Trees sapping moisture & nutrients from the garden

We have a garden plot that is hacked out of the woods (in Missouri) and we have given ourselves 25 feet or more around the plot for sunlight. I have used this plot for onions, garlic, some tomatoes, potatoes and squash over the years and it's done well...EXCEPT the north end of the garden. All plants in that end of the garden (maybe 6 feet of the plot) are stunted. The soil gets as hard as concrete, it won't stay moist when the rest of the plot is moist. The plot is flat and there is no run-off of water anywhere so this dryness in the north end is such a puzzle to me. There are two trees (small persimmon and another ?? maybe 25 feet tall with small slender trunks) that are left nearer the garden on the north side. My husband wants to cut down the two trees but I'm not wanting to do so. Can these two trees be sapping away all the moisture and nutrients of that end of the garden? It seems unlikely to me but I'm puzzled. Any ideas?

Most trees will  compete with plants for moisture and nutrients, usually not beyond the drip line of the tree.

The concrete though sounds like there may be other factors at work, you might check the organic/humus content of the soil--shake up a jar of water and soil and let it settle out the humus will be the top- compare the good soil with the concrete.

You could also have problems with drainage --is that up slope from the better parts of the garden? longer raised beds on contour might go a long way to improving moisture, nutrient content, as well as swales on the sides of the garden bringing in extra water.

At any rate  growing gardens on actual concrete with raised beds is possible with enough amendments so there is likely some hope for that part of the garden.

Cutting the trees might be a magic bullet that solves all the issues, but likely you will still have to build the soil structure with lots of organic matter.

Down here in VA where I live there are trees everywhere and the soil under them isn't fit for a garden, clay and rock, but the trees are quite happy. I try and leave my trees to photosynthesize until I actually have to cut them to let in the light--loss of sunlight can be a very detrimental factor to a garden.But the extra organic matter from the extra photosynthesis from letting the trees grow a little longer can be a greater benefit to building better soil.  The soil is the bank for carbon, the trees are pulling the carbon out of the air. I would never say to never cut trees, but it is something that definitely needs to be balanced with all the other factors in the situation.

Sounds like a wonderful challenge to experiment with.

If your soil dries up and gets hard as concrete, it needs organic matter.  The solution is mulch, mulch, mulch.  

Every garden needs a "pile it up and let it rot" area.  I've got several of these around my property.  I usually try to pile up old branches, corn stover, sunflower stems, any available leaves, spent tomato plants and other viney stuff that doesn't compost easily  --- any available biomass ---- make about a 4 or 5 foot high pile and then leave it alone for a couple of years.  I put my piles on the south side of my fruit trees, particularly on a south-facing hillside that tends to get baked by the sun throughout the summer.  These piles of slow-to-rot organic matter are lizard nurseries and earthworm factories.  After a couple of years when I move a pile, I'm always stunned with how beautiful the soil is beneath.  Rich and black and crumbly and full of fungal life.

And every garden needs a space where you can pile up a couple of yards of wood chips and let them slowly break down for a couple of years.  Any chance you could flag-down a wood chipper truck and get them to deliver a load of chips?  Then pile the chips high back there in that poor spot and let them slowly break down over the next couple of years.  Once they've broken down, the soil beneath will be amazing and the chips that remain can be spread throughout your garden as a wonderful mulch.

In Permaculture, it seems that no matter what the question is, the answer is more organic matter.

Thanks, Marco! Yes, I do think that this is a wonderful challenge for experimentation and I love your ideas. This area is a bit of an orphan, a ways from our home and my main garden. It is not fenced and in our area a garden without fencing is merely deer fodder. Deer don't eat the things I plant here: garlic, onion, potato and tomato. They will eat the squash vines but if I can get them going good, they only stunt them and they don't destroy them. Anyway, I just finished mulching my main garden with the wood chips from the County. I'm new to the whole concept but I'm sold!!

