Garden soil mix - Ask Extension
Greetings. I'm going to try square foot gardening for the first time in a 4x4 raised bed. I'm reading Mel Bartholomew's book and he recommends a mixtu...
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Garden soil mix #786673
Asked April 13, 2022, 8:30 AM EDT
Greetings. I'm going to try square foot gardening for the first time in a 4x4 raised bed. I'm reading Mel Bartholomew's book and he recommends a mixture of 1/3 garden compost, 1/3 peat moss, and 1/3 vermiculite. The garden store has raised bed mix that is compost, peat, and perlite. Is it better to use a mixture with vermiculite or perlite? What are the tradeoffs? Thank you.
Ramsey County Minnesota
Expert Response
Thank you for your patience with my delay in answering your question. Perlite is made out of minced volcanic rock and vermiculite is an aluminum silicate material. Both allow for aeration of the soil and moisture control. Perlite holds moisture for a short period of time allowing beds to dry out between waterings. Vermiculite holds moisture for longer periods of time and can lead to root rot in some plants if it is a high moisture year. Both support a good mixture for raised beds in a Minnesota climate.
