Field growing -- pointers?

Please do send it along! I’d love to see it. :slight_smile:

1 Like

Does anyone remember the name of that plastic pot to use when field growing material? I have 3 black hills spruce that I want to do an experiment with. One on gravel in the nursery container, one in the dirt and one in this pot if I can remember… thanks in advance!

Are you thinking of an Anderson flat? its a shallow plastic square pot with a bunch of holes in the botom

1 Like

@Muchas_Plantas thank you so very much! That’s exactly what I was thinking about. The nursery should have these in stock? Have you purchased any before?

@hierophantic just interested on your thoughts regarding soil substrates. Let me know.

Great work field growing! Here’s some of my handy work doing the same. Been at it 10 years, let me know if you have a specific question.

I originally use the soil on our land with compost mixed in and now I have soil that hard to dig and fewer fine roots than I’d like. Use the combo mentioned in this thread and in the podcast. If plants are spaced appropriately I don’t see need to divide with material and if you use grow bags, which I highly recommend, you’ll spot large roots from crossing into the neighbors rootage and you’ll split that large root into many fine roots (as happens when using a root control bag). Pro Tip: the fine folks at High Caliper will let you order whatever quantities you need despite what the website says.


Oh shoot, that’s another ground growing thread. Here’s the one I meant to link to: How to Ground Grow the Telperion Way

1 Like

And here’s a post on reddit I made before I found Mirai Forum, check out those trunks!


Are you thinking about Rootmaker pots? I use them - they’re excellent.

1 Like

Search for the thread entitled “Field Growing results #1” - excellent thread.
I planted two Japanese maples (grown for 8 years from seedling) in the ground 3.5 years ago (no special soil), forced the roots to grow laterally by placing clay tiles underneath. Both maples grew to 7’-8’ in height; trunks thickened much quicker than those I potted. Did my first chop of both trees late last summer/early Fall when tree was fully leafed out. It was painful cutting off 6’+ of tree.

They wintered well. Both trees have leafed out well this spring/summer and are growing again, albeit more slowly. Will allow them free growth for another year, then possibly chop again. Rewarding but slow process. Here are some pics:

1 Like

Hi folks! ALL of you are heroes. At this point, I’m looking at raised beds done exactly according to @putitintheground’s thread here: How to Ground Grow the Telperion Way

I’m waffling between expanded shale and pumice. Cost will be a factor. I expect to put 8 trees in the ground in my yard to see how it goes (zone 8A): 2x nejikan poms, 1x full-size non-nejikan pom, 1x bougainvillea, 1x silver maple, 1x Chickasaw plum, 1x crape myrtle, 1x bald cypress. We’ll see how it goes!


Two follow-up questions (perhaps @putitintheground can help?)

  1. I’m planting trees that are currently shohin-sized and are intended, in the long term, to remain shohin-sized. What sized grow bags should I use?

  2. I have roughly 1 square foot allocated per tree. Should I be allocating more? Less?


1 Like

I’m just getting started with this, but I guess I can apply what I’ve learned from gardening in general. I always fall back to “what are you trying to accomplish?” said in Ryan’s voice lol. With field growing it’s kinda universally done for trunk thickening. That doesn’t really speak to trying to achieve a tiny root mass to fit into a tiny pot. You won’t even be using the type of soil required to make the fine root system required for that pot. You will have to keep in mind that you’ll eventually need to train the roots into a smaller pot. I’ve not tried this myself, so I can’t really speak to that, but a root bag tree grown in the ground won’t even be ready for a small bonsai pot. As far as sq footage goes that’s going to be up to you. Smaller sq footage equals smaller root bag equals less room for the roots to spread equals less growth when compared to same plant in same environment in a larger bag.

Here’s the thing, you’ve got time. Tons of it. You’re going to need to dig up the bag in a couple of years anyways. If you want to maximize your space then cram them in. If you want to maximize potential size then don’t. I have a way of over simplifying things though haha. If you cram now and find that in a couple of years you can get rid of some or transition them to pots then you’ll have freed up space to put others into bigger bags. Personally, I’d probably vary the sizes to have multiple goals even if all of the trees were the same type of tree.

Anyway, I’ll post what I’m currently doing in my next reply…


So after listening to the Telperion episode like three times I decided to take the plunge and try my hand at growing some trees in my yard. I ordered five 14" base bags from the same company that Telperion orders from. I can post a link if need be. I had some pumice sitting around which I used to mix with some “top soil” from Lowe’s and mushroom compost. Don’t like the idea of poop compost lol. The Lowe’s top soil is more like bark compost than anything else. I mixed this at a 2:2:1 ratio of pumice, top soil and mushroom compost.

