I am starting some "new to me" annual seeds this year. I have experience with some annuals and many veggies and I usually separate them into two groups.. Heat and no heat. But I'm having trouble finding out if some of them benefit from heat or not?? The ambient room temp is about 68... (so under the lights I generally say about 70).. But I have a heat mat I usually put around 80-85.
Here are the ones I'm not sure of.. so if you have advice , I'd love it.
Allyssum Royal Carpet and Carpet of Snow
Gypsophila (Baby's Breath)
Salvia Bonfire (red annual)
Pansy (I'm pretty sure they don't need heat)
I would go by the suggested seed starting date related to the "last frost". If it is a short time, then I would say they would benefit from heat. If you are told to start the seed many weeks before the last frost date they are pretty hardy and don't need heat. I don't think this means that heat would hurt it, or not accelerate the germination. And if you use grow lights they will get some warmth from that. This is a somewhat experienced guess, so I will follow this thread to see what more experienced gardeners weigh in on. By the way one of my sources that I check to plan dates for starting is Park's seed catalog; they have a 2 great pages in the center of the catalog that gives a lot of useful information like germination time, light or dark requirements, and categorizes all the flower seeds in the current catalog. Not perfect but I find it helpful.
I agree----heat mats not required for any of those.
It is usually the more tropical plants which need higher germination temperatures.
They will all do well under lights only.
Alyssum and pansies like cooler temperatures after germination,
- so I would keep them
further from the heat of the lights.