Soil mix
To plant my balcony garden I want to mix last year's soil from containers with organic topsoil. Do I need to add vermiculite or perlite to make it lighter? I am planning to grow greens and flowers. I live in Montreal, Canada.
Submitted by tiaverde

Hi, Well it would be a lot easier if you just added new commercial grade potting mix instead of topsoil. Topsoil, even if it has a lot of organic matter in it, can become quite hard if it dries out at any time in a container. If this topsoil is all you have to work with I would definitely add vermiculite or perlite (you don't need both), sphagnum peat moss, and compost to the mix. Or, it would be easier and cost effective to just buy potting soil that's pre-mixed and ready to go.

Answered by doug.jimerson