Our Ferry-Morse Heat Mat is the secret to successful seed germination! The mat provides bottom heat which signals the seeds to begin germinating. Large enough for a standard starter tray” this 10″ x 20″ mat will work well with any Jiffy seed starting kit. Easy to use; simply plug it in and the mat will maintain the optimum temperature range for most seeds to germinate. After seeds have germinated and are sprouting up” remove seedling tray from heat mat and place seedlings in a sunny window or under a grow light.