Growing Potted Bare Root Trees with Native Soil

I have a bunch of bare root trees coming in a few days that I can't plant on site until the fall. In the meantime, I'm planting them in fabric pots but I don't know what soil medium to use. Can I use the native clayey soil? I feel like that would help acclimate it to the site conditions before planting, but I've heard a lot about how that can cause too much compaction in pots. But these are fabric pots, so does that make a difference? I don't want to buy some manufactured soilless medium, but will if I have to. So, any advice and/or firsthand experience would be greatly appreciated!

(PS. I'm new here.)

Thanks!!!
Spencer

The answer is, it depends. Is the clay soil going to be able to support healthy growth, or will you need to be adding compost/cover crops for several years? Take a look around at what else the soil is supporting.

Usually you get drainage problems with clay soil in a pot, which leads to root rot. You can cut your heavy clay soil with bark fines, available at any Home Depot or similar box store. DON'T use sand, that's for making bricks! I'd probably go 50-50, but make a few test batches to see how fast they drain in a pot. If you have standing water after a few minutes, it's too slow.

My experience is that fabric pots only make your soil dry out faster. Yes, you will get some root pruning, which is helpful when planting out, but if your summers are hot and dry, you'll struggle to keep the plant hydrated. I bought 15 smart pots many years ago, ended up giving them all away. Of course, you can easily cut down on the water loss by putting them in plastic bags with a hole or three in the bottom. Hope that helps!

Thanks Jim. At this point I think I'm going to use a 50/30/20 blend of topsoil, aged horse manure, and aged leaf mold.

That should work great. Be careful with leaf mold, though, it can seriously impair drainage. I'd probably use it as a top layer.

I've had good results putting a few inches of coarse wood chips (ramial of course) in the bottom of a pot and then using whatever soil I have on hand in the top. Over the course of a growing season the level of soil in the pot shrinks (two or three inches). Still doesn't save them all from my habit of completely forgetting to water, but some of them survive. Without the wood chips, I can't keep a pot alive.

Casie, what do the chips do for you? Is that to conserve a bit of water? I always run a drip line BEFORE I set out potted plants, I've learned the hard way it's always best to have irrigation before potting up. Of course, that's in CA, where we get 5-10" of rain a year.

With that much media shrinkage, you must be using a lot of organic matter. I've tried a lot of mixes over the years, and the one I've stuck with for a few seasons now is mostly bark fines, a little compost, and some powders (wood ash, gypsum, greensand, Cal-Phos). I'm always looking to improve transplant success, though.