In the Garden

Ask the master gardeners

Q: How do you make your own potting soil?

A: First, ask yourself what type of plants you will grow because the soil mixture will vary. Then estimate how much soil you need. If you are just repotting a few houseplants, you may want to buy a commercial potting mix. If you are growing vegetables in containers, however, it may be more economical to make your own soil.

For vegetables in containers, use:
5 parts compost
1 part sharp (builders) sand
1 part vermiculite or perlite
1 part milled sphagnum moss

For ornamentals (houseplants), use:
2 parts commercial garden/vegetable mix
2 parts compost
1 part sharp (builders) sand
1 part vermiculite or perlite

Buy the ingredients at your local garden center.

To grow healthy plants, you need a light soil that supports the plant and allows air and water to move through it. Never use soil from your yard. That soil is too heavy and will become compacted, preventing air from reaching the roots. If your containers get a lot of rain, it is better to use perlite than vermiculite.

One cubic yard equals 27 cubic feet or 22 bushels. Because a 15 to 20 percent shrinkage occurs in mixing, for 1 full yard of mix use an additional 3 to 5 cubic feet. To compare size, most prepared commercial soil mixes come in bags of 1, 2 or 3 cubic yards.
— Kim Farro, master gardener, Cornell Cooperative Extension of Rockland

 Print |  Email