Sift pine soil conditioner?

[Glorfindel]

I will be putting a dawn redwood in a growbox. Do I need to sift out any of the really small soil conditioner particles out? Or should I be leaving them in there? Will be mixing with pumice. Also have some lava and perlite on hand.

 

[sorce]

Depends on if it's worth it. Doesn't make sense to sift something that will just continue to break down and leave fine particles.

How big are the drain holes?

Sorce

 

[HENDO]

I was also wondering about sifting soil conditioner. Do you try to match the size of the inorganics?

I need to make some development mix for tropicals and would like the fines out somewhat, for aeration. Will probably just leave the plants in this mix for a year so not super concerned about it breaking down.

 

[Bonsai Nut]

I sift everything... though I agree with Sorce's comment that the pine is eventually going to break down. However I try not to use more than 25% organic in any mix (in general), and use less organic in pots than in growing containers like Anderson flats or large pond baskets. So even though the organics will break down, it will take some time, and in the case of sifted pine bark it will be years. So in my opinion it is best to sift out the fine particles so that your soil freely drains as long as possible.

Take the fines and use them for cuttings... or for soil amendment in your garden

 

[HENDO]

I sift everything... though I agree with Sorce's comment that the pine is eventually going to break down. However I try not to use more than 25% organic in any mix (in general), and use less organic in pots than in growing containers like Anderson flats or large pond baskets. So even though the organics will break down, it will take some time, and in the case of sifted pine bark it will be years. So in my opinion it is best to sift out the fine particles so that your soil freely drains as long as possible.

Take the fines and use them for cuttings... or for soil amendment in your garden

I was thinking a 40:40:20 - Pumice:Lava:Soil Conditioner.

Sounds simple enough. So from the sounds of it, the fines can just be sifted out, toss any huge chunks, and then the sifted soil conditioner is good to mix in?

 

[Mellow Mullet]

I used to not sift it, but at repotting I saw how much mud the fines left in the bottom of the pot. So I now sift it. I have some simple 18 inch square wooden frames that I made the first is 1/2 inch, the second is 1/4 inch and the bottom is 1/8 inch. Everything that goes completely through just goes on the ground (helps the lawn, lol), the 1/8 to 1/4 is used for bonsai soil, the 1/2 inch and up is used as a top dressing for freshly repotted trees. I used to use sphagnum moss for a top dressing, but in my neck of the woods it turn into a hot mess in a few weeks (algae and black goo). If you are repotting every couple of years, the bark will not be broken down. I have repotted some that had gone three to four years and the bark was still intact.

John

 

[cornfed]

I'm new too. But I did some Heltsey style tests on pine bark and found that most of the moisture retention is in the fines. Another study I've seen proves that most of the CEC is in the fines too.

Moisture Retention and CEC are the main reasons to use Pine Bark, as I understand it. But the fines can impact drainage... So there is the dilemma.

I ended up using sifted 2-5mm bark as 1/6th of my mix.

When I get home to my notebook I'll share the results.

Experienced people, check my theory. I'm new too.

 

[cornfed]

The results from my experiment. And a link to the study on Pine Bark CEC & Particle Size.