I'll do my best to get a pile going in this particular orphan garden and on that North side and see what happens. The roots of the two trees I mentioned shouldn't do that much stealing, I don't think, as I understand the concept of permaculture...but the puzzle of why was still there and my husband's solution was to cut down the trees. I do want to experiment and see what happens.

Thanks for the good suggestions!

The trees are most likely at least part of the problem. I'm in MO. It gets dry enough here that with tree roots sucking up moisture it could get like concrete. Most of our soils have clay. Organic matter always helps, and experimenting is great.

I'd ID the trees first. If there are any walnuts around, juglone could be part of the problem.

Do you have access to a tractor? The Ag Services Office has root plows that farmers use to trim roots around field edges.

I love trees, but you might have to decide if the garden is more important or not. What type of trees you have could be a factor to consider. Are the persimmons edible?  Most are pretty good. Some are great. The only tree I have access to now is still too bitter to eat. They are never any good. If I owned it, I'd cut it to get it out if the gene pool and make room for something else. Well, I might graft a good variety on to it.

About the deer, I would recommend not planting sweet potatoes or cantaloupes. The deer here always eat all the sweet potatoes then all the cantaloupe vines. They don't usually bother the rest much unless they are very hungry.

At my place, I figure that there is no point planting annual vegetables near a tree. My general rule of thumb is to not plant closer than the height of the tree. So if a tree is 30 feet tall, I don't plant annuals within 30 feet of the tree. I plant things like bunching onions, strawberries, mint, raspberries, and spring bulbs near trees.

This year, I ignored that rule-of-thumb, and planted squash closer than that to a tree. (The smallish trees are about 16 feet to the left of the stunted row in this photo). The row on the right is 8 feet further from the trees, but is still being negatively affected.

Wow! that picture is priceless! That's what I've experienced. Since I am fairly new to the permaculture method, I felt a bit guilty about cutting trees but thanks to your comments, I see that I must be smart about placement and balance the value of the tree to the value of the crop! And yes, in our part of Missouri, we are clay, too. I used to think it was horrible but with the addition of some good organic matter, it is a marvelous soil for gardening.

Thank you for the rule of thumb about height to distance from the tree of annuals. I needed to have that hammered home to me. In my excitement about permaculture, mulching, etc. I tend to just think it is all going to work perfectly if I just mulch and have a great variety. Ah well....still learning.

Thanks so much for all the comments!! It helps to talk things out with people who are passionate about this! ...and people with much more experience than me.

What part of the state are you in?

We are located right in the middle of the state of Missouri, just about 15 miles south of I-70, which cuts Missouri in two east to west. Interestingly, weather is quite different North of I-70 than South of I-70. They get far more snow and wind and ice north of the interstate. Lots of storms break up and go north of us. I'm in Zone 6a.

Well I would agree with a lot of te posts that your trees may not be the only problem. Permaculture is about working to your strengths, what are the positive things about having a patch of dry land? I can think of a lot as I come from waterlogged area where no amount of trees can drain the soil! If you need more land for growing I would look for an area that isn't dry and hack up the trees from that area instead. I mean if your gonna need to take down trees why take them from a bad area of soil where tey are thriving? Maybe a tree is te only thing that can go deep enough to bring up moisture. Your also never draining anything really, just converting it. So the tree is converting moisture into leaves and that's a valuable product. I think mostly trees drain below surface, except for some shallow rooted trees so if the area is super dry it either gets no rain, drains too readily, ie there might be a pocket of sandy soil that allows water in bit doesn't let it stay, or it is on top of perhaps a boulder so it's roots are taking surface moisture. If that were te case then taking them up would leave you with better moisture but you probably won't know till you dig down. Where you can go around something rather than through it go around it. And where you have a situation work to it's strengths. Honestly here it's so wet, so so wet, and I would even cry for how wet it is, but that's the reality. And you either work with what is, or against it. And often the fight is long hard and brutal and you don't win anything, and sometimes just changing your plans to fit the environment is less of a struggle and more of a creative parameter. Blue berries. They grow great in bogs. So I grow berries. And you find the thing tht works. What works on dry soil? Picnics. Buildings, smoke houses. Fire pits. So many things that are wonderful about a dry patch and if you get rid of it you'll find some need for it and be at a loss of how to recreate such a lucky coincidence! Swap ya a few yards of bog for somewhere dry to change my wellies?? Any time!!!

