Heat For Seeds
The Germination Secret

The other thing that was missing in that icy puddle was sufficient warmth

to tell the seed that it had at least a moderate chance of growing if it started to absorb the apparently ‘available’ water. Seeds tend not to be suicidal and will not come out of their comfortable dormant state until they feel that the conditions for successful growth and continuation of their species are present.


We All Like To Be Warm!
That is the second hurdle that we must overcome. Putting some nice fresh seed into a perfect germinating soil mix that has been properly moistened will produce very few seedlings unless the optimum temperature for germination is present.


Heat For Seeds From Where?
Now seed growing starts to get even trickier. Most of would tend to set up our seed growing operation in the basement or some other out of the way location where the presence of soil and water will not upset the tidier members of our households. These are probably not the warmest spots in our homes. Now we need to supply some supplemental heat. The good part of this is that the seeds are in the soil and not in the air so we only need to warm up the soil.

A Welcome Mat!
There are warm spots in most houses, such as the tops of radiators or the top of the refrigerator but the better solution is a heat mat that is designed for the purpose. It’s water proof, got a thermostat, (to avoid actually cooking your seeds,) and almost every seed catalogue has them at a reasonable price. Our tomato seeds would like a soil temperature around 75 F / 24 C and are quite happy if the air is several degrees cooler.


More Heat Please!
Once you have grown your first batch of seedlings, you will discover that the little heat mat is, just that, little. To create a larger germination space I have a table with sides that will hold a quantity of the soil less mix or sand, (much heavier.) In that material I bury a heating cable. These cables can be purchased with a built in thermostat to provide a large warm area. Now you can germinate all of the seeds, that were in the catalogue, that you just couldn’t do without. The material in which the cable is buried must be kept moist or the heating cable will overheat and burn out. The water in the mixture helps to spread the heat for the seeds evenly through the entire table.


The supply of bottom heat is one of the real secrets to success in seed starting. The water and light are obvious but without sufficient heat for seeds they will just lay there and slowly rot.

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