I’ll be ordering a few fruit trees soon - 2 peach and 2 persimmon - from Stark Bros.
They will ship the trees out bare root around mid-February. I’m in zone 7b, and this apparently when USDA recommends is acceptable.
Only problem is that I have very bad, hard clay soil.
I have never bare root trees yet.
Is it best to mix half and half my hard clay with a better soil for these trees? Or should I just exchange all the soil surrounding the tree with better soil?
Also, if you have recommendations for best types of soil for these trees I would love to hear them.
The problem with amending soil in heavy clay is that you can create a real water issue with the differences infiltration. Water will infiltrate amended soils much faster than clay. So, in the spring when you get ample rain, you can create a pond and drown your seedling. Then in the summer you have the opposite effect. Native clay can hold moisture when it evaporates much more quickly from amended soil so if you don’t provide supplemental water you can dry them out.
I have heavy clay soils and I plant trees on my farm that get no supplemental care after planting. This route is not for everyone but it works for me. I grow my trees from nuts and seeds using a root pruning container system (Rootmaker). I start with Express Trays (18s), transplant to 1 gal Rootbuilder II and then 3 gal Rootbuilder II containers before planting the trees at the farm. I use a professional mix like promix that is very well drained. This ends up forming a very dense and efficient root ball.
The containers unwrap so there is no disturbance to the root ball, but it creates an issue with the worst differential infiltration condition I’ve seen. I deal with it by using a tractor mounted auger to dig a very deep hole. I use an auger very slightly larger in diameter than the container I’m planting from. I hand rake the sides to avoid glazing. I back fill the hole with amended soil and even use quarry stone to ensure it is very well drained. I always pick a spot where ground water will not drain into the hole. Once backfilled to the right level, I insert the root ball. The top of the medium is about 1" above the soil line for settling. I then take the native clay and build a mound around and over the root ball and medium.
This approach reduces the amount of water that enter the hole directly when we get our ample spring rains. Any water that enters the hole drains below the root ball which is why the hole is so deep (several feet). This keeps the root ball from sitting in water. The reason the diameter of the hole is such that there is a tight fit is that lateral roots will enter the native clay by summer time. The clay mounded over the medium helps prevent water loss in the summer and since the lateral roots are in the clay which holds water well, the tree has access to water during dry periods of summer.
There are other ways to do it. I’ve know some folks who build mounds of amended soil and plant trees on the mounds above the clay. Some don’t amend at all and plant bare root directly and fill with the native clay. It all depends on your situation, weather, drainage, and soils.
No don’t amend the soil at all, If they don’t thrive then maybe, but all the problems listed are very true. I save local soil just to have extra for trees. The only accepted way to amend the soil is with mulch, as it breaks down. You can mulch with compost the 2nd year. Use bark, or straw, or pine straw the first year. Do not fertilize till the 2nd year, or after mid-summer if leafed out and growing. In 10 years anything you add will be long gone, if your tree starts on an amended mix, roots will girdle, bath tub effect etc, Bad news to amend tree soil. It will have to rely on local soil after the few years, so best to just start it in the soil it will live in.
Do not plant the tree deep!! The biggest rookie mistake! Mound the tree if possible, as it will sink some. I just barely cover the roots. If mounded and the roots begin to show, it’s easy to add more soil. If it is unmounded and it sinks, it will stay wetter, and could kill tree, The roots cannot breath either. At that point it needs to be replanted if you want to keep the tree. Deeply planted trees struggle very slowly, the stress makes them susceptible to borers, and canker infections. As the immune system is weakened. It is far from easy to grow fruit trees.Most think it’s the cultivar that is the problem or they got a bad tree, when it’s the way they planted the tree.
Here is a Satsuma Plum tree planted in June of 2015. So it’s going on 3rd leaf next season. It was planted on a 1 foot mound. The mound has sunk to about 5 inches. Which is fine! It is still mounded.
But that makes me worry about the (pottted)peach tree I planted back in Sept. I amended the clay soil with roughly 50% compost mixed in. After re-reading online recommendations regarding soil amendments, i realize those are referring to the whole area, not just the planting hole.
I made the hole 1.5ft deep by 2 feet in diameter, having considered the possibility of the bowl effect drowning my tree.
Should I dig it up and replace the surrounding soil with only native soil(clay)?
Or should I not worry so much and see how it goes?
I’d read the tree. The ponding effect can vary a lot depending on whether groundwater gets into the hole. I’d be tempted cover your amended area with some native clay to ensure water drains away. Next I’d cover the clay with air and water permeable landscaping material and then mulch over that. While the landscaping material will allow water to pass through it, it will limit it.
