That’s one beautiful pawpaw tree. Wow.
In general try to group all your pawpaws close together. I did not know about this when I planted mine about 20 feet apart which is too far.
Pawpaw wounds heal very slowly so grafting into such a mature tree probably isn’t a good idea- the wounds would be so big. Plus beheading them would ruin aesthetics. I would plant two or three new ones in between the existing mature ones. I’d plant Susquehanna, KSU Atwood, KSU Chappelle, maybe Greenriver Belle.
It’s simple. Here’s what you do. Don’t bark graft. Top work it. Treat it like how they rework apple trees.
I kept my central leader shape of my mature pawpaw by grafting to apical side limbs/branches. You don’t notice the difference until you get close enough. The same amount you remove for the graft is the size replaced from the new scion. Best part is that you get fruit so much faster. Grafted last year. Got fruit on those new grafts this year. The only down side of this approach is that you need LOTS of scionwood. Make sure you have the proper friends to supply it. I went through multiple 1 gallon bags full of scionwood.
Interesting. My pawpaw grafts on small or horizontal wood languish. My only pawpaw grafts that really thrive are vertical on a fat section of the leader with little to no nearby competing limbs. In other words, beheading. My pawpaws love to grow around my grafts on small or horizontal wood rather than through them, given half a chance. I had same experience with persimmon.
Over time and experimenting I learned to harness their strong apical dominance when I graft.
@JustPeachy So if your detailed topworking is working you’re doing something right! Did you topwork 100% of the tree? If so I can see how you forced the tree to cooperate.
I may give it a shot next spring with a few graft and see what happens. Worth a shot
You don’t do it all at once. You do it bit by bit throughout the canopy. You still need nurse limbs. I leave these undisturbed till the next year when they are replaced/grafted at which point the previous year’s healed/grafted over limbs then serve as nurse limbs. Also, the size of the limbs and apical tips on my pawpaw are still pencil thick up to 1/2 inch diameter grafts.
This is a 1/2 inch secondary limb grafted last year that fruited this year. First fruit harvested about a week ago.
Well done, very interesting. I suspect my sandy/droughty soil doesn’t support lush growth like that even with deep wood chips and spring NPK.
That might be even better for a pedestrian orchard. My 15 year old tree is 16+ feet tall central leader. I need a ladder to work the top.
This is a similarly age 15 year old tree that Neal Peterson grafted for his friend and was planted about an hour south of my location. It’s grown in hard deadpan yellow clay soil (mine is rich loam). This pawpaw pictured above is a squat bush less than 6 feet tall.
Pawpaw bushes exist. You just need the soil for it.>_<
That’s a beautiful tree that the OP has. I wonder if the blooms/fruit simply got zapped by a freeze this year. I’d be real hesitant to do any major top working on that tree unless I knew for sure that it produced inferior fruit. But I think grafting a few branches in there would be a great idea and lots of fun, even if it turns out to be unnecessary for pollination. Many great suggestions for that above.
I would have thought 30 ft between two big trees would be ok for pollination but that’s just a guess. If they are not clones, but distance is a problem for pollination, it’s pretty easy to hand pollinate to get a crop.
I should point out that even with a varietal branch grafted into the middle of the canopy, that still won’t necessarily ensure proper pollination.
I posted this the other thread.
On my fraken-pawpaw, I have replaced enough of the secondary limbs in the upper and middle canopy that without hand pollination, I still get a decent bit of fruit. (We’re talking about something like 50+ something grafts at this point.) I would still recommend hand pollination if you can do it. It’s really very easy if you have a few grafts on a each tree though. Paintbrush in one hand, dab pollen from the graft and move 1 foot over to non grafted flower, or vice versa. You don’t have to move from tree to tree. Or collect pollen and move between trees. Each tree is self contained in a sense.
Recommendations from various sources are to have your trees about 8 feet apart. The natural pollinators (beetles and flies) are not necessarily good at their jobs, which is a major reason wild pawpaws reproduce clonally, by sending up shoots from their roots. That clonal reproduction is one reason why you get patches of wild pawpaws that never seem to produce much fruit. So get some scion wood (check with Kentucky State University and England’s Nursery also in KY) and do some grafting, or get a few trees of other varieties and plant them nearby.
How far away from the existing trees? How close together?
Because the flowers are pollinated by beetles that have somewhat limited mobility and by flies (not sure what species) that are attracted to the light carrion scent of the flowers, having trees 30’ apart with mowed lawns and asphalt between and around them does not provide much habitat for the natural pollinators. They aren’t like honeybees that will fly 5 miles to a patch of flowers. Some folks recommend putting fresh manure, roadkill, meat scraps, chicken remains, etc., near the trees. Household members or the neighbors might object.
I would suggest having trees ~ about 12ft. Apart to give them room to develop to a full mature size.
And up to / within 30ft. Apart for pollination.
More or less
Other spacings will work.
I just listened to a podcast where @RNeal discussed his orchard spacing for selecting cultivars at 3 foot spacing. However, he did qualify that spacing by saying it was suitable for getting the fruit to production size, not to continue harvesting from mature trees. When you have around a thousand trees and only an acre or two to work with, you go with the spacing you are able to!
I think this makes total sense though. The objective is breeding in this scenario; you’re trying to maximize the number of seedlings in a given area, observe the largest possible number of potential candidates. Improving fruit size can be tweak with soil, thinning, fertilizer, etc… You can’t improve the genetics of an existing cultivar. It’s almost like nursery planting 1-2 feet distance. The are expected to be dug up for sale. They aren’t permanent plantings. If you’re going for production, you’re obviously not in the same boat.
I absolutely agree. Different strategies for different purposes. I feel like the ideal planting distance varies greatly based on how a tree is used, especially for training pawpaws. Unlike other fruits like apples, no dwarf rootstock exists so it comes down to how the tree is pruned more so than apples etc.
I think a dwarf rootstock could exist. They have to first figure out a way to reliably clonally propagate pawpaws. Until that happens, any rootstock program is basically a no go.
This kind of mirrors the peach industry with one major exception (besides the fact that stone fruits get plenty of research funding). UCDavis only recently released dwarfing 100% prunus persica rootstock, but tissue culturing peaches was never as hard as it has been for pawpaws.
Similarly to a discussion recently about cloning apples, it’s entirely possible a pawpaw is out there that can be propagated easily via root suckers like M111 which might be a dwarfing rootstock. Hard to say, and I imagine we are a long way away from that. The one way I can think of to reliably do this with current availability would be grafting onto a smaller Florida based Asimina sp. but you risk cold hardiness.
Maybe. You’d still have to find the right one of the Florida/Texas/souther Asimina sp. … and even if you did, since the species aren’t self-pollinating like you can with P. persica, you still might end up losing that trait in the seedlings.
They need to figure out how to either tissue culture or stool bed pawpaws for this to be a viable option. Since stool bed is a no go (unless I’m missing something recently), tissue culturing still seems to be the most viable to address this, but again, no one has figured out how to do this with high degree of success. I remember reading a research paper that some Italy university was experimenting with tissue culturing A. triloba , but the process had to be rigidly followed and had a very large margin of error/failure. Still they had the best success ever recorded thus far according to KSU. (I don’t remember the title of that paper, but KSU folks could point you there if you are looking for it.) I do remember that it was not a commercially viable process, simply more labor, resource (chemicals), and time intensive than just the regular tissue culture process.
If it was easy, someone would have surely figured it out by now… 
