THE USE OF HEATING MATS.

Here we are again at the start of another gardening year,my seeds should arrive in the mail any time now and then i will be all set to go.I use heating mats to germinate my seeds so i would like to share with you how i use them.Some gardeners like to put their seed trays directly on top of the heating pad.I used to do that,but not any more, as i used to have problems with them overheating and getting too warm.Most heating pads heat the soil to 10 t0 15 degrees above room temperature.What this means is,if your room temperature is 50 degrees they will heat the soil temperature to between 60 and 65 degrees.But,as there is no temperature thermostat on them they will not turn off.So if your room temperature goes up to 70 degrees they will heat the soil to between 80 and 85 degrees which is too hot for most seeds and you will not get good germination.To get good results from heating mats you do have to have a soil heating censor,when set, it will turn the power off to the heating mat when the soil reaches the temperature that you want it.You can set the censor to come on at 68 degrees and go off at 72 degrees,which is good for most seed germination.
I use my heating pads in a different way,i have a large germination box made of OSB and pieces of 6x1 boards.The OSB is 2 feet by 8 feet which i use for the bottom of the box,the 6x1 boards i use for the sides of the box.I have the box on top of a work bench i have in my shed.I then put a piece of plastic inside the box on top of the OSB,this keeps the OSB dry.Then i put 2 inches of damp play sand inside the box, making it level.On top of this i lay my heating pads,they are 48 inches long and 20 inches wide,i have two of them,one in one half of the box and one in the other.I cut a half inch slot in the side at each end of the box so the cable on the mats can fit in them.When the mats are inside i cover them again with another 2 inches of damp play sand leveling it off.After that i put another piece of plastic on top of that,this will stop the sand going dry and will keep the heat uniformed.The box now is only 2 inches deep,just enough to fit the seed tray in.I have a double heat control censor so i can run both mats off it.I can run one mat at 60 degrees and one mat at 70 if i want.I place the censors under the top layer of plastic,one in one half of the box and one in the other.The censors i use are used in reptile tanks and there is no fluctuation in temperature,they do not turn the power to the mat on and off,they just reduce the power going to them as needed.This is a good set up to use,i started 130 chrysanthemum cutting this year and i never lost any of them.In fact they are in the picture underneath this posting.You may wonder about the cost of this,i don't look at it as a cost,i look at it as an investment.The whole thing was around $300,it will last at least 5 years,$60 a year is not bad considering the amount of plants i grow.