Seed Starting Secrets of a Greenhouse Professional

This article was written by The Natural Gardening Company for Mother Earth News We began producing certified organic vegetable transplants 23 years ago at The Natural Gardening Company with very little experience under our belt. Since the early days we have produced well over a half million seedlings, learning by trial and error. I have no doubt there is more to learn, but this blog will provide you with a summary of our seed starting technique. Where we learned from mistakes, you can have the benefit of our two+ decades of experience.

Our Soil Mix

We’ve fiddled around with our seed starting mix over the years. In the beginning we used a classic formulation: 1/3 peat moss, 1/3 perlite and 1/3 organic material (usually compost or aged steer manure). These are readily available materials and they work well, with one shortcoming. When seeds using this formula are planted in plug trays and placed in a sunny location, direct sunlight and high heat can cause mold to grow on the surface. This mold eventually becomes a crust. This crusty layer impedes the penetration of water from above and suppresses the upward development of the seed from below. The crust does not completely inhibit the development of seeds in the tray, but it greatly reduces the rate of germination...