Yes, trees can rob moisture and nutrients from a garden, I've been experiencing it personally here in Missouri too. There are lots of factors including type, size, and density of the trees as well as soil depth and organic matter. I have a couple of spots along the edge of the garden that have some dense medium-sized trees (up to 12 inches DBH) just on the north and nortwest sides of it (and slightly uphill). The garden is beyond the driplines of them and not shaded by any of them until late afternoon. This area has been gardened for several decades and the organic matter has built up considerably, but it doesn't have too much depth to it, a rock slab that is visible in parts of the nearby woods is probably not more than a few feet below the surface there. The ends of the beds nearest the trees do fine when there has been enough rain, but when it gets droughty it seems no amount of irrigation can keep the area moist, and the ends closest to the trees wilt and are stunted while part of the same row further away are fine.

Observing the area further, I've noticed that the older trees in that patch of woods tend to be cedar, chinkapin oak that isn't all that tall, and other species characteristic of droughty, thin, nutrient-poor soils. However, the younger growth is pretty lush, characteristic of richer soils, although the area still dries out easily. The edge nearest the garden grows the densest, lushest trees. Since the garden has been there a matter of decades (it hasn't been me working it that whole time), I've realized the trees were only growing as lush and dense as they were because of taking water and nutrients from the garden. They would never have survived for so long growing so densely in that site otherwise. Trees and/or mycelia had also slowly been moving fertility up the slight hill from the garden into the nearby woods.

Just a few months ago, we finally thinned out some of the trees. We left some, but I hope that less competition will mean the remaining ones don't need to draw so heavily from the garden. Thinning will benefit the remaining trees too. In Missouri, most of the woods historically was more open in presettlement times, and many of our most common trees such as oaks and hickories tend to do better in a more open woodland setting too, particularly where the soil is thin and droughty.

Joseph Lofthouse's rule for the planting distance from a tree sounds sensible and probably practical on a dryland acreage. But here in the Ottawa Valley of eastern Ontario I have way too many trees to get my veggie garden that far away. As a consequence, I've clearly seen the network of roots from trees 20 feet away that invades a garden within a couple of years. I built a raised bed garden years ago on a city lot that offered enough sun for veggies, and it produced well for about two years. After that time, I noticed a lot of fine roots whenever I worked the beds, and the production really declined despite conscientious watering. A maple at least 15 feet away seemed to be the predominant root source, although a nearby cedar hedge was likely contributing to the competition. That taught me that simple raised beds don't help much (or for very long) with the problem, and I see the same problem in my current garden. Apart from taking down numerous trees, which is impractical and mostly undesirable, I suspect that regular root pruning of the nearby trees is the best way to keep down the competition. I don't have the space to use a root plow, as Ken Wilson suggested, so I'll have to try a more manual method -- maybe a pickax trench.

Ken W Wilson wrote:About the deer, I would recommend not planting sweet potatoes or cantaloupes. The deer here always eat all the sweet potatoes then all the cantaloupe vines. They don't usually bother the rest much unless they are very hungry.

Or get a good guardian dog - Great Pyr or Kommondor. I'm here in Midway, just outside of Columbia, MO. We have a Pyr-Kom mix and don't even see deer anymore. They do boom like cannon, though, so consider the neighbors!  I've been overrun by cantaloupe the past two years.

