Planting fruit trees in raised ground

I have heavy clay soil, and I plant all my trees on mounds. I make a hole (4x4 ft wide and 3 ft deep) and then fill it back with a mixture of the excavated clay, compost and gypsum. The ratio is approximately 1 part of gypsum and 3 parts of compost to 10 parts of clay. This creates a mound about 12-18" high on top of the hole. It settles a bit with time, but tree remains mounded. Based on my observations, the trees have no problem growing their roots into the native soil (probably, because in my climate clay contains more moisture in spring and roots follow the water). I buy compost by truckload from my city (the price is currently about $250 for 20 cubic yards, including delivery).

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Potting soil is usually mostly peat moss which is organic matter preserved by a high acid-low oxygen bog environment. The pH is raised with lime to make it suitable for a wide range of plants and perlite is added, which makes it very unstable as it quickly breaks down into humus vastly reducing its volume (and its ability to aerate). I’d make my mounds with a mixture of sand and compost or a light (sandy) natural top soil. Much cheaper and much better suited for your purposes. Potting soil is for pots.

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Thanks for all the great information, so the consensus is that the mound is a good idea, but not using potting soil. Makes sense to me.

My house backs up to a creek, and there’s small bit of grade where the backyard runs downhill. I’m sure when these homes were built in the 90’s that they hauled in whatever fill dirt and sand in order to level area where the slab went…That’s why when we talk about native soil, I’m not sure if mine is native or part of the fill…

My neighbor recently brought in some dirt to level his yard for a new deck. It looks like he’ll have some left over. May see if I can get some from him and use that with a combination of soil in my yard and planting soil of some sort.

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Top soil is really just fill soil and has low organic material compared to compost or garden soil, so I would use that for any additional soil you may need. Plus you want low organic material in the mound. As Alan mentions a light sandy top soil is ideal. If you need more soil that is, an option that is easy to find too.

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For trees that don’t like wet feet, the first consideration is location. When it rains, does the rain flow to the trees or away from them? Are the trees on level ground? on top of a slope, in the middle or at the bottom? Does the creek overflow during heavy rain?

If rains/water flows to the trees, try to build something to divert it. Plant on mounds helps if the mounds do not sit in the middle of a drain pool when rains.

Peat absorbs water, a lot of it and it is usually the main ingredient in potting mix so that is the last thing you want to add. Compost is a common answer to amend soil but that also holds moisture so you have to experiment how much is too much in your case. Put some soil in a glass jar fill with water, shake it well, the first that settles is sand, then silt, clay and the rest floating is organic matter. Run a few samples to see what your soil is made of before you add anything to it.

When you plant on mound, you have to plant it quite a bit higher at the beginning anticipating soil settle in afterwards. How long it takes or how much to settle depends on your soil. You can build the mound in proportion to the size of the grown tree to accommodate further roots extension.

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Yes, true but we all do it for different reasons. It’s not wet where I’m at. I do it to keep trees planted at the proper depth, I can see better, and it won’t sink past ground level on the mound. If it does even become level with the ground, OK by me. I just don’t want it deeper where water can puddle.
Users here also have planted in amended holes and later dug them out to move and the roots stayed in the good soil only. It’s super important to use as much native soil, or worse as possible. Never better. See this thread.

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This is certainly true- mounds always settle more than I expect even though I should know by now. What I don’t agree with is all the concern about how much water the soil in the raised mound holds- as long as it is a mixture that drains well your trees should be fine, even if after draining, it holds quite a bit of available water. That will only mean that the mounds won’t need to be as large to support the trees. The nice thing about sucky drainage is that it limits root growth which actually improves fruit quality and calms down vegetative growth if there is a reasonable amount of well drained soil for trees to exploit.

Deep, well drained soil is often recommended for commercial orchards, but in the northeast its virtue only exists during extreme drought. On a normal year, shallow, droughty soil improves the quality of most species of tree fruit. Wine makers often talk about the value of stressing grapes to make fine wine- well that’s all about getting high brix and the same principle applies to fruit trees. .

Hi Drew, thanks for pointing out that thread. If I read it correctly, Sean put two trees and a year later found out one is root bounded because he mixed in Tree & Shrub soil for the root bounded one. He broke the “side wall” of the root balls to let the root grow out so they both supposed to grow out.

The result is interesting enough to try it again, probably with better pruning and spreading of both trees roots initially. Half & Half soil amend & the double size dig of your root ball is universally recommended by professionals so I am hesitant going against the conventional wisdom over one counterexample that seemed to be done in a hurry. If you also amend the surrounding soil and don’t just water at the base of your tree, the roots naturally go out seeking water & nutrients, it is unlikely to root bound in ground.

