Yeah, shes my growing mentor. She grow 150 tomato plants in a 50/50 mix of promix and compost right now, but I think there is a better way for cannabis.
If she's growing in beds and/or holes in the ground, this definitely works. For indoor/pots though, extra perlite is definitely a requirement, 30-40% of the mix should be perlite in pots.
As for growing in the ground? The perlite needed is much more minimal, especially if your native top soil has lots of sand in clay in it. I buy a 3 cuft of Kellogg compost mix, dig a hole, mix the native dirt with the compost mix and now I have 5 cuft of soil for $8 and some digging. To that 5 cuft, I add 1 cuft perlite.
Promix comes with perlite, and if she's growing in the ground then she can get away with the amount of perlite in the pro-mix.
If she's got that many tomatoes, it's reasonable to infer that she makes her own compost by this point, yes? If the compost is homemade? 30% is definitely a great ratio. Store bought compost? Not so much, aside from a few rare exceptions. If she's got her own compost pile, its very easy to see why she's having so much success with the promix/compost mix.
Indoor/pot growers typically need to add extra drainage to store bought soils, to prevent stagnant water. In the ground, stagnant water will be a rare occurrence, if one at all.
Hi guys! I want to try growing organic and I figured I could do it with what I have laying around at home in my greenhouse. I plan on adding 4-4-4 Gaia Green fertilizer, granular K-Mag, granular boron and calcium powder (volatenite) as well.
Does that sound like a decent soil-mix / "supersoil", or am I missing anything?
Thanks!!
K-mag, as in Sul-po-mag/Langbeinite? Don't add that to your soil, way excessive for new plants. Langbeinite is great, but only if you know you have a plant that is that heavy of a feeder. I use the tiniest bit of it midway through flower/fruiting, and only if it looks like the plant will need it, or I know it's a heavy feeder.
4-4-4 Gaia Green is good stuff, if the Promix is new then no need to use 4-4-4 yet. Top dress with it in 4-6 weeks, and reapply as directed on the package. Old/used pro-mix will need to be re-amended. The promix and compost will have plenty for young plants. In fact, if your wife has homemade quality compost, and that's what you're using, you
What is the purpose of the granular boron or calcium powders? Your 4-4-4 mix already has plenty of Calcium inputs (gypsum and oyster flour), doubtful you'll need the calcium powders. Plants do need boron, however products like TM-7 or Big 6 are preferable for micro-nutrients if possible.
All of that said though? If your wife is making her own compost, and is doing so well with tomatoes, then she definitely knows her stuff. If this is the case, pick her brain and seek her input as often as you can. She sounds like she has a lot of experience, and if she's been making her own compost for a long enough time? That compost will do better than any product you can buy, even better if it's turned into EWC.
Regards.