I mulled over what to use as a barrier in a bag this size. My initial thought was to use cheapo ceramic or plastic plates from Walmart. Sadly all they had were 10" plates which I thought would be too small. I went over to hardware and bought some bucket lids instead for $1.50 each. They’re 12" lids which was perfect.

I filled the bag about 2/3 of the way up with soil, mounded a bit in the middle and then laid a lid on top of the mound using a twisting motion to get it to settle in nice and flat. Pulled the super root bound bald cypress out of their pots (also from Lowe’s at 50% off which ended up being $25 each) and pruned the course structural roots. I want the nebari to form on a flat base. Not the twisted mess in the pot.

I planted both in the ground. However, I made a poor choice for one of them and planted them in a spot that accumulates a lot of the rain/irrigation water. I’m in the process of moving it now, but it did give me the opportunity to take a picture of the tree in the bag and not in the ground. The other tree may have been buried a bit low? I had to top off a bit with about an inch to 1 1/2" of native soil. When I move the second one I’ll leave it a bit higher which will also give me the opportunity to observe the root development at the surface.

A third bag will be used to thicken this hinoki. Pardon the pic. I’ve set a single structural wire just to set the initial movement in the tree. Last night I removed branches that could lead to structural flaws while it spends its time in the ground. The pic of the partially filled grow bag is the bag for the hinoki. If you look carefully you can see the bucket lid. Sadly, I’ve run out of pumice, so I’ll be using diatomaceous earth sifted to between 1/8" and 1/4"…I’ve not seen much 1/4" DE though lol. Hopefully that will work out for me. I’m going to empty the bag, put the DE mix on the bottom and use what’s in there now (which has pumice) for the top section just because I want pumice in the area that will form the eventual root mass that will be potted.

I’ll be planting the hinoki and the other bald cypress this weekend. I’ll post pics of both when I’m done. Please feel free to tell me what I’m doing wrong lol.


Okay, one more question:

Assuming I’m planting in the Telperion-preferred root bags: if it turns out I won’t be putting them in the ground for a few months, can I slip pot into the root bags and keep them aboveground until I’m ready to plant?

I believe that should be okay if you aren’t really messing with the rootball.


Went ahead and planted the bald cypress this evening. Dug the hole several inches wider than the bag to make it easier to back fill. Wasn’t smart enough to do that with the first bald cypress. :frowning:

Here’s another pic of the hinoki as well sitting in the bag.

1 Like

I prefer 18-24 inches between trunks but I have a large yard to work with. Once the branches start running I find closer spacing shades out lower and interior branches on the tree next to it. I wouldn’t go any closer than 12" and would only go 12" if I wasn’t planning on big growth and a long time in the ground.

Size root bags, probably the 10-12" would be good. The 12" Telperion uses even for trees that grow very large. What are you trying to accomplish is a great question. If you are trying to achieve trunk thickening then you are trying to achieve trunk thickening regardless of the end size of the tree. You achieve trunk thickening by letting the tree grow out and accumulate vascular tissue. So if you’re trying to go from a #2 pencil to a salt shaker diameter base you will need to grow the tree out and cut it back down. So if you put it in a small 6" bag it will not grow as fast as in a 10-12" bag. The roots mimic the branches so your roots will run out as well and may need to be pruned back over a series of repottings before it is ready for a shohin pot. as @Bonsai_Bentley correctly states. Note: Grow bags do not stop root growth from penetrating the bag, but it splits the bigger roots into fine feeder roots.

I would also worry about a 6-8" bag being shallow with a tile in it being even shallower and then the tree potentially drying out faster depending on where you live.

Ground growing requires growing out bigger than you want and then coming back and cutting back. I guess it’s not all that different than pot growing if you listen to Ryan’s videos about growing beyond and then reducing back.

1 Like

Very good point about spacing for growth. An easy aspect to miss when the focus is what’s going in the ground.

1 Like

I was contemplating this after planting the second bald cypress. I was look at its current leader and decided that I’m going to need to let that run in order to thicken the trunk. However, the tree is already close to 7’ tall. My plan is to let it run until I feel like it’s gotten too tall. Then I’ll cut back to a new leader that’s still above my eventual desired height. Then when I get closer to wanting collect it I’ll cut closer (if not to) my desired height. The more I think about this though the more I realize that putting it into the ground was the easy part. :weary:

1 Like