How do you do root plowing? How do you balance cutting the roots with keeping the tree healthy? I've pruned trees and saw great improvement in their health, but I've never heard of doing something similar with the roots.

if the two of you differ about removing the trees or not, try a compromise. Heavily prune the trees but allow them to live. The roots will stop taking so much of the nutrients and water, and a heavy prune will cause a lot of root to die, becoming food for other plants. Doing this will give you a quick answer to your question of whether the trees are the problem, and once you have observed the result for 6-12 mths you can decide whether to prune again, allow them to grow back, or even completely remove the trees.

Lee, my husband has a subsoiler that is attached to the tractor and it is just an arm that you can adjust for how deep you want to go. You run the tractor around, with the subsoiler lowered and it "snags" roots and pulls them to the surface. Most roots will break off. That's how we put our garden in to begin with. We never plowed the soil in any way, we just ran the subsoiler around. I got a very nice pile of roots that are  aging to the side. It seemed invasive to me but a quick fix for lots and lots and lots of roots. I see that there are people who do this as a way to avoid that turnover of the soil but still get some nice dead roots in there to feed the plants that go into the garden. I am constantly amazed at the wealth of wisdom, experience, and help that people give who love the soil!

Lee Missouri wrote:How do you do root plowing? How do you balance cutting the roots with keeping the tree healthy? I've pruned trees and saw great improvement in their health, but I've never heard of doing something similar with the roots.

I believe the plows at the FSA offices are sharper and intended to cut roots without ripping them out. I have not used one. I believe they rent them cheap. The subsoilers I've seen had a narrow but flat point instead of a sharp edge. A subsoiler should work. I'm not sure if they can run as deep.

Mark Shepard uses something like this and recommends it, about 0:56 on this video for alleycrops.

Makes sense.

Lorraine Barnett wrote: There are two trees (small persimmon and another ?? maybe 25 feet tall with small slender trunks) that are left nearer the garden on the north side. My husband wants to cut down the two trees but I'm not wanting to do so. Can these two trees be sapping away all the moisture and nutrients of that end of the garden? It seems unlikely to me but I'm puzzled. Any ideas?

Cutting persimmon trees? Persimmons are a slender tree, so their roots are unlikely to be the problem. I think Marcos hit the nail on the head. Mulching heavily will keep the moisture where you want it. Who knows? You may even discover that your persimmons become a very desirable tree. In Central Wisconsin, it is too cold to grow them, but I've tasted some from Tennessee and they were really good. I really wish I could grow them here. Assuming this mulch idea does not pan out, [it will, but just playing devil's advocate here]you will still have a greatly improved soil and you could cut those trees and enlarge your garden.

More mulch may help a lot more than you think, if you add enough of it.  I have a squash patch that was sited literally under the edge of a patch of scrubby brush and poplar forest.  There are a couple of trees growing right in the patch, and several more along one edge.  It started out as the dump pile for manure from the barn, but after a couple of years, we leveled it and started planting squash there, just to see what would happen.  When we started, there was probably a couple of feet of partially composted straw and manure (it has rotted down since, and even with additional straw we've thrown on it, is probably 8 inches or less now).  We live in a very dry area, and don't water the garden, so that spot should be really dry and hard to grow anything in.  However, it has been very productive, and in particular, the straw soaks up the moisture from snow, and holds it there, rather than allowing it to run off the frozen ground in the spring, which is what happens on much of the rest of our yard, allowing us to capture and retain water that we otherwise wouldn't be able to.  

What I'm getting at is that even if the trees are sapping moisture from the area, a very deep pile of mulch will hold additional water beyond what would otherwise have been there, and allow you to grow some plants in that area (plus improve the soil).  Squash seems to do particularly well for us in deep mulch, though we haven't tried many other things in that spot.  You could try a compromise with your husband, where you try a deep mulch for one or two years, before agreeing to prune / cut down the trees.  

There are some very good and insightful replies in the string so far. I'd like to add one perspective.

Consider SUCCESSION. What you are trying to do is go "backward" in the natural order of succession wherein bare ground is colonized by first pioneer annual plants,
then perennial shrubs and climaxing in mature forest. So we want to acknowledge this and keep it in mind. Next, we want to think of the bacterial:fungal ratios of your soil.
In forest, you have a fungal dominant soil; yet in thriving garden you are looking for a more balanced bacterial-to-fungal ratio (and for cole or brassica crops, bacteria dominant
soils are preferred).

