One more poser on the subject of soil amendments: What about pawpaws? The descriptions regarding their preferred soil is not what I have to offer them. I picked up 3 units yesterday, container grown in ‘potting soil’ or something that looks like it; two healthy cultivars maybe 15" tall and a ~3 footer seedling. Pawpaw sites recommend deep, fertile soil with good drainage and lots of organics. If your soil isn’t like that then make it that way. Dig deep, amend freely, so the roots go down.
These are to be planted above a creek in kind of a ‘sandy/silty, not a lot of organic stuff, but not too bad’ soil.
I have followed the bare minimum approach on most of my trees, adding very little in a few particularly challenging situations. The pawpaw situation seems different…is it?
I just found this post and don’t have time to read all the contributions to it so if what I say repeats anything, I apologize.
Like Olpea I move a lot of trees, but having a nursery that produces several species and moving hundreds a year and dealing with most every kind of soil in my region, the experience thing probably exceeds my ability to absorb it all.
I read here how Drew has tried three times and had trees fail with fall planting of bare root trees. I’m wondering by what method because I don’t see what conditions at his location would create problems beyond what we have here during a particularly tough winter. Fall planting should almost always work with most fruit species if trees are healthy and grew well the preceding season and the soil is insulated with an airy mulch. Only mulberries have complained about fall transplanting and have been known to throw such a temper tantrum they kill themselves, but even with mulberries that is rare. Maybe apricots have suffered from it as well, but it is hard to know because they often die whether recently transplanted or not.
As far as adding amendments, the main trick is to avoid too much contrast in texture between the native soil and the amended soil. If it’s coarser, the surrounding soil pulls away moisture, finer and it may stay too soggy, which is the worst. The literature discourages amending planting holes but the literature sometimes misses the point. With big trees it is often not practical to try to improve the amount of soil needed for their roots, but fruit trees are relatively small.
The literature says not to add sand, but if you add a great deal of sand to not too much clay it can be just the ticket when creating planting mounds for small trees. I’ve successfully planted orchards in blue clay I could throw pots with by adding enough sand and composted manure so the clay was only about a third of the planting mound by volume.
I don’t deal too much with paw paws, although I grow them in my own orchard- but the soil is naturally suited for them. They are relatively small trees so you can alter enough soil to get them to grow if what is there is untenable. This is a rare thing in my experience. Usually in marginal soils i create a mound of compost mixed thoroughly (very labor intensive without a serious tiller) with existing soil, plant the tree a bit too high and dress it with another quarter yard compost and a third yard of mulch on top of that (6 ‘diameter ring). In general you get more bang for your buck the more the OM is on top, rather than mixed in. In poor drainage situations mounds are the easiest solution. I’ve planted trees where there was standing water for much of the year in 3’ tall mounds and they’ve flourished although annual very heavy mulching is required to keep them high.
I’ve done it both ways, heavily amended and not. My experience is that neither worked.
What worked was what the nurserymen told me: Put a bag of acidified cotton burr in there. I would also heavily mulch because Jellyman said to do that, and for 90% of us, mulching is beneficial.
I argue that this is an area where we should strive for mediocrity, not perfection. Why? Because it’s the percentage play. Are you of the “bathtub” school of thinking? Then a bag of cotton burr ( or whatever amendment is suited to your area) isn’t going to bathtubify your soil. Are you of the point of view that we should amend the first year or two of root growth area to perfection? Then a bag of your area-appropriate amendment will at least keep things together on that front.
80% of optimum is pretty darn good, no matter if you approach it from one extreme or the other.
PS. please don’t quote random ag school literature to me. I don’t live at the University of Iowa research farm.
PPS I live in an area with heavy, adobe-like inorganic, not particularly fertile soil. Not caliche soil, which is actually associated with some surpringly fertile soil. So there is some logic to the area conventional wisdom.
InfiniteFruit
I will be the brave one and ask what is supposed to be wrong with the root system of the tree in the pic?