Jeremy lives in Florida and his problem seems to be heavy rain so drainage should be the priority consideration (location related) . If the “native” soil and heavy rain is bad for your apple tree and you want to plant it there, then, you have to make your “native” soil better drained and make the rain move away from the tree (soil amend & mound).

Again, you can test your soil with a simple percolation test before deciding what to do next. Dig a feet wide hole, 2 ft deep, fill it with water and let it drain, then fill it again and measure how fast it drain this time. 1-2 " per hour is what Oregon State U extension calls it ideal for apple trees. Check your local extension for recommended varieties and drainage rate if you want to be more location specific. You can also send in soil sample for test to see if you really need any amendment.

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How long before an apple tree mature? And how big would that be for a dwarf or semi dwarf tree? I am assuming Jeremy is not planning a standard size tree, which may be too big for home garden. The advice on fertilization is usually in a circle set by the outer rim of branches, where the feeder roots are.

To increase yield and fruit quality on apple trees, the advice is usually to thin the early fruits because apple is naturally biennial. And plant another variety of apple tree nearby for pollination or even crabapple to facilitate cross pollination.

Of course, before we get to improving yield and fruit quality, the tree’s roots need to survive all that rain and clogging clay soil. In poorly drained soil, root rots is a condition that needs to be fixed for the survival of the tree.

Wine grapes are pretty different from table grapes or other fruits because to produce exceptional wine, you need to keep the yield very low. We seldom try very hard to keep our other fruit crops low yield.

Wine grapes develop more complex flavor as they age and their roots extend deep searching for nutrients. The complex flavors and color come mostly from the skin, less so from the juice. We don’t grow table grapes for their skin or pay $13,000 for a bottle of fermented apple juice. Not every wine grape grower look for high brix. High brix or high sugar translates to high alcohol or big wines in wine speak. Not every varietal or region is suited for that style.

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Grasshopper, I don’t know why you debate me. I manage thousands of trees and am highly opinionated with opinions based on established research and my own anecdotes- I’m an old man whose entire life has been focused on growing things in soil- mostly fruit trees. The opinion I offer on higher brix is simply that relative brix of the fruit of every species I grow is a good indicator of relative quality- to eat- not make wine. Higher brix fruit has more sugar, but also, often, every component that gives fruit its taste.

I manage orchards in sandy soils, loam soils, clay soils, soils that are excessively wet, soils that dry out in just a few days after being irrigated or heavily rained on. Essentially most of the soils that have formed here in the northeast and a couple in the west many years ago. I even manage a few orchards that I’ve established with trees on individual mounds.

My opinions are not gospel, and folks on this forum have pointed out errors in my thinking on numerous occasions, for which I’m grateful. However, what I said about stressing the vine to make the wine is a throw away comment to be savored with some cheese. It has good character but perhaps the comparison of vines to trees is not to everyone’s taste. However, I think it may be legitimate.

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Well as far as I have read and understand amending soil with new trees is against conventional wisdom. I have never seen any expert say otherwise. It makes a lot of sense as roots can go very far and will make it to native soil, and you want that to not be foreign in anyway. I have seen some trees with roots over 30 feet long. I would say some exceptions exist, well I have seen one exception. The soil was so poor, that amending was the only way to grow trees.

I often debate you, but you usually win those debates, but I’ll keep trying! :slight_smile:

More conventional wisdom. I was told not to fertilize or even water. Brix for my grapes is 20 this year, first crop ever with Einset. I swear they taste just like my dad’s grapes except no seed or leather skin! Like the soil is doing it, what grapes taste like here, very interesting. The good news is the taste is exceptional, as were my dad’s grapes.

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I think we are actually more in agreement than not.

  1. When I said soil amend, I meant improving drainage, not necessarily using compost, and definitely not potting soil or fertilizing new tree.

  2. Alan and I digressed a little on the grape thing :smiley: Jeremy is trying to plant his apple tree in Florida at a potentially water clogged site, which is the issue we try to help him with.

  3. My suggestion was 1) Survey your location. Find a place that is less likely to collect rain 2) Test your soil either using the jar settlement, percolation, or send samples to local lab for analysis. 3) If you need to build mound, build one that is big enough so when the tree matures in 5 years, its roots are not sitting in the ditch nearby. 4.) Plant it a little higher depending on the soil. You can keep the soil compact right under the rootball to reduce sinking. Or you can amend the soil and then compact it under the rootball. Or you can plant it a little higher knowing it will sink quite a bit. 5) Contact your university local extension for specific advice on varietals and soil because they know your area best. http://edis.ifas.ufl.edu/mg073 e.g. Most of Florida is not cold enough for apple planting. You need varietals that require low chill hours.