If you're not familiar with these concepts, Elaine Ingham's work is a great place to start: www.youtube.com/watch?v=x2H60ritjag

Shifting the bacteria-to-fungal ratio may be a key factor in creating a thriving vegetable garden in your situation. I believe Native American practice of controlled burns may be one
method to consider, and of course "tilling" once (or once every 5- or 10 years) might also accomplish your goals as soil disturbance favors bacterial selection in soils.
Applications of bacterially-dominant compost would also be key, as well as boosting organic matter to feed those bacteria. Of course, tree health will decline where soils are disturbed
and infused with greater bacteria counts. You may find that the transition/border (EDGE!) of your annual garden is a good niche for planting perennial vegetables.

I think it is also worth considering the health and happiness of the trees. If the forest floor is deeply mulched in leaves & twigs & fallen rotting trees, the trees will have less
need to be seeking out the garden's moisture. If the garden has a thriving, balanced soil ecosystem, it will be more drought tolerant and less in need of additional watering.
This has been my experience in a semi-arid climate (Utah, 4,900' elevation, 17" precipitation annually).

There are multiple ways to approach it, and this is an exciting chance for you to experiment, try various methods, and report back what is working and what is not.

Before you use a subsoiler that just chops the roots into pieces and leaves them in the ground, check to see if your trees are the kind that will regrow from just a chunk of root.  I've got a bunch of black locusts in the area I plan to use for a vegetable garden at our new house; they spread by suckering from the roots, and I strongly suspect that at least some chunks of root left from subsoiling around them would probably grow.

Mid Missouri, I have some experience with that.  The suggestion that mulch will help is a good one.  Adding organic matter always will improve clay.  But, there is another factor at work. The bed rock here is dolomite.  It's part calcium and part magnesium and it has been leaching into and out of the soil for the last 1.5 million years.  The calcium is more soluble and is leached out of the soil more easily.  It is also taken up by plants in greater quantities.  The result is a build up of magnesium in the soil.  This will cause the clay to become harder. But, it can be undone by adding calcium.  If your pH is low and you want to raise it, lime will fix both problems.  Be sure the lime is not made from dolomite as this will not change the mineral balance.  If the pH is ok, gypsum will loosen the clay.  

I have not used a sub soiler myself but I have seen the results near Oaks and Hickories.  It seems to help a little.  I would not be too concerned with it harming a Persimmon as they have a taproot and a very deep root system.  They are also prone to growing multiple trunks from a common root. If you are not getting any fruit, you might have only one tree and no pollinator.  

If it was me,  I would be sure there is water flowing into the area,  then throw some gypsum at it,  add mulch and plant a persimmon guild.  There are recommendations  online for what to include in such a guild.  (If you really want persimmons you could find someone locally with a Yates Persimmon in his back yard that would give you a scion).

Uh, one of the goals of permaculture is to help natural forest succession establish a food forest of mature, perennial fruit/nut trees - LIKE persimmon trees!  Generally, you don't deforest and cut down perennial crop trees to help annual veggie crops grow!  That's backwards and knocking your system back decades in time!

You'd be much better off just spacing and layering down to your veggie garden a few more feet away from the forest edge, instead of cutting down good trees that took at least 7 years to grow and bear fruit.  And if they're male trees, I'd say they're still useful as pollinators and just high-quality, native trees with very hard wood.  That also produce a lot of leaves, which create the best topsoil.

Max Lee wrote:Uh, one of the goals of permaculture is to help natural forest succession establish a food forest of mature, perennial fruit/nut trees - LIKE persimmon trees!  Generally, you don't deforest and cut down perennial crop trees to help annual veggie crops grow!  That's backwards and knocking your system back decades in time!

