Soil Warming Cables
Soil warming cables are one of the most economical ways of creating a propagation bed. Firstly lay out your soil warming cable like a wiggly snake over your bench with the cable about 4-7 inches apart. Then cover with soil or better still building sand. You then have a constantly warm bench that you can place your seed trays directly on top – aiding germination or propagation.
You can also add rod thermostats to the setup for better control