If you are ready to root cuttings of overgrown houseplants or start seeds for the spring garden, you need this sweet heat. Soil conditions kept just warmer than average room temperature will be fine to keep most roots happy and growing. Look for heating cables to warm a flat of soil or a mat to lie underneath it. Both will be labeled for greenhouse use and will have simple technologies to regulate heat. Better root systems develop when soils are consistently warm and though we should always water seedlings and clones with tepid water, we don’t always. Bottom heat helps to ameliorate that situation and keep growth proceeding apace. Keep reading for more about rooting plants with bottom heat.