Start Seeds with Soil Blocks
FINDING ANY TECHNIQUE that’s simpler, more effective, and less expensive than what’s been used before is satisfying. This is true for the production of transplants, and soil blocks meet these criteria. The Dutch have been developing this technique for more than 100 years, but the human history of growing plants in cubes of soil goes back 2,000 years or more. The story of how Aztec horticulturists of the chinampas of Xochimilco, Mexico, used cubes of rich mud to grow seedlings makes fascinating reading. A related technique is the old market gardener’s practice of using 4- to 5-inch (10- to 13-centimeter) cubes of partially decomposed inverted sod for growing melon and cucumber transplants.
HOW SOIL BLOCKS WORK
A soil block is pretty much what the name implies — a block made out of lightly compressed potting soil. It serves as both the container and the growing medium for a transplant seedling. The blocks are composed entirely of potting soil and have no walls as such. Because they’re pressed out by a form rather than filled into a form, air spaces provide the walls. Instead of the roots circling, as they do upon reaching the wall of a
