Soil for trees growing/ thickening

[spunog]

At what stage do you need to start using a proper soil? I have several trees in very large buckets with the hope of them thickening ASAP. Should I be using bonsai mix at this stage or can I use any old soil for now ?

 

[Wires_Guy_wires]

I prefer working the roots and transitioning to bonsai soil first. The bigger the tree gets, the bigger the taproot and other unwanted structures will be. Once you have those fixed, they can grow freely with only minor adjustments needed.

You can always postpone that kind of work, it wouldn't harm the trees. But there is a possibility that, down the road, you'll be spending a lot of time working the roots.

 

[Tieball]

My experience: I don’t have any buckets. I do use old cleaned bonsai soil in the ground when I plant trees for thickening growth. I like the ground planting as nature, for my soil environment, does a great job of drainage and winter protection. The bonsai soil has helped significant root and tree growth...much greater than trees just in the ground with natural soil. My native soil is very sandy and free draining. The bonsai soil actually helps retain some moisture for me.

I do have some trees in wooden boxes though and always use...well, a lower end bonsai-type substrate and get strong growth results.

I have one tree in native soil only. Growth seems to be limited. Drainage is not great. It tends to get saturated with water to much. And...it’s extremely heavy to move around. The bonsai type soil would be much lighter...and healthier in my view.

 

[0soyoung]

At what stage do you need to start using a proper soil? I have several trees in very large buckets with the hope of them thickening ASAP. Should I be using bonsai mix at this stage or can I use any old soil for now ?

Bonsai substrates are the best, IMHO, but they are comparatively expensive and the tree roots must be secured. The also require close attention to watering and fertilization, which may or may not be a problem. Likewise, substrates are expensive compared to some satisfactory alternatives.

The problem with 'any old soil' is that it likely will have low air filled porosity which will cause slow growth. In my area of the U.S. tree bark (usually from Douglas fir) is readily available and inexpensive. It is used to dress garden beds and comes in small, medium, and large sizes. I mix medium bark with no more than an equal part (by volume) of potting soil. My only rationale for adding potting soil is that it makes the mix sticky enough that the tree will quickly not need any guying/tying to the pot. If you have bark available in Ireland, this mix is good for 3 to 5 years (after that, the bark decomposes and the air filled porosity declines rapidly). Add some balanced fertilizer once or twice in the first 2 years; none should be necessary after that.

In my experience, growth will be slower the 'stickier' the organic soil is (drag you finger across the surface and it sticks to your finger = basically clay content). Roots tend to become fewest in number, thickest at the trunk, and longest. Bonsai substrates tend to produce the highest numbers of roots which tend to be short and thin. Bark comes close to this for a fraction of the cost, but you will find roots insinuated into the bark chunks, which I find annoying, but really isn't a big deal.

 

[Leo in N E Illinois]

Roots with bark chips stuck to the root, is a sign the tree or the tree's mycorrhiza like that brand of bark.

I go to a bonsai media early in the grow out phase

 

[Cosmos]

At a conference earlier this fall, David Easterbrook told the attendees that to grow out a young tree in a pot, the optimal set-up is a large, rather shallow container with very coarse substrate (something like 1/4" or 0.5 cm). I can’t recall his exact words, but he suggested that the goal was to create as much fine roots and root subdivision as possible, as well as allow for quick colonization of the whole container. And he said that with soil like that you should hammer the tree with as much fertilizer as it can take.

 

[Bananaman]

And he said that with soil like that you should hammer the tree with as much fertilizer as it can take.

Do we just heap a two inch layer on the soil surface? Would that be the way to do it. If it can’t take no more do I get a text or something?

 

[Cosmos]

Do we just heap a two inch layer on the soil surface? Would that be the way to do it. If it can’t take no more do I get a text or something?

If you’re not putting at least an inch of fertilizer per inch of soil, you ain’t trying hard enough.

And if you kill your tree, did you know you can send a letter to Big Bonsai Inc. and they send you another one for free?

 

[Bananaman]

If you’re not putting at least an inch of fertilizer per inch of soil, you ain’t trying hard enough.

