I'm considering using wood chips or mulch instead of perlite for my container vegetable garden. I've heard some concerns about nitrogen levels when using wood chips—how significant is this issue? Perlite seems costly at $6 for 8 quarts, while I can get mulch for $5 for 30 quarts. My current soil mixture consists of equal parts peat moss, leaf compost, and mulch. Any insights would be greatly appreciated!
3 Answers
Using wood chips as a big part of your mix isn't the best idea. They take a long time to decompose and can tie up nitrogen in the soil while they’re breaking down. If you're adding a third of your mix as wood chips, you might not have enough nitrogen available for your plants for quite some time. You might want to consider using vermiculite instead; I’ve found it to be cheaper and a good substitute for perlite.
I suggest checking the size of your mulch. If it's coarse mulch, using it as a bottom layer can work, but just mixing it in won’t give you the same benefits as perlite or vermiculite. In my area, we have options like 'evergreen topsoil' which is basically wood fines, and it can really help with drainage. Just keep an eye on fertilization since wood can pull nitrogen from the soil.
You might want to try hemp mulch as a substitute! It's lightweight like grains of rice and gets worked into the soil nicely, helping to keep things fluffy. I layer it in after the growing season and keep adding it each time I plant. Just be ready to mix it back into the soil as the seasons change!