No luck with my peppers

bower · March 17, 2014

I love the heat mat for starting seeds, but there is a problem with ziplock bags in that situation, even with soil instead of wet filter paper. There is limited air in the zip, and if there is any respiration by sprouting seeds in the heat, they're at risk of suffocation. Heat levels build up much quicker inside a bag too.

I do like to cover my seed trays with raised domes, to keep the moisture level high without totally excluding air exchange - even then I have to fuss over them several times a day, knocking down the condensation and raising the lid to refresh the air. I take the seedlings off the heat as soon as they have sprouted. Yep, I cooked a few by leaving them on the pad too long once, learned my lesson. My heat pad doesn't have a thermostat either, and it seems to have a few 'hot spots'. This year I've put an extra 1020 tray between the pad and the cells or flats where seeds are planted to keep them up off the heat a bit.

My room temperature is about the same as yours, but if the soil seems very warm in the evening I will unplug it and let it cool overnight. This also simulates the normal variation of temperature day/night and it may actually be producing a faster germination than steady heat, afaict.

If you want to get your peppers started quickly, soak the seeds overnight in water, then plant and very lightly cover with soil or potting mix whatever, spritz the surface until drenched and then put them on the heat mat under the dome, moisten by spritzing once or twice a day as needed, they should be up in five days if the seeds are not too old or the peppers especially stubborn ones.

March 17, 2014	#11
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,793	I love the heat mat for starting seeds, but there is a problem with ziplock bags in that situation, even with soil instead of wet filter paper. There is limited air in the zip, and if there is any respiration by sprouting seeds in the heat, they're at risk of suffocation. Heat levels build up much quicker inside a bag too. I do like to cover my seed trays with raised domes, to keep the moisture level high without totally excluding air exchange - even then I have to fuss over them several times a day, knocking down the condensation and raising the lid to refresh the air. I take the seedlings off the heat as soon as they have sprouted. Yep, I cooked a few by leaving them on the pad too long once, learned my lesson. My heat pad doesn't have a thermostat either, and it seems to have a few 'hot spots'. This year I've put an extra 1020 tray between the pad and the cells or flats where seeds are planted to keep them up off the heat a bit. My room temperature is about the same as yours, but if the soil seems very warm in the evening I will unplug it and let it cool overnight. This also simulates the normal variation of temperature day/night and it may actually be producing a faster germination than steady heat, afaict. If you want to get your peppers started quickly, soak the seeds overnight in water, then plant and very lightly cover with soil or potting mix whatever, spritz the surface until drenched and then put them on the heat mat under the dome, moisten by spritzing once or twice a day as needed, they should be up in five days if the seeds are not too old or the peppers especially stubborn ones.