You'd be much better off just spacing and layering down to your veggie garden a few more feet away from the forest edge, instead of cutting down good trees that took at least 7 years to grow and bear fruit.  And if they're male trees, I'd say they're still useful as pollinators and just high-quality, native trees with very hard wood.  That also produce a lot of leaves, which create the best topsoil.

While it's true that one of the goals of permaculture is to establish a food forest, there is usually also a need for at least some annual vegetables, not all of which can be grown successfully underneath, or too close to, trees and their roots.  It isn't always possible to move the vegetable garden farther away from the trees -- some lots are too small (and the trees may belong to a neighbor), and some already have too much tree cover.  

Kathleen

I strongly recommend all who believe a tree to the north of a garden in the northern temperate zone is harmful to read page 140 of the designers manual and preferably the whole chapter. Then read and observe your ecology and how forests cooperate as much as compete. Then if you disregard this information, still calculate how much you can get off a persimmon tree relative to its supposed cost to your garden. Trees increase the aggregate of water delivered to the soil beneath them and distribute it more evenly over time. This is integral to understanding their natural function. I am glad you are standing up for your trees!

from my own experience and observation, once the tree has established itself, it will assert it's claim over all ground above it's root mass.

it will resort to sapping moisture & nutrients and will release enzymes that will deter the growth of new vegetation.

if you want to use the space beneath your trees, you're best off with container plants.

I'm really grateful to all the posts! There is much to think on and I need to do more research so that I'm not working against the natural order. I still have much to learn about permaculture. I'm so intrigued, the more I read and digest. So often, I find myself saying "Of Course!!" It makes sense, once it is explained so that I can understand it. Thank you so much, Alex, for the suggestion of a Yates persimmon. I had despaired that any of the larger persimmons would work in my area. I may just make the Yates part of my plan! I also looked up Elaine Ingham and she is a wealth of soil knowledge! It's a bit more than I can wrap my mind around right now but I'll continue to listen and learn. Thanks, Jeanne, for that suggestion.

I can see my persimmon (which now I'm convinced I'll give another few years, at least) as part of my garden plan. I'm now wondering about the perennials that I can make part of the guild around the tree....that won't just be just fodder for the deer and coons... I have a pile of much that I will make part of the plan as well.

I'm excited about all this now, instead of just frustrated! Thanks to all of you!! Such thoughtful suggestions!

pusang halaw wrote:from my own experience and observation, once the tree has established itself, it will assert it's claim over all ground above it's root mass.

it will resort to sapping moisture & nutrients and will release enzymes that will deter the growth of new vegetation.

if you want to use the space beneath your trees, you're best off with container plants.

Some trees, like walnuts are allelopathic and will in a way "poison" the soil for some other plants. Apparently, barnyard grass and alfalfa do not grow as well under a persimmon:   http://agris.fao.org/agris-search/search.do?recordID=KR2005009146
but perhaps, many other things could. I would try strawberries. It is true that if all else fails, containers of anything will be better, sitting atop of some mulch, but container gardening has costs and adds to watering chores.

Ben Zumeta wrote:I strongly recommend all who believe a tree to the north of a garden in the northern temperate zone is harmful to read page 140 of the designers manual and preferably the whole chapter. Then read and observe your ecology and how forests cooperate as much as compete. Then if you disregard this information, still calculate how much you can get off a persimmon tree relative to its supposed cost to your garden. Trees increase the aggregate of water delivered to the soil beneath them and distribute it more evenly over time. This is integral to understanding their natural function. I am glad you are standing up for your trees!

What is your explanation for the picture that Joseph posted?

Cécile Stelzer Johnson wrote:container gardening has costs and adds to watering chores.

worth spending time and money on after losing so many upplanted squash, tomatoes, eggplant, cucumber and bell pepper plants just the other month.

pusang halaw wrote:

Cécile Stelzer Johnson wrote:container gardening has costs and adds to watering chores.

worth spending time and money on after losing so many upplanted squash, tomatoes, eggplant, cucumber and bell pepper plants just the other month.

