Christmas is coming and people are getting stressed by questions such as ‘what present can we get for (fill in the name yourself)?’ If they have a tunnel or glasshouse, how about something to increase their enjoyment of it? They could use a soil warming cable in so many different ways that it is almost certain to expand the range of plants they can grow and/or extend their growing season.
The theory is simple. The cable is buried below the surface of a bed of ‘sharp sand’. When warmed by electricity it warms the surrounding sand, in turn heating the soil or peat moss in pots and seedtrays sitting on the sand. S
oil temperature affects plant growth more than air temperature. Seeds germinate faster, cuttings root sooner and growth continues when the air temperature drops a bit too low for normal growth. Insulating fleece or bubble-wrap over the plants will protect them from a few more degrees of frost due to the rising heat. Adding a thermostat will save electricity when the sun warms the soil naturally; see soil warming cables on the Polydome website. You can heat a whole bed or just a small propagation area, but if the latter it’s more convenient to have it on a raised bench or staging in which case you should place insulation underneath it.
Electricity and water are an unsafe mixture. Make sure you use a qualified electrician to lay on power to a glasshouse or tunnel, and follow the installation instructions carefully.
