gtarman Posted December 13, 2013 Hey all. So I've been brainstorming ways of getting slow-growing and rot-prone seedlings to maturity with higher rates of survival. I've had success using gravel mulch for this purpose, and have found that it retains moisture in the root zone more consistently but also keeps that moisture away from the seedling itself which is working quite well for plant health and mortality overall. The only problem is with some seedlings that are really small, even my 2mm gravel is too large. The only 1mm gravel I've been able to find is this stuff, which is black silica gravel. I don't really know much about silica as a material, so I thought I'd ask here if anyone can foresee it causing the plants any problems, or if it's more or less inert and okay to use? Cheers Gman Share this post Link to post Share on other sites
tripsis Posted December 13, 2013 It would be fine. Silica is an essential plant nutrient. Diatomite, my favourite media for cacti, is essentially just silica. Why not just use coarse sand? You can sieve it yourself to control particle size. 2 Share this post Link to post Share on other sites
gtarman Posted December 13, 2013 I do sieve my own sand already for use in potting mixes, but I don't have the right sieve sizes to get it down to uniform grades. Plus I find that you almost always still end up with some fine particles, which isn't really a problem when you're mixing it with soil, but I wouldn't want to use it as mulch. I probably could use it, but I'm a bit pedantic when it comes to these sorts of things. My intuition tells me it won't work as well is probably the best way to put it lol Share this post Link to post Share on other sites
tripsis Posted December 13, 2013 Use two sieves. One very fine one, to wash away very fine material, and another one with mesh the diameter of particles you are after. 1 mm is probably too small to provide support. 2 mm should work. Share this post Link to post Share on other sites
gtarman Posted December 13, 2013 (edited) lol I said no dammit! EDIT: actually I didn't technically say no haha. But nah I already have 2mm gravel and it's too coarse for some applications. 1mm is definitely what I'm after. And using two sieves like I said isn't an option - not if I want something calibrated and uniform, which I do. The one sieve I do have is a rugged prospecting sieve that has exact decimal millimeter gradings. A lot of folk use the standard kitchen sieves and what have you, but like I say, I'm pedantic. Cheers for the lowdown on silica though Edited December 13, 2013 by gtarman Share this post Link to post Share on other sites