I think those are prudent steps. I’d then simply watch and read the tree. If it seems to be doing well, so be it. As the percentage of roots outside the amended area increases the tree will be at less risk. If the tree begins to look sick, then consider taking more drastic measures.
Keep in mind that life is pretty virulent. When we talk about not amending heavy clay, we are talking best practices that maximize your chances of success. Many folks don’t follow best practices and still have success.
OK, I don’t think the advice here is correct even if it is based on accurate information. First of all, you can amend a clay- and with more than mulch or compost. The books say not to use sand because they are talking about huge forest trees or amending large pieces of land. I’ve amended potting clay into a functional soil by mixing it with, by volume, 30% sand and 30% compost to create mounds.
I manage a 25 tree orchard where I did this with blue-grey clay and 12 years later it is one of the most productive orchards I manage- partially because the untreated clay is so inhospitable to root growth that the trees are somewhat dwarfed by being restricted to the soil I’ve created. Peaches required some extra work- I replanted them adding about 4 inches of pure compost and sand on the mounds and spreading most of the roots near the surface when planting. Pears, plums, apples and apricots grew fine from the get-go.
But all clays are not equal. You need to determine the rate of percolation to know how much trouble you need to go to in order to be successful. Often, in heavy soils, all you have to do is grow the trees on berms and mulch. I only incorporate amendments into existing soil in more extreme cases. I like to dress a planted tree with about 6 cubic feet of a leaf and wood based compost and mulch over that, creating an instant forest soil.
I’m in the minority as well but I amend my soil when new trees go in. That said, I like to dig massive holes that are 3’ deep and just as wide. I mix the clay soil I excavated with compost and top the hole back off. My trees (other than my persimmons) have thrived and when I’ve yanked poorly producing trees I haven’t seen any girdling. I attribute that to the size of my hole.
I’m not saying you can’t amend clay. I’m saying that the water infiltration differential between the amended clay and the native clay can be problematic. I recall an article by Dr. Whitcomb discussing problems and remedial actions for dealing with it. The problem is typically seen when planting containerized trees because the container medium is often much faster drained than the native clay. As you say, not all clay is the same and a lot depends on things like weather and drainage.
Yes, I know about amending planting holes, this is a different issue. When soil is not amenable to growing trees, drastic action may be needed. I’ve even established orchards in sites with standing water all year long- the mounds were about 3.5 ft tall. Trees grew great and never suffered from drought.
Whitcomb’s research has been around for a very long time now, but it is only part of the story. You can amend an area, just not a small hole. If there is adequate amended soil for trees to grow into for about three years after transplant, and if you amend soil above the poor drainage, it can work very well.
I don’t disagree at all. Biochar and other amendments can be use to amend larger areas in clay. I took the OP’s question to be about digging holes and planting a few individual trees rather than amending soil in a large area.
I tried to be clear that I was pointing out an issue with digging holes, amending clay, and planting a tree than need to be addressed. There a number of ways to accomplish that.
Well back at you brother, Seems some think you just gave the worst advise you possibly can give. You advised the OP to make concrete!
From the article
“The fact is that adding sand to clay soil in any amount is an extremely dangerous thing to do. You end up with something akin to concrete.”
Every expert I ever heard had said this exact same thing. [quote=“forestandfarm, post:12, topic:8349”]
I don’t disagree at all.
[/quote]
I do 100%. I’ll stick to the advice given by University of California Agricultural Extension and the U.S. Department of Agriculture never to use sand with clay.
Also the advise Jack gave is right on, and also mentioned in this article.
Again from the article
All soil experts will tell you one of the first rules of amending soil is “never tamper with the structure of your soil.”
Basically what Jack was saying, and you’re correct Jack! And what I said about amending using mulch, you do not disturb the soil structure amending in this fashion.
So why come here? Or maybe ask them a few more questions. Or experiment. You seem to be saying I should ignore my own experience and a very logical explanation of the limitation of the standard guidance. You have ignored that explanation, which is what I find annoying in your response. The difference between clay, loam and sand soils is almost entirely the proportion of each in any given soil, so obviously if you add enough sand a clay is no longer a clay- the key is how much does that take.
Go on, take some clay soil, mix it with the proportions of sand and compost I suggest and see if you make concrete. Take some photos. Otherwise your comment adds nothing to this discussion, because I already conceded that the literature conflicts with my actual experience- unless you delve a bit deeper. For most homeowner, and probably all agricultural situations, adding enough sand to transform a clay would be a foolish enterprise, it would be cheaper to bring in a few inches of more porous soil if you were trying to grow a nice lawn, for instance.
