Thanks in advance for the help! I'm trying to make some potting mix for an herb/annual veggie container garden without using perlite/vermiculite. I have read a lot on this forum about substituting leaf mold as a substitute in potting mix - like 1 part topsoil, 1 part compost, 1 part leaf mold. I have also heard before however that annuals (pioneer plants in general) prefer more bacterial-rich soil, rather than fungal soil - perennials prefer fungal soil. This makes sense from a succession perspective.
It seems people have success with using leaf mold in potting soil, so I guess I'm curious - why is this working? Are there other substitutes that would provide the aeration and drainage yet promote a more bacterial soil for these annual veggies? Any thoughts appreciated!
If your going for soil bacteria count I'd say consider inoculation. There are ones you can buy but who wants to buy? I like to take soil from various places like the woods, organic gardens, and wherever seems good. I mix that soil into my gardens by simply throwing it about before or during sheet mulching. I'd imagine it could be mixed in a potting mix also. Hope that helps, I don't do many plants in pots yet, I mostly just try to concentrate "energy" by putting whatever I find as far as biomass together.
Instead of truckage leaves to the curb, recycle them the manner nature will, by turning them into a useful soil builder. mold greatly improves the structure and water-holding capability of soil. It additionally creates the proper conditions for the community of useful organisms that dwell in your soil, and it's nice in the potting combine.
There's very no excuse to not create mold. It's free, easy-to-make, and promptly out there. If you do not have enough leaves in your own yard, trade raking duty along with your neighbors in exchange for theirs. Before you utilize leaves that have fallen on your neighbors' lawns, make certain to raise them if the grass has recently been sprayed with artificial chemicals.
If you're just looking to replace perlite/vermiculite you can get rice hulls at most agriculture supply spots. But I would think that using leaf mold, presumably free, would be a better option. Just because annuals prefer bacterially dominant soil doesn't mean that they don't like fungi as well. Also anything that you are growing for the fruit or flower bud (tomatoes, peppers, broccoli, cabbage, etc..) is going to like fungi because it's mycorhizal relationships that are most important in transporting P.
Potting mix that works best for herbs actually doesn't compare to soil except in the microbiome department.
A good potting mix will hold water but not be easily water logged, it will drain the excess water away fast.
It will have plenty of air spaces as the water is used by the roots.
1/3 sand, 1/3 leaf mold, 1/3 peat is a great starting mix, from there you can tweak it to optimize your plant results.