I hope these 5 advices can help you get a bountiful harvest in a few years. :slight_smile:

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One of the things I’ve come to learn in trying to grow apples in Florida, is that it’s not going to come easy. I’ve had plenty of people tell me they won’t grow here, but that’s not true as my Dorsett Golden is thriving…

I’m all about experimentation and realize there will be losses along the way. It’s just the cost of doing business. My hope is with a raised mound I’ll be able to increase the survivability of the trees by keeping the roots form being waterlogged.

I’m going to try the 4x4 hole method backfilled with a mix of amended native soil and see how that does. I’ve got some apple seedlings coming along that might be good candidates for testing. Stay tuned.

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And how much precip the month preceding harvest? Too me, in well drained soil, it is mostly, or only, too much water that dilutes fruit sugar. So I guess I was careless with my use of the cliche- starve the vine serve the wine. On the other hand, I know absolutely nothing about wine grapes. I do know that even the fruit I grow responds differently to excess water. Doesn’t seem to hurt plums much.

Grasshopper, I think your advice is fine. I will say that if you build high enough mounds you can grow fruit trees in a lake, so you don’t have to think too much about using the driest patch on your property- especially if it is not the sunniest. I have successfully established orchards on sites with permanent standing water, believe it or not.

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3 inches depending where you’re standing. Largest rainfall at once was 0.9 inches. Smallest was 0.15 inches. That is for July when my nectarine were harvested.This month it is at 3.85 with a chance of one more rainfall Monday before the month is up.

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OK, if we call it an argument, you can chalk one up. 3" is a decent amount of monthly rainfall. Maybe grapes don’t react to too much water like my stone fruit. Let me know the brix when you get 6 instead of 3.

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That will happen. it took me a bit to find the most accurate info. I think this is fairly accurate now. I’m not always here and 35 miles away conditions are much different. Being on the water it is usually 3 degrees colder and rain patterns vary a lot to the weather at my house. So I’m not always here, maybe 60% of the time for 8 months. I remember one August where it rained almost every day. Russell island flooded, I never seen anything like it. We have since installed pumps around the island to drain it. I put one around my house too.[quote=“alan, post:21, topic:12341”]
you can chalk one up. 3" is a decent amount of monthly rainfal
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I got that wrong, for July it was 2.55 for August 3.85 so a little over 3 inches a month for the last two months.

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Jeremy, that is the spirit! Experiment and try out the possibilities.:+1:

Do equip yourself with the background knowledge:

  1. It is usually advised to plant more than one apple variety since most apple varietals cannot self pollinate and more than one variety will help improve fruit yield and quality for the ones that are partially self pollinate. U of Florida extension suggests planting Anna with Dorsett Golden because their flowering overlaps and both are well adapted to your region. Ein Shemer and Tropical Sweet are the two other varieties they tested successfully at their Gainsville station, which is not too far from you. These 4 require very low chill hours(200-300 I believe) compare to the 500-1700 of the northern varietals.

  2. As a result of cross pollination, apple seedling/seeds are not true to the cultivar. If you want a Dorsett Golden at that location, don’t just plant the apple seedling. You can, however, use the seedlings to test the ground and then later graft the Dorsett Golden scion onto it but that seedling rootstock may not have the characteristics of its parent, which adapted to your area. The alternative is to use D.G. cuttings, which should root just as easily in your area. However, you will end up getting a standard size D.G.

  3. Most apple trees are grafted on rootstocks. Rootstock selection determine how vigor, how big , how strong and how soon the tree bear fruits so it is not something you want to skim on. A quick search seems to point to M-111 as one that can tolerate wet soil and high soil temperature and let you prune it to dwarf or semi dwarf size. You can follow the various university rootstock research projects like the NC-140 or simply ask your local extension on which one to use for your soil and climate.

  4. Alan have a very good point about the rain near harvest, which is Mid June - Early July I believe for D.G… You get about 5.78 - 5.99 inch of rain during that period this year. Too much rain near harvest is going to affect fruit quality. I am wondering what else you can do to reduce the soaking during that time.

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All of us in the humid region wonder. Lighter soil certainly helps, but you will more likely need to irrigate during droughts.

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i also have rocky clay soil and plant in mounds. i use mostly native soil with a little compost and peat added. helps hold water in the mound in dry times. i also put a wood chip mulch 3in. thick around the tree. works good.

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