Propagation: GreeneLady picture (Question about heat mats.)
In reply to: Question about heat mats.
I actually prefer soil cables instead of the heat mat because they are so much cheaper than a heat mat. I built a frame out of wood with some window screening stretched and stapled inside the frame. I then spread a thin layer of contractor grade (it's very course) sand on top of the screening, loop the cables on top of the first layer of sand, and then I put another layer of sand on top of the cables. The frame, sand, and cables sits atop of two sawhorses. I then sit my plantings in their flats or pots on top of the sand. This way water can drain away from the seedlings and I don't have to worry about them becoming waterlogged or getting over watered.
Some seeds like heirloom tomatoes must have bottom heat to prevent stretching spindly pants. However, some plants/seedlings like lettuce don't do as well with bottom source heat. It depends on what you are growning. I suggest doing a google search or here on DG to see if the the seeds you are trying to grow require bottom heat.
But yes, bottom heat works wonders on some plants.