Can I expect good results growing pecans in heavy clay soil where there’s temporary floods in september/october during heavy rain periods? Topsoil is quite rich in humus, then it’s red clay that holds tons of moisture during the fall. I’m not sure if pecans would thrive in such conditions or would they have issues with it. In the summer moisture levels are normal and there’s no standing water.
So I have three choices how to plant pecans in such conditions:
Red clay is not a major problem. I have pecans here at my house planted on top of red clay. Gray clay generally is impermeable to water and air so is not suitable. Pecan is relatively tolerant of short term flooding but would be better if they’re planted in a mound of topsoil at least a foot higher than the surrounding area.
Just adding to the thoughts, red clay is from air penetration of a clay soil with iron content. The iron can benefit pecans quite a bit. However, clay soils often don’t have enough zinc or nickel so do a soil test and find out what is recommended for supplements.
And there’s another place where there’s too little moisture (upland). From what I’ve read, I would expect pecans to do worse there (without irrigation). I’ve heard that shagbark hickories prefer upland. But… what if it’s grafted on a pecan? The roots would still be pecan’s, that are not the best for dry soils, does it make a difference?
Would Shagbark Hickories or Persian Walnuts or other nuts grow there better?
You ask a great question wondering about rootstock such as pecan growing in an upland or otherwise unsuitable area for pecan trees, even though the roots are topworked to a species such as shagbark which is tolerant of some upland growing. I don’t have the answers to this, but have wondered the same things. I think there can be a lot of blind spots and unstudied aspects of nut culturing that need more examination. One of them is the assumption the pecan rootstock is always the most ideal rootstock for hickory. That might only be the case in bottomland/valley/fertile habitats, and further, some cultuvars might do better NOT on pecan. People observe pecans vigor and jump to the conclusion that therefore that means it makes the best rootstock, regardless of nutritional and genetic compatibility issues.
I think a good test study would be the old Benton & Smith nursery in Wassaic NY. The context for these trees (at least most of the remaining ones) is steep, rocky, acidic hills. As far as I know, most all of those hickory selections were grafted onto the wild shagbarks as rootstock, not planted out on pecan or even shellbark rootstock. Is this because they found that the bottomland rootstocks didn’t perform/suffered, or was it simply convenience? I don’t know for sure, but do know that now 75+ years later some of the trees are still alive and producing, so that counts for something.
I wonder about grafting pecans onto seedlings of the bitternut hickory, because they grow super prolifically in some areas, whereas the pecan have the nuts not filling half the shells and the bitternuts are filled. I’ve read the not filled shells are from deficiencies in nutrients caused by either lack thereof, or high ph locking it into the soil. The areas I’m wanting have pecans and different types of hickories grow have never had either planted there before, so I’m not sure what could be gotten away with. There is loads of flint there in that area that came from the flinty limestone shelf that runs out and the limestone dissolved to some degree from the flint, so the soil may have some acidity?
Would grafting pecan onto the bitternut hickory work? Would it make for better nutrient uptake? Several black walnut trees are already growing in the are and we just clearing off the osage orange timber.
Bitternut grows slower than pecan so the pecan graft would over-grow the rootstock. It is better to get an adapted pecan rootstock IMO. Possibilities include Major and Giles. Lean heavily on Bill Reid’s info for pecan varieties. He documented varieties that produce well in your area.
Lucas, Oswego, Warren 346, Seneca, and Earlton are possibilities to graft and produce nuts. Hark and Kanza may work.
Can’t seem to find a lot of on what he says, reading where he was testing pecans was in SE KS in blueberry country?
What would be the best pecan rootstock for higher PH soil?
That is a tough question given you need both northern adaptation and high ph tolerance. I would suggest Giles as a possibility. There was some work done on rootstocks several years ago and best I recall Dodd was given good marks for conditions similar to yours. The only place I know for sure still has Dodd is ARS-Grin. IIRC, it was tested extensively in Oklahoma over the last 50 or 60 years.
Does the specific scion reduce the need for certain nutrients? Or is it just the ability of the rootstock to absorb the nutrients better than other varieties? What source of rootstock would advise? The pecans I already have grow great here, just they don’t fill the nuts out, which is greatly concerning (I do see a little scab on the husks, whould that be the cause?)
The warren 346 is the only one rated for zone 1 that has resistance to scab on that list.
I’ve also wondered about grafting some of the best sounding cultivars and then plant a bunch of the nuts of the crosses between them and try breeding something for here, but then I’d be waiting ten years to find half empty nuts?
The five varieties I listed above are good choices for your climate. You won’t have scab problems as much as pecan growers further south. You will have issues with failure to fill nuts due to the short growing season. If you are really interested, consider grafting Campbell NC4 and Meat (OC-6).
Yes, you can plant some pecans and see what comes from them even though it will take 15 to 20 years to get some production. If you get the varieties listed above, your chances of productive and adapted pecan seedlings would be significantly improved.
We have pecans planted in limestone-based clay that are doing fine. They are not in an area that gets standing water, but not in a place I would call ‘well drained’ either.
They were planted in 2008, and we are just beginning to see a few nuts (they are also not in full sun, as I planted them largely as landscape trees, with nuts just a bonus, so conditions are likely slowing growth)
The variety I planted was a seed-grown strain from oikos, back when they were a thing, which he claimed had been selected for northern hardiness (we are in zone 6)
Don’t know if any of that’s helpful to you, and I admit to not being much of a nut expert, but the trees are healthy and don’t seem to be having any problems with the clay. (or with the alkalinity, for that matter)
