Soil depth and fruit and nut trees

Dreaming about retiring someday and moving to something larger than a 9000 square foot lot, I’ve done some browsing of real estate listings out in the “country”. When I find something interesting, one of the first things I do is look at the NRCS soil maps to see what the soil is like. Besides all the different soil types, etc. I’ve noticed that soil depth can vary quite a lot. Right now it is just idle daydreaming, but still enjoyable.

So how much soil depth do you need to grow fruit trees like pawpaws, persimmons, pears, and nut trees like chestnuts? If a soil profile lists bedrock at 30 inches below the surface, is that a problem? I realize deep, rich, well-drained soil is ideal, but can you still have a nice orchard if your soil is only 30 inches deep? What about 20 inches? I’m not worried about trying to grow the biggest trees, but if it slows them down dramatically or causes other problems, then that is obviously a concern.

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we have very thin topsoil here and fruit trees grow just fine. we average about 18in. of topsoil. deeper in the river valleys. thinner in the mountains.

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One thing you can do if you can’t dig down you build up; say you want to plant a potted tree, you remove the plastic pot, put the tree in the ground, and put dirt around it. No hole needed.

Find out if any of the trees you want have a strong singular tap root, they may not like your environment.

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Yes, a ‘simplified raised bed’…you can raise most any plant if you add enough dirt.

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i imagine you guys have even thinner topsoil up there than we do.

Depends on what kind of soil you have on top of the bedrock, depends on whether the soil is well drained, depends on how quickly water percolates through the soil, depends on what kind of “bedrock” you have, depends on your climate, depends on which specific fruit or nut tree you are growing and what its rootstock is.

There is no soil profile that is best for everything. You should pick out one specific fruit or nut tree and start working on that. Pears and chestnuts for example are going to have different limitations and different requirements.

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Thanks for the thoughts so far. I realize I can build up, etc., but I’m sort of hoping I won’t need to “fix” a place if possible, since it is enough work just planting trees. Some soils I see look good, but others aren’t that deep and I wasn’t sure how that effected growth, health and production. Here is one that I was just looking at that made me wonder if it was okay that the soils might be only 25 inches or so. Official Series Description - CHILHOWIE Series

I realize pH, drainage, etc. all come into play as well, and this one might be a problem just based on pH, but an actual soil test can tell that for sure. But the depth of the soils seems a lot harder to test for so I assume you mostly need to go by these soil surveys for that. I just wasn’t sure how shallower soils affect trees in general, assuming you aren’t trying to grow 100-foot tall oaks.

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I am not sure how you could tell for sure how good the soil is… or how deep the good soil is without going on site and digging.

For example my place has (in a good location) about 4 inches of pretty good soil… a loamy clay… but then it quickly turns into red rocky sticky clay. If you try and till more than 3-4 inches deep … tiller jamming boulders.

So here I build up.

It is extra work… and you are right… it would be nice not to have to do that.

I basically till up an 8 ft wide strip of dirt 4 inches deep and then rake it up into a borderless raised bed around 4 ft wide… (doubling my good topsoil depth) and creating a raised bed that drains well.

It would be a lot nicer to just dig a hole and plant but in most of my county you need to be in a creek or river bottom area to have soil like that. I am on a ridge top.

Good luck… i think i would go on site and dig before buying.

PS… with a tractor and disk and box blade… it is not all that difficult to break up the top 4 inches and rake it up into nice long borderless raised beds. I had a tractor back when we built our home back in 2001 and did that. Since then I have done it with a tiller and rake… yep much more work that way.

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I have mostly clay here, I don’t have dirt.

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Most places will need some work to get it into optimal range. My soil is 50% gravel, 50% rocks from golf ball to football size. “Just planting trees” takes me half a day per tree…

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This is definitely true, but it is interesting and hopefully useful to use the NRCS soil surveys to get a sense of what you might have before deciding if a place is worth considering and digging around on to see for myself.

I’m curious if you or others here ever looked at what the survey says for your place and if that at all seems accurate. I’m quite amazed how detailed they seem, so I’ve wondered how accurate they are. I would guess they are better in some areas of the country than others. From your description, it sounds like you have some kind of gravely clay loam or the like.
https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx

Absolutely. I’m just thinking that if I ever get serious about buying a place it might be possible to be deciding between a few places so I’m hoping to know enough about the different soils, soil depths, etc. to take that into consideration.

I’ll need to save my energy to put up a deer fence!

The bedrock serves as a transport for many unwanted things, and depressions in it harbors more. In addition it is a non-starter for nut trees with tap roots.

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I’m on the side of a mountain and it’s pretty much all rock and clay here. I grow everything and it has all done great. With exception of rots and such.

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The Chilhowie soil isn’t something I’d get excited about for fruit trees. However, it is well drained but slowly permeable. It’s also probably droughty given the shallow depth. That’s not a game changer since some dryness can enhance fruit quality.

Look at tree size and growth on areas that are forested. That will tell you a lot about what you can expect from fruit trees.

I’d rather have a soil that’s on the dry side rather than wet or excessively rich and fertile.

There are soils here that are 8 inches of clay loam over limestone. Some of the limestone is very hard but roots do penetrate some. You can grow good fruit trees on that with irrigation in a very dry climate.

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If you are free to consider many places and have some research time as Trev says you can either dig to evaluate soil depth and quality, or you can simply observe what is growing in an area of interest. No doubt the price per acre will be influenced by what you get, but also determine what other fertile resources are nearby that you might have access to. If you end up with a poor soil profile but you have good sun exposure, a good reliable water source, and good drainage, and you happen to to have nearby horse barns, chicken farms, or some other source of fertile resources, you can improve the poor soil with some work and a good plan. In the east water rights are not usually a concern, but your water quality and the investment to obtain it might be! So just be thorough with a good checklist and you should do ok.
Dennis
Kent, wa

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Yeah, sun exposure and drainage beats better soil. My soil is garbage, but on my sunny areas I probably get about 18 hours of direct sunlight.

I’m actually growing my tree holes over the years. That crap soil is so bad that roots don’t even penetrate into it. In the spring I enlarge them by cutting a foot wide ring at least foot and a half deep. By the end of the season new roots have taken residence in this real estate.

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