The added volume of pumice would make up for its extra water retention. I know that seems contradictory, but since the pumice holds more water than granite, and Turface holds more water than pumice, you need to DECREASE the most water-retentive ingredient & increase the ingredient with less water retention to come out at about the same water retention as the basic gritty mix.

AL

Al

Al

what do you recommend to use as a screen for the pine bark fines?

I've looked around a bit online and have only come up with expensive gold panning screens.

TIA.

Garrett.

Josh

thanks for the quick reply.

G.

Anyone else: so I need a 1/4" screen to eliminate particles over that size. Whatever falls through will be sifted through another screen of 1/8" size to eliminate anything smaller than that?

But -- how might the leftovers and used gritty mix affect the native soil if thrown on garden beds? Does it cause significant changes in the pH or minerals in the soil?

Al

Al

Nest season, changing to raised beds and will have plenty of leftovers to toss in. ;-)

JJ

Hi Al,

>>> The organic fraction will be consumed by soil life and gas-out' over time & the granite & Turface will become a part of the soil. About the only effect you'll notice id faster drainage and reduced water retention over time, if you toss a LOT of soil on your garden's/beds.

I would've assumed it increases water retention. Don't the smallest Turface fines also hold water internally? If so, it should be more than the granite fines would offset -- so much waste from Turface. I have fairly heavy clay-loam soil, so it probably would make little overall difference.

I think all that dust from the bark will be good for the beds in the long-term, but in the short-term will take up lots of space for the oxygen and may be a problem if all piled in one spot. It should also tie up some N in the breakdown process.

Here is what happened to mine:
I put about 1 cuft down into a small area, piled about 6" thick. It was my first batch of bark+Turface+Granite fines a few years back. The first year it repelled water quite a bit and killed the native Bermuda grass under it (I expected as much, grass needs sun). Then it got very moldy from sprinkler water and during winter. The 2nd year the mold didn't return after summer dried it out. By the third year, it looked almost identical from the top-surface view as prior years -- like nothing had changed in all that time. I went to remove a section (I was digging out for sprinkler repair) and lo-and-behold it was fixed solid in the soil. The surrounding Bermuda grass had sent many,many fine roots into it and were sucking the water dry as fast as the sprinklers filled it up. These weren't typical large bermuda roots/rhisomes normally in my soil, but very fine ones you see in young seedlings -- except they were very long and very healthy. Earthworms were already making their way into the stuff, also.

As for what I do with the leftovers, well, the screened out pine bark gets used as mulch under my pine and spruce trees. I suppose you could mulch anything with it though. My grit doesn't really have any waste other then dust, so nothing to say about that. For the small leftover turface, I toss it in a bucket for use as oil-sorb in the garage.

Joe

A well-made gritty mix, 100% screened Turface, 50/50 screened Turface & crushed granite, or any combination of screened Turface, granite and screened perlite are all excellent media for cuttings.

What I HAVE done in the past, is sow seeds on top of a very coarse medium (like I mentioned) & only cover them with Turface fines (1/8") and mist to keep the surface moist until the seeds germinate.

AL

Joel, or anybody,
Whenever I drill soft plastic, tough chads partially block the holes.
No prob if for drainage. Yes prob for screening.
Unreasonably laborious to remove chads.
Also, removal processes result in holes larger than chosen gauge.
To drill every hole twice, the first time smaller, is not a solution.
Yes, second drilling removes chads -- and it makes new ones.