I’m planting a few trees (Apple, Pom, Plum) in 4ft by 4ft raises beds because I’ve got poorly draining heavy soil. I’m trying to decide what to fill the boxes with… the local landscape supply place has regular topsoil and what they call a “garden blend” that seems to be amended with steer manure compost and some pumice and such… much lighter texture in the garden blend for sure.
Would you use one of these 2 for the purpose? Perhaps another option I’m not thinking of? Does it matter much?
Don’t know if this is much help… but I couldn’t decide either. I put in some of both. I figure either one is better than straight sandy loam. Although I will say top soil has been scarce around here.
Just use dirt from the yard, if you have extra. Top dress with compost and mulch. The elevation will give you enough drainage.
For annual vegetables, I would suggest some kind of planter mix.
Thanks for the input @bleedingdirt and @SpokanePeach.
I do have some native soil I could move over to the area… and the price is definitely right to do it that way. Let me see if I’m thinking About this right… the downsides of bringing in the outside mix that come to mind are
1)cost
2)hassle
3) maybe anchorage wouldn’t be as good in the light fluffy soil
4)clay pot effect… the mix being so nutrient rich that the roots don’t want to move into the native soil below
Are any of those the factors coming to your mind @bleedingdirt when you suggest going with native soil?
Thanks again for the input!
You can ;always amend the top with compost. as mulch. and whatever else you can put in. Like once in awhile I put wood chips or pine bark, Most years I mulch with shredded leaves (have to be shredded) and some fertilizer and cover with compost.
That comes to mind for me. Unless you have terrible soil, best not to amend.
i have the same issue with heavy clay soil so I’ve been doing the same . been using a good potting mix in the bed and so far they have established into the native soil with no issues. i also keep the bed mulched well.
IMHO, clay pot effect is only when you make a hole in hard pan clay with smooth sides. I’ve never seen it with just amended soil even in gray, sludge/clay soil. The amendments should be spent in a year or two and roots will travel outside.
Whatever soil you use, be sure not to put fine soil over coarser soil because the interface between the two stops the downward capillary flow of water- in other words, poor drainage.
When soil is limited, high organic soil may be useful in terms of bang for the buck, but at some point, a leaner soil is better for fruit trees because you are trying to produce sweet fruit and not tender, big leaves and very vigorous growth. Also, the organic matter in (moist) soil releases most N. when the soil is warmest in summer- for the purpose of fruit production, it is in early spring that fruit trees benefit from nitrogen (serves fruit instead of vegetative vigor).
So, generally speaking, one wants rich soil for annual vegetable production but leaner soil for fruit trees.
That said, if the quantity of soil is limited, I would want the richest soil possible for my fruit trees. The limitation of soil will accomplish moderate rather than vigorous growth in itself, once trees are established.
If you purchase soil and it will be limited, I might use the basic soil as sub-soil and the more expensive blend as the top-soil. The trees will anchor in the heavier soil and send lots of fine root into the lighter soil. forest soil tends to be a parfait with the top few inches being a light very organic soil that warms up quickly in spring and jump starts the growth of trees with a massive web of fine roots surging at this time.
I respectively disagree. If they started circling they cannot escape, and the end result is girdling.Which should take 5 to 7 years to find out one way or the other. When you lose older trees it’s a pain, but digging them up to see the roots is useful.I think if you make a very wide hole, this can be avoided. It is current thought, but I don’t have trees with wides holes that died that had amened soil who who knows? I’m lucky because I have bought top soil, and my native soil clearly is richer than the bagged stuff. So I often dig a hole elsewhere to harvest my own soil and fill the holes with bagged top soil.
I don’t think anyone is talking about digging a hole in clay and filling it with amended, lighter soil. Is that what you are talking about BD?.
I can tell you that I’ve seen trees planted with poorly mixed peat moss in small holes- years later clods of dry peat moss remained near the base of the trees, ignored by the roots and the digestion of microbes because water just passed the clods by without absorption.
Coarser amended planting holes are a mistake, even if they don’t lead to girdling roots.
Interestingly, I don’t believe I’ve ever seen a fruit tree killed by girdling roots. Stunting is another question and I’ve no idea how often fruit trees may be stunted this way. Given how often trees are bought in pots with circling roots, my assumption is that fruit trees most often overcome this problem.
I think the latest suggestions of wider holes is for this reason, the circling would have to be tight to be detrimental. I also have heard recently that the trend of selling potted trees is going to come back to haunt us. Many on this site have lost young trees, but little to no investigation as to why? .
I think I should clarify what I meant by amendments. I mean mixing compost with the native soil and ending up with a mound where you plant your tree on. The hole is large enough with scored walls. Eventually, the compost is used up and the mound settles to more or less the original grade. I’m not talking about fertilizers, peat, coco coir or any kind of planting mix.
Thanks for the thoughtful responses… very helpful.
I really appreciate the idea of being thoughtful about how healthy forest soils function naturally with an organic surface layer… great point and good food for thought @alan
