Working around native fruit trees

[Ludi]

There's an area of the "homestead" part of our land where I would like to establish a food forest beneath the canopy of existing Oaks and Elms. We expect the Oaks to die in the next decade from Oak Wilt, but the Elms seem to be doing fine. Since we fenced this area off from sheep and deer, a lot of little native fruit trees are coming up, Gum Bumelia Bumelia languinosa, as well as other interesting and somewhat rare understory trees such as Eve's Necklace (not edible as far as I know). This is an area of shallow soil over rock, our climate is hot and dry. Any special suggestions about how to establish more edible plants among these existing trees? Do you think making heaps of brush and other organic material between the trees and letting those rot for a few years before trying to plant would be a thing to try? Or should I try sowing green manure and slashing? I'm concerned with the shallowness of the soil and lack of moisture.

If photos of the area would be helpful I can post some tomorrow.

[matto]

Nature helps those plants waiting to become the next canopy layer in a forest by creating a disturbance. If you think you might lose the oaks, why not harvest now for shitake logs and you will have created an opening to watch the next stage of succesion or by creating your own anologue forest with known hardy but productive trees for your area.

[Finchj]

I'd sow a green manure and see what happens. If you can make good seed balls, toss them out, and perhaps cover with some of that brush you have? Even if they don't sprout right away, you might be able to get some really useful cover crop seeds into the bank- in case you get lucky with some great growing weather.

[Ludi]

known hardy but productive trees for your area.

One of my problems is I do not know of such trees.

[adiantum]

Sounds like some observation is in order so as to better inform your action. What kinds of useful trees are growing in your area, both wild and cultivated? What useful plants seem to be able to persist with neglect and volunteer on neglected sites? From my years in Georgia, I would look at plums, peaches, crabapples, figs, mulberry, che (Cudrania), pecans, persimmons.
Shallow soil over bedrock is going to be a problem no matter what is growing....I dare say even the native oaks and elms are stunted compared to the way they look on deeper soil. On a small scale, you can import or concentrate organic matter and topsoil in mounds or edged areas and deepen the soil. Irrigation might be essential for productivity. Where there's a will there's a way. I have heard of orchards in Florida laid out in shallow sand over coral rock by drilling holes in the rock and blasting cracks into it with dynamite!!

[Ludi]

Thanks for those suggestions. I don't know how to find out what trees might do well here with neglect, as I have killed many kinds of trees with neglect, including figs, plums, pecans, mulberries, persimmons, pears, jujube, apples, almonds, nectarine, peaches, crabapple....Probably more I'm not remembering....My entire orchard was killed by drought. That's why I'm trying to figure out how to replant in a place where the trees might not be exposed to such extreme conditions in our current drought, which is expected to persist.

[adiantum]

In the majority of the world's climates, and certainly wherever I've lived, one needs to be able to irrigate new plants for the first season or two, especially, to get them established. I've found the hard way that it's beneficial to create patches of disturbance/intervention in which I grow annual gardens and place permanent plants and new trees among them. I had very bad luck trying to tuck new trees, etc. scattered through a basically wild ecosystem. I found that roots of the surrounding wild trees invaded the improved spots provided for the new plants....to the extent that I found that trees I was watering dried out faster than others nearby left without!! The patch system disturbs enough area to hinder this process. I improve the soil and provide water, etc. and bring off my crop from the vegetables, etc. growing there until the trees get big enough to cast significant shade. The trees benefit from the water and attention given to the annuals. This is also a good practice where there are intractable weeds (nutsedge and bermudagrass in GA) that can be subdued with regular cardboard/paper sheetmulch...enough to grow some garden based on transplants; but never completely eradicated. Dealing with these weeds taught me the benefit of moving the annual garden around the landscape every few years, and with each move, trees and perennials would be left behind that could deal with the resurgent weeds. Basically a variant on shifting cultivation or milpa system.
Of course there is the possibility that your site might be so marginal that you will need to be able to provide irrigation to everything, indefinitely. The keys to such a design are to not overextend your plantings beyond the water sources available, and to seek multiple sources for water.

[Ludi]

How large do your patches tend to be?

[adiantum]

I'd say enough to put at least three fruit trees in. Single tree spots work, too, but it needs to be a disturbed, sheetmulched spot at least 10-12 feet across, and you need to commit to grow other things in it and tend it like garden. I've also worked with larger orchards of 20-50 trees, first in more or less solid garden, then strips of garden in between the trees, and finally no annuals except covercrops in the winter once the trees cast a lot of shade. It's a way of working with, rather than against, succession.

[Ludi]

Thank you, that's very helpful. I'm hoping to remove some less useful trees to open up spots in this little wooded area where I might be able to get some fruit trees and shrubs growing, and maybe some perennial food plants as well. This gives me an idea of the size of area I should try to open up.