Citrus Growers Forum

stressbaby · Posted: Sun 27 Jan, 2008 10:25 pm

My next experiment will be to substitute Turface for the perlite in my bark and CHC mixes. Potential advantages include good CEC, holds its weight in water (40-50% internal porosity), heavy enought to help hold down root systems and pots, won't (or shouldn't) float to the top of the container, and maybe aesthetics.

Anybody tried it?

Makrut · Joined: 23 Dec 2007 Posts: 10 Location: Bishop, CA

I'm using equal parts CHC (1/4" to 1/2"), Coir, diatomaceous earth, and Kellogg Topper topsoil (composted forest humus and manure) for container citrus and figs. I've only just started using this mix, but it seems maintain aeration, drain well, and hold moisture well.

Diatomaceous earth (DE) is similar to Turface, and I like it much better than perlite because it doesn't float in the soil and isn't so crumbly. And its brownish tan instead of white.

I put 6 oz of DE (Oil-Dri brand) in a plastic cup then weighed it before and after adding water (and pouring off the extra water). It crackles as it absorbs the water, and the cup of it weighed 10.8 oz after I had poured off the extra water and let it site overnight. So it looks like it holds at least 50% of its weight in water.

Andrew

fftulip · Joined: 29 Nov 2007 Posts: 19 Location: Lake Hughes, CA

For those of you having trouble finding a local supplier of coconut husk chips, try a hydroponics supply shop. Here in California we seem to have a hydroponics store in every town (wonder what people are growing Twisted Evil

?). I was able to get 40 liter bags (about 1.5 cu ft) of CHC for about $12 each at my local Palmdale Discount Hydroponics shop. Note it may be called something like "coco croutons" or "piece coir" (the stuff I bought, a mix of 1/4 inch to 1 inch coco chips, averaging about 1/2 inch).

I couldn't find CHC at any local garden centers. Ace hardware stores do apparently carry it under the "Mulch Block" name, but the nearest one to me is two hours away so I haven't checked that product out yet.

The hydroponics store also carries an interesting growing medium derived from volcanic rocks called "Higromite". Anyone tried this stuff? It seems to have a number of advantages over perlite in that it probably doesn't migrate as much to the surface, and looks to be more durable. P*t growers and orchid growers have reported good results with Higromite. Here are a couple of links on it:
http://www.higromite.com/
http://www.chebucto.ns.ca/Recreation/OrchidSNS/news/05/05octnews.pdf
(review of Higromite on page 7).