Sunday, March 13, 2011
Using Soil Blocks for Growing Seedlings
A recent comment from Jeph at “Fresh is Best” has prompted me to share my experience so far with growing seedlings using soil blocks. As I explained to Jeph, I am no expert as this is only my second year of both growing my own seedlings and using soil blocks. However, my overall experience last year was so positive that I will continue to use soil blocks for most of my seedlings this year.
Previous to growing my own seedlings last year, my garden was planted with purchased transplants and direct seeding. I usually do a lot of research on new gardening methods that appeal to me before trying them. So, I had been reading and learning about seed starting and soil blocks for years before deciding to try it myself.
Once I decided to grow my seedlings from seed, I knew I wanted to invest in a 2-inch Soil Block Maker. I purchased mine last year from Johnny’s Selected Seeds.
The recommended soil block recipe is from Eliot Coleman’s book: The New Organic Grower and a copy was sent with the soil block maker I purchased last year and can be downloaded for the Johnny’s Selected Seeds website.
Last year I had problems sourcing out these ingredients during the winter months. However, most of my research told me that alternative soil mixes have also been used with good results as long as the soil mixture is fibrous enough to hold together through many waterings but allow air to pass through to provide oxygen to the roots and to permit drainage.
The recommend mix is composed of peat, lime, coarse sand or perlite, fertilizer, compost and soil. What I could easily find in January was organic seed starting mix made from approximately 80% peat moss, 19% perlite, and 1% lime. I also had some organic bagged compost on hand and some Plant Tone fertilizer by Epsoma. So I thought I would mix up a batch and give it a try: “I Played With the Soil Block Maker!” I passed the compost through a piece of hardware cloth into a tote to screen out any lumps before adding it to the mixture.
The test soil blocks retained moisture and held up well to being moved around and organized into different trays. So I proceeded with using this soil block mixture for my spring seedlings. I did fertilize with fish emulsion when the seedlings showed they need it, which was several weeks after germination, then every two weeks until planted in the garden. I had very good results and my seedlings were healthier and stronger than any transplants I had purchased before. When potting up or transplanting to the garden there is no transplant shock since you are not disturbing the roots. The transplants just continue to grow.
The fall seedlings were started in soil blocks made from Pro-Mix Potting & Seeding Mix (Made from Canadian sphagnum peat moss, limestone, perlite, vermiculite, and a wetting agent), screened compost, and a sprinkle of Plant Tone by Epsoma. This will be my second year growing from seed and I am using the Pro-Mix, screened compost, Plant Tone method again for my soil blocks.
I use a dishpan to mix up small batching of soil block mix as needed. I add Pro-Mix and screened compost to the dishpan at a ratio of approximately 3 scoops of Pro-Mix to 1 scoop of screened compost. I sprinkle in a couple of tablespoons of Plant Tone by Epsoma and add water. I mix the soil and water together then I let it sit for a few hours or even until the next day. This gives the mixture ample opportunity to soak up as much water as it can.
Johnny’s has a great video showing how to make the soilblocks: Click here to view.