Build your own propagator with these Bio Green soil warming cables or use as under soil heating in your greenhouse. Soil warming cables are mains operated, fully insulated, safe and easy to use (full instructions supplied). Soil Warming Cables are recommended for areas of 0.5 sq.m.(25W), 1.0 sq.m.(50W), 1.2 sq.m.(75W), 1.5 sq.m(100W)., and 4.0 sq.m.(320W), respectively. We recommend that you use the Bio Green Digital thermostat TR-E (JH1727) with these Soil Warming Cables for accurate temperature control and ease of connection. (Please note that the moulded plug on the heating cable must NOT be removed if attempting to wire these heating cables to any other thermostat)
A soil warming cable is the ideal way to propagate seeds and cuttings on a greenhouse bench. A simple frame can be constructed from wood to form the propagating area required, which is them lined with polythene. The cable is laid onto a 5cm of horticultural sharp sand and covered with a further 5cm of sand. Alternatively the cable can be laid out on to an insulating material like polystyrene sheet and covered over with tin foil then a layer of polythene and then some felt matting to hold moisture under the seedtrays.
The cable is normally laid in runs 8 cm to 10 cm apart. This layout will allow you to raise the soil temperature by 11-13 C, above the greenhouse ambient. Higher temperatures can be achieved by laying the cable runs as close together as 5cm. In this case a thermostat should be used to precisely control the soil temperature to avoid over heating.