Did i miss something? I don’t recall seeing any random ag school literature in this thread…
Lots of very interesting info here Alan, Koko and others. A little update: once I unpotted the two cultivars I found little root clumps…well, here’s a photo of one:
I found little root clumps obviously from (barely) 4" pots cleverly hidden inside the large, 3 gal containers. Repeated correspondence with the owner revealed that he has no problem handing out little trees with little roots in big pots at big pot prices. Back to amendments: I dug medium/big holes and added a little composted manure and a little ‘planting mix’ so I took a middle-of-the-road approach. Mulch…I gotta mulch everything. The ground drains well enough there that that shouldn’t be an issue. It does flood there, as in running water, every few years, but only for a day or two, and when the flood is gone the water is gone; it’s a little higher right there than the surrounding area. If these little trees make it over the next year or two, I doubt they will have a problem in my lifetime. Amazing info in these recent posts…I learn so much here.
It always comes up. As if horticultural conditions can be extrapolated in that way.
Consider my mind blown. If we can’t learn anything from research, are we supposed to rely on anecdotal evidence?
Relevant citations, controlled studies, and quotes from sourced material are always appropriate within discussions here, as can be related individual anecdotal observations. Each reader may weigh the value of those contributions according to his own circumstances.
The problem is, it is anecdotal evidence. The anecdote being the research station at a land grant University somewhere, where the land has been carefully culvated for a lifetime and therefore the result especially suspect.
It’s nothing like a scientifically valid survey or a description of a biological or chemical property that can be replicated.
This is an unorthodox perspective and I think a not very productive one. If one rejects horticultural research, how can one not reject all controlled scientific studies and be consistent.
Of course, all research and particularly horticultural research can provide evidence that leads to mistaken conclusions and I agree with your approach of using local information, but I’ve been making my living from the soil for over 40 years and I’m very grateful for information I’ve gleaned from research carried out by various land grant universities in this country, particularly MSU, Cornell and Davis (2 of the 3 are close enough in climate to be quite relevant). This doesn’t mean I take all their research based prescriptions as Gospel- not by a long shot. I simply think of them as professional suggestions and a notch up from the suggestions of an amateur.
The anecdotal observations of fellow fruit growers are also very useful- and also often mistaken. Matching other growers experiences, I’ve discovered many of my own false conclusions based on anecdote that turned out to be coincidental, and I’m sure Don Yellman would say the same thing if he was here.
Skeptical of research but definitely pro-science
Kokopelli, I am confused: Research studies involve both bench work as well as in the ground subsequent anecdotal evidence and results. That’s kind of the whole idea about a research station: Test it in the lab, on the bench in vitro, then stick it in the ground under controlled growing conditions (to try to remove as many variables as possible), and report the results in vivo. This doesn’t always mean the results will be the same in all growing conditions, and every research station states that caveat, “these are our results in our area, under our growing conditions.” You eventually have to get it off the bench and in the ground to test. What are you objecting to?
Well Hoosier and Alan, no unorthodoxy meant. I merely think that you have to not overread the results.
If the land grant University digs a series of similar holes at their ag station, plants similar sized and aged tree varieties with variously used amendment regimes common to the area and then assesses growth at say, the third leaf and concludes that the unamended soil does better, does that prove anything?
Yes, it does. It proves that on reasonably fertile agricultural land, amendments are unnecessary and probably counter productive.
I would more generally conclude that the research suggests that “full bathtub mode” planting approaches should not be the default option for the backyard grower. The assumption that it can’t hurt is wrong.
Now consider the homeowner on a house constructed over an undisturbed formerly fertile field in say, the San Joaquin Valley. The research suggests that he should plant in an undisturbed hole, of course. But what if the homeowner knows that the developer removed the topsoil and sold it? Should he just mindlessly stick his tree in a hole in the ground and mulch? Maybe, but I wouldn’t say that the ag station research is particularly supportive of the approach.
I don’t think the research supports either approach. Those two approaches may be the EASIEST option, but I think research supports testing the soil in a distributed pattern and then amending the entire area to the correct concentrations for your garden/orchard plan, then planting as desired.
My point exactly. We probably agree in substance- in realizing that unless the studies were done with the clones you are growing in the same soil the same year you can assume the possibility that your results may vary.