What makes my method difficult, is that it is hard mixing a clay soil with anything. It may be easier just to pile a different soil on top of it. But I have found transforming the amount of soil needed to grow individual fruit trees can be a practical approach. Over the years I have had to deal with hundreds of soil types for this purpose which is not an experience any of the U.C. Davis experts probably have or even consider. We all have access to the same research nowadays.
As far as turning clay into concrete, that is not something I’ve ever managed to accomplish. Maybe I should try it to save me the cost of my next bag of cement.
Hello, We have heavy soil here, called Vergennes clay, a brown clay, which cracks heavily in dry weather, and has the water table to the top in wet, with a 10 degree or so slope. I planted the orchard in the early 2000’s tilled manure and some sand in the top 5" of the soil in 5’ wide strips. The orchard grew well for about 10 years, until we got several years in a row with record rainfall over several months, About a third of the trees died from the roots drowning, even on the more sloped soil, with many of the others set back. So, I created raised beds in a planted orchard by using the back hoe to dig a 1’ deep ditch down the center of each row, sloping it with the tiller.
I would say if there is a chance the roots will be sitting in water, always mound, it is much easier to do at planting than after.
Adding sand to clay reduces the width of the cracks by providing fracture points in the clay (more smaller cracks), which I believe reduces root breakage as the clay cracks.
The KEY word in Plumhills post is “tiller”. You can take any
clay soil, and add peat moss and compost, till them all together,
and you’ll have a successful planting site for anything. I’ve done it
with rock hard red clay.
If your planting site is in an area that naturally collects water and stays
wet, you need to choose another spot.
Sorry if I added any confusion to the OP. The advice I gave was for digging holes to plant individual trees in heavy clay. When I said I agree with Alan, I should have qualified that. I agree that it is possible to amend clay soil over a large area. I wasn’t agreeing with the specific methods. I don’t know enough about those methods to comment. I do know that one can improve clay soils for farming by increasing OM. There are other ways to improve the microbiology by adding something like biochar which provides structure for microorganisms. There are issues with techniques for adding OM. Some till in things like manure but the tillage introduces O2 which speeds the consumption of OM so if one is tilling it in, a lot of OM must be used to overcome those effects. Probably the best way I’ve seed is to build OM from the top down. If heavy clay is compacted and one needs to till to relieve that, a one shot heavy addition of OM is probably useful. After that, using no-till methods and building soil by adding OM at the top is a slow process that can improve heavy clay over time.
That is about the limits of my knowledge. As for things like adding sand, I’ll leave that to others to address. I wouldn’t go as far as saying never disturb soil structure. There are times it is a necessary evil to correct something like compaction (which we cause in the first place by putting heavy equipment on clay when it is wet), but in general, I agree.
For a better understanding of soils and tillage, us laymen would benefit from watching some of the Ray the Soil Guys videos: [Soil Slake and Infiltration Tests - Live Demo in Ray's Soil Health Page on Vimeo] Start with that one and watch some more. Most are aimed at the large scale farmer, but the underlying principles apply.
I probably added more confusion than anybody. i worded that very poorly. I thought you were very clear, and good advice. My apologies to all for not being able to express myself well. I never meant to say that about your post. Alan’s advice too, he was not doing what I thought. I do the same thing at times. Not enough local soil around here for all the mounds I need.After reading that once you make concrete, that fixing it not possible, just be careful what you do to your soil.
I’m sure glad I have good soil. It’s mostly clay, but not so much to be a problem, just enough to be extremely beneficial. Clay is so rich in minerals.
The OP asked about the height of mounds. From my understanding 4 inches is the minimum, and no maximum exists. Most of mine are 6 inches after 2 years. I start them at about 15 inches. It settles that much, or does with my soil.
No problem Drew. If I didn’t enjoy the dance I wouldn’t take the bait.
What I want to know is if anyone has ever succeeded in turning clay into concrete with some sand- I thought ground limestone was a necessary ingredient!
It takes a very strong tiller to accomplish this, however. We have done it for individual plots with cultivating forks but it takes some work. Actually, incorporating ingredients into any soil is always a high energy endeavor and usually enough stirring is not done when people try to do it by hand and aren’t attentive. I’ve seen this with peat moss on sites where it was used for blueberries- but maybe it wasn’t wetted first.
Or create berms or mounds. Sometimes there is no other spot.
