Tool or Gardening Product
Heating mats provide a little bottom heat underneath a planting flat. The extra warmth will help get seedlings off to a much faster start even in cool conditions. These mats are also great for providing a little warmth for cuttings that you are rooting.
Clever Gardening Technique
It usually just takes a little extra heat to protect a semi-tender plant such as a dwarf citrus tree on a cold night. Hang a mechanic's light with a 100 watt bulb beneath the canopy and then cover the plant with a blanket or tarp that drapes all the way to the ground. The light will provide several degrees of warmth. Make sure not to allow it to touch branches or the trunk as the bulb can get very hot.