Make Your Own Potting Soil

We are getting ready to start our spring crop seeds soon based on our hardiness zone in Wake Forest, NC. We are in the hardiness zone 7, which means that our typical last frost date is around April 11 – 20 each year, or April 16 on average. And according to my set out dates, germination and growing dates, we have calculated the seed start dates for all our produce, which means that parsley seeds should have been started on January 10, and onions seeds are due to be started on January 28.

I found a great seed starting soil mix recipe on the Organic Gardening website under the title Blend Your Own Seed-Starting Mix, I made several 10-gallon batches of this last year, and just made a 12-gallon batch yesterday.  I will show you how I made my 12-gallon batch.

The recipe is quite easy to follow, you just make sure that your volume measurements are equivalent for each product.

  • 4 parts screened compost
  • 2 parts sphagnum peat moss and/or coir
  • 1 part vermiculite
  • 1 part perlite

Just measure and mix the ingredients into a large container or a wheelbarrow like I do.

Here are the steps I used to screen my compost.

Harvest the mature compost from the bin

Harvesting Compost









Screen the compost into the wheelbarrow using hardware wire cloth.

Screen Compost









Shake the compost through the screen to keep large undecomposed organic material out.

Shake the compost









Add your peat moss, perlite, and vermiculite to the container or wheelbarrow.

Peat Moss



























Then blend the materials well with your shovel, and transfer to your holding containers for your seedling pots or trays.

Potting soil mixed