Add This Strong, Robust, Flexible Cable To Soil In A Raised Bed Outdoors, In A Greenhouse Or A Large Cold Frame & It Will Heat The Soil Or Sharp Sand For Optimum Root Development For All Your Plants.the Ideal Way To Propagate Seeds & Cuttings For Strong, Healthy Young Plants Which Will Flower More Freely & Produce Fruit & Vegetables Earlier In The Season.lay The Cable In A Snake-like Run Of Rows Set 7.5-10cm (3-4 In) Apart On 5cm (2in) Of Horticultural Sharp S&. This Layout Will Allow Soil Temperature To Rise By 11-13° C (52-55°f) With A Greenhouse Temperature Of 7°c (45°f).you Can Achieve Higher Temperatures By Laying Rows Closer Together. Just Add A Thermostat To The Soil To Ensure The Correct Temperature Range For Your Growing Seedlings & Young Plants.area Cover: 1.75 Square Metres (16 Square Feet)