And if you kill your tree, did you know you can send a letter to Big Bonsai Inc. and they send you another one for free?

Saweeet!!

 

[spunog]

Thanks for the input , I’ll pop my trees into a decent substrate in the spring ?

 

[cornfed]

Resurrecting this thread instead of posting a new one.

I have some year-old trees that I'm potting up from 1-gallon pots to 5-gallons for thickening & root development.

I was planning on doing Sifted Pine Bark & Grit for a cheap substrate. But I like to test my soils using a method I learned from reading a paper by Heltsley. I made a sample mix and tested it, and it came back at 38% Saturated Porosity, but only 16% Field Capacity. The acceptable ranges (according to Heltsley, but I have no idea where he got them) are SP 25-45% and FC 18-28%. I had filtered all the fines out of the Pine Bark, and hence lost most of the field capacity. If I used this mix, I would be watering all day.



So I made a second mix using materials I have on hand (from my other tests). This time it was about 60% Sifted Pine Bark & Grit, with the remaining balance being Turface & DE for water retention. This tested at 36% saturated porosity and 24% field capacity, right in the money. All sifted to 2-5mm size.

But, and this is my question, should I worry about having all the substrate sifted to the 2-5mm size at this stage, or should I just go Unsifted Pine Bark and/or Spagham Peat Fines and add grit until the I get SP & FC in the right range? Because if I didn't have to worry about size, I could get my FC out from the fines of the Pine Bark or Sphagnum and I would not need any Turface or DE for moisture retention.

I hear the fines negatively impact drainage, which is why I sift them out. BUT, this isn't a bonsai pot either, and they had been growing their whole first year in 80% composted pine bark, fines and all.

Thank you!

 

[Agriff]

I was planning on doing Sifted Pine Bark & Grit for a cheap substrate. But I like to test my soils using a method I learned from reading a paper by Heltsley.

But, and this is my question, should I worry about having all the substrate sifted to the 2-5mm size at this stage, or should I just go Unsifted Pine Bark and/or Spagham Peat Fines and add grit until the I get SP & FC in the right range? Because if I didn't have to worry about size, I could get my FC out from the fines of the Pine Bark or Sphagnum and I would not need any Turface or DE for moisture retention.

I hear the fines negatively impact drainage, which is why I sift them out. BUT, this isn't a bonsai pot either, and they had been growing their whole first year in 80% composted pine bark, fines and all.

Thank you!

Bumping this because I'm also wondering about growing out of bonsai pots. That paper was super helpful!

 

[cornfed]

I found an even better paper here on BNut by markyscott after I wrote the above, if you're interested.

Introductory Soil Physics

Here is the second resource developed from the thread "Introductory Soil Physics". It is a document explaining how the important physical properties in soil and substrates combine to control the amount of air and water in the pore space of soils...

www.bonsainut.com

 

[Tums]

I found an even better paper here on BNut by markyscott after I wrote the above, if you're interested.

Introductory Soil Physics

Here is the second resource developed from the thread "Introductory Soil Physics". It is a document explaining how the important physical properties in soil and substrates combine to control the amount of air and water in the pore space of soils...

www.bonsainut.com

So practically speaking, if your AFP continues to be high after you add the fines to your mix, then they're not really negatively impacting your drainage, right? And simplifying the mix sounds appealing to me as long as the numbers work out.

 

[cornfed]

In theory the fines will make their way to the bottom of the pot over time. That'll create a strata of poor drainage at the bottom and effectively raise the water table inside the pot. In my particular circumstance, with ten-inch tall air-pruning pots and the extra drainage holes that come with it, I didn't deem that to be a problem.

Ultimately I ended up not using any fines in my substrate after the first five. The goal for my first trees is to grow as fast as possible, so I decided a higher Air-filled space with more frequent watering and fertilizing would be my best move.

Remember, what you use is going to be dependent on your goals, watering habits and climate. There is no one perfect soil, that's why we have the Soil Wars... because many people have a strong opinion based on what works for them. The most knowledgeable guy in my local club has used 50:50 #1 Chicken Grit & Unsifted Pine Bark for 60 years. I might fall back on that after doing my own experiments for a couple years. It certainly is cheaper!