Some types of seeds require warmth for successful germination. Seedling heat mats raise the temperature of nursery flats or pots from 10 to 20 degrees above room temperature and produce heartier seedlings in less time. They can be reused many times and they are safe for indoor use as long as any accompanying safety warnings are heeded.
Step 1 – Purchase a seedling heat mat with a temperature control. You’ll want the temperature control to ensure consistent heat while your seeds are germinating. You can find them almost anywhere garden supplies are sold, as well as online here.
Step 2 – Plug the heat mat into a heavy-duty, grounded extension cord. Make sure the extension cord is plugged into a ground-fault circuit interrupter (GFCI) outlet for maximum safety.
Step 3 – Set the temperature control to between 75 and 80 degrees Fahrenheit. Allow 15 minutes for the pad to reach the desired temperature, then place nursery flats or pots on top of it. Do not alter the temperature over time, as seedlings will be most successful with a consistent level of heat.
Step 4 – Remove plants from the heat mat once they sprout and move them to a cooler, room-temperature location. Transplant them to larger pots or outdoors as they continue to grow. Always unplug the seedling heat mat when not in use.
If you can’t afford a seedling heat mat, check out these helpful DIY tips from Dave’s Garden to create your own seedling heating station.