Field growing -- pointers?

Hi folks!

I’m looking at putting several of my trees (currently containers) into my yard for a few years. I’m planning to grow them on tiles. Any advice? Especially:

  • Soil composition?
  • What to use for tiles?
  • If they’re in raised beds, should I have material dividing them from each other, or – since they’re on tiles – do I not care?



Look for the Telperion Farms episode of the Asymmetry podcast. They give a ton of info. I listened to it three times.


Here is what I did. I’m in a raised bed too, and used root control bags. Soil mix is maybe 40% bark, 40% pumice and the rest is field soil.

I don’t know if this is the best or not. The stuff has only been in the field for about a year and I haven’t pulled anything out yet. Some things might be ready in one or two more seasons but the rest has quite a way to go.


I started my field growing area last year and added to it with more trees this year. Amongst other things I bought a quantity of bare root 4 year old Scots Pine and Japanese Larch. Some of these have been put in nursery containers and some into the ground and some as root over rock experiments.

The soil in this area is between 6-10 inches deep and then its hard core rubble so the roots are automatically limited to particular depth. I use the soil which is there and this is full of gravel anyway. Around some of the trees I have used spent bonsai soil as well but this has been the exception. I will probably use a shovel to cut the roots in a diameter of between 9-12 inches around the trees every 2-3 years. Some have had wire on the trunks to wire shape in this year and the larch and scots pine will be wired this fall or winter now that their roots are established.
As we suffer from pretty bad winds being so open on all sides, I am growing a hedge around 3 sides of this area and my house is on the fourth to help protect it. The whole area is under the shade of a large sycamore tree which means it gets early morning and mid afternoon sun to varying degrees.

These first photos are from the start of May this year

These are taken in last the last week. The area has become a bit of a holding area for this years collected trees, trees needing more shade and trees needing recuperation.


That’s awesome, @Twisted! I wish I had that kind of space. :cry:


Thank you SO much for taking the time! That’s an amazing setup.

What are you using for soil? Just regular field soil, a mix, …?

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I plant into my native soil. I am lucky I have sandy soil great drainage. I do not use bags. I shovel prune in spring And hedge prune a couple times a year as needed. I like to twist up junipers and leave the wire on. I get some nice results .


I’ll be using root control bags filled with a mix of 40% pumice, 40% bark compost aka top soil from Lowe’s and 20% mushroom compost. I got the idea from the telperion episode, but they use manure compost.

For a barrier I’m just gonna use cheap plates from Walmart. Someone here on the forum uses this thing called an ups-a-daisy and plugs the holes.

When my pumice comes in this Friday I’ll be planting a Bald Cypress and a Hinoki.

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Opinion on swapping out pumice for 1/2" - 3/4" inch lava rock? Not enough water retention, too big particle size? Or just fine?

What are you trying to achieve with the swap? What kind of tree? That particle size seems a bit large to me. Keep in mind that when you eventually dig it up and put it into a pot some of that soil is coming with it.

Good questions! Relatively small deciduous, all of them.

What I’m trying to achieve: pumice isn’t available locally (therefore expensive); lava rock is available locally (therefore less expensive). If the swap is a rounding error, I’ll make it, but my intuition is that it’s NOT a rounding error and I shouldn’t.

Fair enough. I’m kinda in the same boat, but I decided to buy pumice online. When i look outside though I see all kinds of trees that aren’t growing in anything special. They’re just trees. I guess it’s all a matter of what do you want the collected material to look like. If you don’t want to use pumice you can try using perlite. The only reason why we don’t use perlite in a bonsai pot is because it floats at first. That won’t be an issue in the ground. Although this goes against the notion of some of the soil eventually ending up in the bonsai pot.

If you have the space, time and $$ you could try using all three to see what happens.

Yup, that’s my pumice supplier. And really, for 40% of six Rootmaker bags, it’s like ~$60 of pumice – not nothing, but not punishingly expensive either.

I appreciate your thoughts and feedback!

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Wow @Twisted I love your area!

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I just use regular native soil which has quite a lot of gravel worked into it. On a few trees I have mixed this up with used bonsai soil but by and large it’s native soil. I am just making it up as I go along and experimenting, I have no real idea what is best!

The only real advantages I can think of in using inorganic soil in the field is it may help develop a better root system prior to collection and it should be definitely easier to transition conifers from field to container. (I am likely to bare root deciduous on collection)

Interestingly in one of the latest soil scence podcasts Ryan said the bonsai with the highest number of micro-organisms in them are the ones most recently collected which still have some field soil in the container. He didn’t say why this was and I think it would be difficult to do explain this with evidence. It seems logical to me that micro-organisms would prefer organic soils and native soil versus inorganic and this may have benefits on tree growth. I suspect you would have to fertilise the trees in inorganic soils as well, I haven’t felt the need to fertilise any of my trees yet and year 2 growth is far more than year 2.

This winter I am going to plant some bare root Hornbeam and Trident maples I will try and do an experiment to see which grows best between soil types.

If anyone of you guys have room and two of the same species why not experiment as well?

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Look around for a local feed store. You should be able to get 40 lbs of Dry Stall (pumice) for about $15.


Is this it? Hmmm, perhaps that’s not it. It looks like Stall Dry is diatomaceous earth.

No, that’s not it. It’s Dry Stall not Stall Dry. Looks like this:



I have a nursery stock hornbeam still in the 5 gal container and nursery mix, and a trident (diff from what I showed previously) that I will be planting in the ground by end of summer.
I’m planning on mixing granular humic acid, kelp, rock phosphate to organic soil (not sure what type yet, maybe miracle gro organics) and pumice.

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@hierophantic can you source expanded shale in exchange for pumice? I would also use finer particles rather than 1/2 to 3/4 inch.

I don’t truly field grow but I do allow roots to escape from containers and pond baskets to accelerate growth during development. It’s worked extremely well for me and usually use bark mulch/chips and pumice or haydite. Pumice and haydite are very similar in their soil properties so I interchange them based on local availability and price. I have an article that compares haydite, pumice, ash and versalite; I can send to you if you like but the forum thread wont upload pdf.

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