I'm planning to save some money by creating my own potting soil. I've got some Miracle-Gro potting mix and I'm thinking of blending it with coco coir, perlite, and Timberline Farms brand manure and compost. However, I came across some advice saying not to mix manure and compost because it could lead to 'hot composting' and make the soil unsuitable for plants. Has anyone dealt with this? I'm trying to grow cucumbers, tomatoes, romaine, and jalapeños in zone 7b.
2 Answers
I’d steer clear of adding uncomposted manure to your mix. Fresh manure can tie up nutrients and may carry pathogens before it's fully decomposed. Instead, I’d suggest using a good mix like 2 parts coco coir, 1 part perlite or vermiculite, and 1 part properly composted material for a balanced blend. It works well for all kinds of plants, including seedlings and houseplants!
I did a quick search and found that Timberline manure is actually composted. Would that work for you?
I had a bad experience with Miracle-Gro potting mix; it got infested with fungus gnats. Just a heads-up!
Oh no, I'm in too deep with it now! Just hoping I don’t end up with them.

Exactly! It's best to be safe with the composting. Plus, that mix sounds really solid.