Regarding soil mixture and DIY grow boxes in Scandinavia.

Hello! I'm doing some research on soil mixtures at the moment to prepare for some potting. As I want to find a efficient, affordable and easily obtainable method of making said mixes I'd like to know if I can use any of these products for the task.

LECA pellets - Link here.


Prydbark which translates to ornamental bark. Thought about using a sieve to get the wanted size.


Also read about some people on a Norwegian forum that used cat litter which does not clump up with great success.


What type of "soil" materials do you guys use? What sort of a % of each type?


And now for the grow boxes I'm going to build. I've been looking to get ahold of a black "window screen mesh" that I've seen others use on their pots, to make the roots grow well and to stop root growth by light.

Like this! What on earth is this called in Norway and where could I locate it?



I will be having pines, spruces and acers to start with.

I'm from Denmark and I have only been into bonsai for a couple of years but I will share my experience anyway.

For soil mix I use Leca Safe (Link) which is leca pellets in the size from 0-4mm. I dont know if this is the same as the Leca pellets you refer to? This is the main ingredient in my soil mix but I have also experimented with adding cat litter(50/50) without any better or worse effect and mainly because I was out of leca. :)At least not in my limited time doing this. To the Leca Safe I then add coco peat but only a little dependent on how much organic stuff you want in your soil mix. I have never added any bark to the mix but I dont have alot of pines either.

As for the mesh I just use some platic mesh that i bought in Ikea (Link), its cheap and its easy to cut in the wanted sized. I also use it in my homebuild grow boxes where I clamp the mesh to the bottom of the box with a couple of support planks. Btw. the coco peat is also bought in Ikea but I guess you can get it at many different garden centres.

Hope this answers some of your questions.


Regards,
Henrik

Hey! That's great info Henrik! I'll definitely check out the Ikea Stopp, it's very cheap! I found some insect netting that might do the same trick in a store close by, so I'll check that out next Monday when I go there.

Leca Safe looks good and cheap as well, but is 0-4 mm a good size range? I've seen people sieve their medium from 3 to 6 mm? How important is the size of the pellets for it to make a good mix? As Leca holds no water, what's your % mix of Leca and e.g coco peat/cat litter? I can see a possible downside of using cat litter if I'm going to cover both the sides and the underside of the pot in mesh plastic, as I imagine most of, if not all the cat litter would fall through eventually?

Sad thing is I can't find any local shops keeping coco peat...

Hi Mike, the cat litter is calcined clay and though I've never used any kind of cat litter I do use calcined clay in the form of Turface. Just note that not all kitty litter is created equal and some can not be used. It depends on how high the clay is fired and I think turface is around 1200F. It's very hard and does not break down. Oil-dry is another calcined clay that I have heard works good amd most auto supply houses carry it. Turface you can get at farming, irrigation, or landscaping stores. It's used mostly to dry wet zones and in sports, the pitchers mounds are built from turface, among other uses.

If you must use cat litter and you don't know if it is proven to work well you can test the product by recreating the effects of over-wintering. Soak some in water and then freeze it in your freezer. Take it out and let it thaw and then freeze it again. Do this a few times and if it softens or turns to mush it will do the same in your pots.

Deco-bark is not decomposed bark. It's fresh bark taken from the lumber mills and paper industry. I get decomposed bark from dead pines in the forest. A standing snag will have tons of bark around the base. You can crush big chunks of it with your bare hands.

The mesh is called hardware cloth and you can get it at most farming supply store or Ace Hardware. There is a plastic type that I buy at hobby craft stores. The brass kind I found at an irrigation pump supplier, $$$$!

I hope that helps shed some light. As far as percentages goes, it varies from tree to tree and I'm still fretting it out. Each tree is a study in itself and pines in Oregon will want different soil mixes than pines in Norway. This is where your local clubs and growers can provide the best advice per tree.   Best of luck to you and your trees,  Rick

Muchas gracias for the tips, Rick! The cat litter I have in mind is suitable for bonsai as I've read other people using it with great success, so that's no-brainer. I read somewhere that Turface is a bad medium, i.e because it creates a thready root system and it's deadly hydrophobic property when dry. Actually here's a link to the site at which this was said. How credible it is I can't say, but I'm taking everything into consideration. As you use Turface yourself, what's your opinions on the negatives that he lists?

Okay, so deco-bark is out of the equation. I'll see if I can find a source of decomposed bark, if not your idea is brilliant as there's basically trees everywhere I look.

Okay. I can only find one type of mesh (with my limited search words as I have no idea how to translate hardware cloth into Norwegian), and that has too big holes for my purposes. As posted earlier though I have a good solution in store.

That does indeed help, Rick. Unfortunately there's no local clubs or growers anywhere near here, the closest I can think of is at least 8 hours away... I've tried finding Norwegian bonsai sites, but they all died in 2008/2009 it seems, so not to much help, hence the massive amount of questions put upon you, poor users of international bonsai forums.   

Best regards
Mike

This is speculation on my part, but it seems that using 100% Turface for the planting medium can result in bad root development, but amending it with other ingredients relieves that problem. I have a couple trident maples potted in a combination of Turface, diatomaceous earth, grit, and a small amount of pine bark fines. The root systems were robust when I went to repot it this year. But I did change their soil makeup this year to Akadama, pumice, lava in a ratio of 2/1/1.

To answer your question regarding Leca Safe grain size. I dont see it as a problem as the majority of the pellets are 3-4mm in size. It does not contain any fine dusts or anything. Some other more experienced people at my local bonsai club also uses it.
Another good thing about it is that it is mainly used to avoid people falling on icy walkways during the winter instead of using salt. This means that it is sold very cheap around march/april as the stores just want to get rid of it. I bought alot of it for just 15 DKR (2.5$) per 10 liters last april.


Regards,
Henrik

You might look into screen door screen, it comes in plastic woven (no good), plastic with the filaments stuck together (good stuff) and more expensive metal screening.
I have been using the good plastic screening for more than 25 years as hole covering in my ShoHin pots.

Okay, thanks for the input Kennedy.

Ah, that's very cheap! Doubt I'll find it that cheap here though, but cheaper than other alternatives - surely!

arihato, I would like to find that, but again I cannot find the proper words to find that product locally... We don't have/use door screens here in Norway as far as I'm aware, so that might be why though. Hopefully I've solved the problem with a good tip from Henrik.