I’ve been searching internet to find a way to improve pawpaw survival and growth.
Oikos Tree Crops (MI) website says to top dress a cup of gypsum when planting pawpaws.
I dug further and found a horticultural science journal article that got increased survival and vigor in pawpaws grown in soil that had gypsum incorporated into the planting soil:
Interesting, I’ll look into that. My pawpaws have done well with minimal effort, but a boost is always good!
My planting directions from England’s mentioned watering pawpaw transplants with a cup of vinegar or beer per gallon of water (not sure of frequency). Cliff also says kelp meal is hugely beneficial for getting massive growth from young pawpaws (3’ in 2 years).
A treatise on pawpaws from 1905 recommends old building plaster as the best pawpaw fertilizer. If that was plaster of Paris, then that was gypsum, so there’s some potential supporting evidence.
No, but I plan to get some for seed starting in spring
Here is the quote from England’s on pawpaws…"Pawpaws should be watered with an acidic solution, (Beer or vinegar one pint to a 5-gallon bucket of water) once a month throughout the summer in addition to normal watering. Pawpaws and persimmons require a pH of 5.0 to 6.5. "
The research the link leads to is about problems with sodic soil or irrigation water from my reading, it is not intended to demonstrate the benefit of gypsum as an all-purpose amendment for paw paws. Most species would likely benefit from gypsum in these conditions.
Gypsum is often promoted as being beneficial in all clay soils but from soil text books I gather that it’s efficacy is related to sodic clay soils only. If I’d read such a text in the last few years, I might be able to explain why but it would be a simple search for anyone interested. In this case I only care about the what and not the why.
Alan- You’re right, I saw that Na reference. My record with pawpaws is so bad though I’m going to try some gypsum anyway. I do have clay, former corn/soybean field, but have no idea about Na.
I have two eight year old seedling pawpaws growing just fine so I doubt soil pH is my problem so probably won’t try the vinegar solution. It’s the young grafted, named varieties that are nearly impossible for me to get established despite all the usual steps, shade, mulch, etc.
Will try kelp meal also. I asked around and discovered my well water is very alkaline so this may explain a lot of my pawpaw troubles. Also learned the mushroom compost I put on them is higher pH than they like.
Tjasko- Am reading that gypsum in general helps nutrient uptake in many situations.
Hambone,
PawPaw are nearly impossible to grow in my area. Kansas is just not overly conducive to growing plants that want lots of water. My family grows hundreds of papaw trees in neighboring states. We have droughts, wind , clay soil, hot sunshine, cold winters , lack of shade and everything else a pawpaw hates in a place. What I did is match where they grow naturally on family property as close as possible. The first group I killed but the next group is still alive. I planted them in a protected spot right next to a pond in the shade of another tree. I walked off and left them and check them once every 6 months or so and they are fine. My mom and family can grow them no problem but in my area its not easy.
I’ve seen mention of using Black Walnuts as a ‘shelter tree’ for american persimmons (mostly from winds). Since pawpaws are juglone tolerant that may be helpful. But it sounds like your plan is working!
Pawpaw do love water and growing them beside it makes them happy. If I could give just one peace of advice I would say dig them a hole and fill it with water a few feet away and never let it get dry. My family grows their best pawpaws beside creeks in bottom ground between hills. In nature they like protected spots like that and sopping wet ground close by. I built a huge hill of dirt on the north side of them and planted cherries in the hill. I created a micro climate more void of wind, wetter, and warmer. Cherries hate wet feet so that’s why I planted them on the hill of dirt. I had to do something with the pond dirt I cleaned out anyway. Cherries and pawpaw neither like Kansas but I can grow both that way. I got a few cherries of a tree I planted in a raised hill a few years ago.
Very clever Clark. I too found them growing wild in a floodplain forest near here, and in very rich, moist, old forests. Old forest in Md is rarer than bald eagles- only a handful of postage stamp old growth patches left in the entire state.
Cliff England says he uses a soluble kelp powder for foliar feed and soil drench.
On the other side of the pond I get some real looks. I’m growing trifoliata oranges. My original hardy kiwi died for lack of water and I watered them twice a day on the hill. The last time I was able to grow kiwi for several years here but once I put them by the pond I will be able to grow them. Anne is my favorite hardy kiwi according to my trial plantings. They are something I will plant again. I created another half acre of additional micro climate ground that’s wet and wind blocked which is for papaw , kiwi , che etc. I already planted a hedge tree there to graft che to with a 20’ dirt mound directly in front of it. Water is less than 10’ down. The property was sold to me because it was always wet. I looked at the property and saw a homesteaders well and bought it on the spot. Elderberries grow everywhere which all adds up to water 10’ down or less.
Gypsum is often promoted as a solution to heavy clay soils around here too (which often have excess Na), but it is also quite useful for raising Ca levels in soils that don’t need to be pushed to more alkaline pH. I use it out here (in the West) primarily for its Ca since my soils tend to have a pH of 7.5 in their natural state.
Just bring this up to point out that its utility for Pawpaws may be more for adding to the Ca levels than correcting a Na problem.
What is pushing up the pH of your soil? Before I added gypsum in a sweet soil I’d want to know what was going on specifically, although, if something works, that is all you need to know.
My gardening education began in the hills bordering the Pacific in S. CA. I never added any gypsum but used a lot of organic matter in and on the sandstone based soil I had to work with and things always seemed to grow great.
I only learned about pH 35 years ago when I tried growing a certain vegetable in blueberry soil in the northeast. At the time I didn’t even understand the acidity of peat moss and used it universally as a soil amendment because it always worked well in the west.
That is a good question @alan, I don’t really know what makes western soils so alkaline. Perhaps related to the lower levels of precip and less biological activity than eastern soils. But is next to impossible to grow blueberries or other acid loving plants in native soil here (The local coop extension did a video about how to grow blueberries in straight peat moss bales which you bury in the soil with the plastic left on). My soils are primarily decomposed granite with some clay (but much less clay than down on the plains here). Relatively high in K but very low in N and P, and also a bit low in Ca as well as B, Zn and Mn. In the garden beds, I have added lots of manure/compost and organic matter over the years; to the point where that soil tests high in P and K (but still low in N and Ca). Unfortunately it is not possible for me to make the same soil changes in the orchard (too big an area), but I do try on a smaller scale around each tree. Peat moss is also a great organic matter addition here, but a relatively expensive one. In the garden beds, the pH is down to 6.5 or so, no doubt due to the increase in OM and higher levels of water that soil gets.
@blueberrythrill I have not checked my local Ag stores but I suspect they sell gypsum in bulk. They always have it in 50# bags here (it is used widely on lawns). Not sure what they charge in your area, but here it is about $11 per 50# bag. Actually a bit less than High Ca limestone.
It’s limestone which is mostly calcium carbonate with some magnesium carbonate. The limestone is sedimentary deposits from ancient oceans that once covered this area.
Excess K constricts plant uptake of Calcium, but you say your soil is low in calcium, not in available Ca. I don’t know enough about soil chemistry to understand how you could have a high pH non-sodic soil that is too low in Ca. except because of low CEC. If there is very little clay, that could explain Ca deficiency as well, but not a low reading of it in a soil test, as I “understand” it.