What I said about soil texture goes a long way to explaining the problem of dumping a foreign amendment in a planting hole- it’s about capillary pull of water from coarse to fine soil. As you seemed to suggest- if you can improve the soil where the roots will be growing instead of just where the severed roots are, you may improve survival and vigor of a transplant (if existing soil truly sucks). I think of about 2’ beyond existing roots as being the crucial zone. The regrowth of roots starts outward from where they are severed, not within the existing rootball so much. I believe that is the basis of the failure of amendments in a small hole to often improve results.
Well, yes. And the exploding of the myth that the full bathtub approach is always going to be a good option is a significant contribution by the ag schools.
But the dogmatic idea that you should never amend your planting hole no matter what your circumstances isn’t science. It’s, well, dogma.
Unless we happen to be planting in relatively undisturbed heavily cultivated land, where we should not amend at all, I’d say that the research counsels conservatism.
Well, I live in a lot like you’ve described, but instead of clay soil (which is rich in minerals), I’m on DG. Which has about nothing good in it, except it drains fairly well where it is not compacted into caliche, which, when dried out, is literally as hard as a solid granite boulder (and has faked us out more than one time in thinking that’s what we were hitting whilst attempting to dig holes). I NEVER amend any of my holes. What I do do, is amend on top. I dig a fairly large hole and well (probably about 3 times the size of the rootball). Back fill with my native soil, but leave about 6" empty on top at the edge of the well, and top dress with compost, manure, worm casings, then mulch. I take care to make sure the tree isn’t planted any deeper than it was in the pot, and err on the slightly higher side, with the well perimeter lower (and deeps, to accommodate amendments.) My trees do very well this way. I try to amend every year. I know my soils needs amending. I don’t think that anyone in my neighborhood doesn’t know this, and we have all varying degrees of gardening knowledge. I water at the drip line and beyond, which encourages healthy, broad root growth. My belief, and the current belief of ag stations here in S. California, where not very many ag stations have anything close to ideal soils, is it is better to have a tree get used to the native soil, and expect nutrients to percolate down from the top (as it would be by mother nature). My trees are all establishing very well this way, I’ve rarely lost one (and the ones I’ve lost were either due to my faulty watering, or phytophthora infection, endemic in my area). So, I amend, but only the surface, as nature would do with leaf droppings. My trees in really thin soil are all doing well. And, I know my soil health is improving, as I have seen a really large increase in earthworms in my yard. It makes sense to me to mimic what happens in nature. And that to me would not be amending a hole. I don’t think the current research says not to amend at all, but as MisterGuy states, test and know how to amend, and amend accordingly. I have little to no organic matter in my soil, so compost, manure and mulch are what’s needed. For me, I don’t need a soil test to know that, but others may need to test their soils to know specifically what to amend.
Well I think that’s appropriate. The take away for me from these studies is conservatism which is not ‘do nothing’
Putting a six inch mulch of compost and what not at the top of a hole you had to dig with the help of a jackhammer may not technically be an amendment, but it’s not nothing.
If you know that you have bona fide agricultural soil then I accept the findings; nothing at all except a berm and a plain (non-fertilizing) mulch.
Trees get most of what they need in the top 12 inches of soil anyway. They also self mulch and create a parfait of distinct soil profiles and sometimes very large trees thrive in very thin and shallow soils with a few inches of high humus forest loam- as in the tropics. Prairie soils tend to be much more homogenous and deep. When you place a layer of compost over existing soil and top that with mulch, you are mimicking a forest soil.
I would agree that at times if you want to try a certain tree species you’re going to have to amend soil if your soil is that poor. But I think in the long run the tree will ultimately fail. Even if top soil is removed, if your tree can’t grow in native soil, top soil there or stripped, it is not going to grow, or will be very dependent on mulch and feeding, if you mess up, skip a year, etc., the tree could decline.
As far as Alan mentioning the soil texture is so true. I have seen the bathtub effect with amended soil, not pretty! I had to dig the plant out! It was literally a bath tub. Mixing with native soil solved the problem. Luckily where I live the soil is fairly decent. The glaciers made sure of that.