rootstock isn’t same as variety of the top of the tree. But colonizing prolongs the pawpaw patch, even as the old tree dies after 30 or so years.
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I believe Michael Judd’s book on Pawpaw’s has a section in it dealing specifically with this. I don’t have the book on me or I’d double check. Maybe @disc4tw can verify.
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It is my understanding that grafted pawpaws tend to have a short life (generally) but as @BlueBerry said, the roots once established will send up new suckers pretty much in perpetuity as the trees die above ground. This is why it is important to learn how to graft if you want to keep your cultivars. As those suckers come up, just put another scion on top to keep your cultivar genetics going. You could always just buy a new one too, but what’s the fun in that?
I also wanted to mention - @RNeal found the parents of his superior cultivars located in the woods of the Blandy Experimental Farm. These trees may have been seedlings but may have been grafted cultivars, I’m not sure. Maybe he can clarify? Regardless, those trees were most definitely greater than 30 years of age by the time he located them, so either way the 30 year time stamp is a general life expectancy. I’m sure there are some which live far longer.
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Should have clarified. I was referring to the pruning and heading of pawpaw trees. I remember a section in that book dealing with this. I recall you referencing that book in the past…if you have it on hand do you mind taking a glance?
I have it lent currently but I have Edible Landscaping with a permaculture twist, not the For the Love of Pawpaws book. I do remember seeing someone, I believe it was Neal, posting on Facebook about a tree that was continually pruned to a shrub size. It was still very productive from what I remember. I know that on Edible Landscaping’s website the descriptions talk about which Peterson cultivars respond well to pruning. This information may have been taken directly from the Peterson Pawpaws website.
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I have never heard of any tree being terribly damaged by the act of informed pruning. In landscapes all kinds of butchery occurs of every species of tree or bush commonly grown. I am wondering where the particular concern about pruning paw paws even comes from.
Has anyone here ever killed a paw paw by over pruning it? Where paw paws grow, very early snows when trees are still in leaf aren’t all that rare. I doubt that kind of potential pruning butchery is a death sentence for any natives in our climate. My paw paw trees show the ability to heal wounds about as much as any other species I manage.
An update on paw paw pruning advice!
I used the contact form on the peterson’s paw paws website to ask about pruning, and here is Neal’s reply:
Pardon my brevity. I have too much to do.
Pawpaws can be pruned.
Open vase is wrong – works for peaches but not pawpaws.
Central leader is natural for pawpaws but it won’t keep them short.
Here I insert two pictures. The 1st one of me on a bench. The two trees are pruned annually for 9 years.
The 2nd shows the method I like to use.
Neal
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And one further update!
I had emailed Cliff England about paw paw pruning, and this was his reply:
Here is my take on pawpaw trees and we have about an acre of them.
Pawpaws trees were not meant to be shaped and cut on a lot. Sure it’s okay to top the leader on the pawpaw trees and to take cuttings up to about ½ inch size wood.
Beyond that you are inviting wood rot and insects that will bore the wood out and birds that will chip away at the dead wooden tissue in search of insects.
If cuts are made that are larger than ½ inches, use a sealer such as the one in the picture that is attached or Lac Balsam, you can find both on the web.
Thank you and good Growing
Cliff England
He had attached a picture of Dr. Stahler Wund-Balsalm to the email.
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Glad you were able to get a reply! There ya go. Cliff and Neal. Two pretty good sources imo.
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And one final update, from Sheri at KSU:
Hi Dana,
Yes, pawpaws can be pruned to keep them smaller height and width-wise. You don’t want to prune too many of the tips of branches off though, since pawpaws produce fruit on one year old wood. You can see the flower buds formed for next year already (round buds in the leaf axils), so just be sure to leave enough to produce a good crop. Pruning should be done in late winter or early spring, after the coldest temperatures are over but before they break bud. Pawpaws can be pruned to a central leader like an apple, or they can be left mostly unpruned, it depends on the space you have and your preferences for how they look, there are pros and cons to each but not dramatically different (central leader pruned trees take a little longer to come into production and produce a little less the first couple of years since you are removing some of the fruiting wood, but they are much easier to harvest from and mow/weedeat under). We did not see sunburn on any of the fruit of central leader pruned trees. Southwest injury or sunscald can be a problem on exposed pawpaw trunks in full sun, so that would probably be less in trees with lots of lower limbs to shade them, but trunks can also be whitewashed with diluted latex paint to prevent southwest injury. We have not observed a shorter lifespan of trees that are pruned vs unpruned.
If you have any other questions, just let me know!
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