I feel bad that you lost so many yummy plants. What did you lose them to and how would the containers have helped?

Cécile Stelzer Johnson wrote:I feel bad that you lost so many yummy plants. What did you lose them to and how would the containers have helped?

as you can see from a message i sent to a friend, i totally agree with some trees being allelopathic:
"most of the stuff (if not all) i transplanted under trees failed miserably. i wasn't entirely convinced before but i am now: trees react by sending deadly hormones and enzymes to the soil whenever root space is threatened."

here's the casualty list:
underneath a Pouteria Campechiana: 2 tomato plants, an eggplant and a squash.
right beside a 7' Gardenia: 2 squash.
between a large Avocado and a large Moringa: 3 tomato plants, 3 squash and a cucumber.
underneath two Bilimbi trees: a tomato plant, an eggplant and a squash

i already had serious aphid problems on the tomatoes and bell peppers but the squash, eggplant and cucumber all were healthy but died within 7 days.

none of the potted ones i replaced the casualties with have died so far.

pusang halaw wrote:

Cécile Stelzer Johnson wrote:I feel bad that you lost so many yummy plants. What did you lose them to and how would the containers have helped?

as you can see from a message i sent to a friend, i totally agree with some trees being allelopathic:
"most of the stuff (if not all) i transplanted under trees failed miserably. i wasn't entirely convinced before but i am now: trees react by sending deadly hormones and enzymes to the soil whenever root space is threatened."

here's the casualty list:
underneath a Pouteria Campechiana: 2 tomato plants, an eggplant and a squash.
right beside a 7' Gardenia: 2 squash.
between a large Avocado and a large Moringa: 3 tomato plants, 3 squash and a cucumber.
underneath two Bilimbi trees: a tomato plant, an eggplant and a squash

i already had serious aphid problems on the tomatoes and bell peppers but the squash, eggplant and cucumber all were healthy but died within 7 days.

none of the potted ones i replaced the casualties with have died so far.

Do you normally have these results only under that tree? or do you have similar results elsewhere in your garden? Unless your garden has a soil that is just not favorable for these crops, this does reinforce the argument of companion planting. Some plants/ trees do not like competition. Others not only live but prosper when planted with their "companions".

To clarify my previous post, I was specifically talking about water. Trees will chemically alter the soil beneath them to select for symbiotic plants, but almost all dominant tree species have native edible associates in the understory. They also enrich the ground below, but largely with tannic acids that require fungus to break down. I would also not dig into an established trees root zone.

Great to hear you are keeping the tree, I’d be interested to learn from your experience with what works under persimmon. I have seen decent success under my small young persimmon with strawberries and fava beans.

My experience with persimmons is in conflict one of the posts.  I dig up a lot of persimmons and I don't find big taproots.  I find extremely long roots running great distances from the trees and putting up suckers at many places.  Are you seeing volunteer root suckers coming up in your garden?  I graft Asian persimmons onto many of my persimmon saplings here in zone 7.  If you cut your persimmon trees off you will probably get a sapling come up that you could graft onto.  The Asian persimmons don't get near the size of the native persimmons.  The other thing to consider is the history of the soil.  Top soil in a mature forest is not very deep.  Most of the biomass is in the tree canopy.  A savanna with a mix of trees and grass will have much deeper top soil.  Your hard concrete soil may have been in a mature forest while the other areas not to far away may have been a savanna and have much more topsoil.  Mulch and cover crops is what it will take to build that soil.

My small but growing understanding of real permaculture makes me think your suggestion of mulching and cover cropping is the answer to this dilemna. My new mantra is "a living root." I am trying to keep the soil in cover crops as much as is possible...the deer have sheered off everything I've grown this fall but I'm believing there might be some roots in there somewhere! ;-) I will certainly look for suckers from my persimmon. I'd love to get an Asian persimmon grafted onto some of the suckers.

Looking forward to spring and trying some things to see how this garden fares!