Tomato Seed Starting Temps

[loulac]

RayR quite rightly insists : soil temperature is the important factor in germination.

Most visitors here rightly replaced air by soil in the poll. The temperature of the seed seems to be the only element to take into account. As it is only about 1mm (metric) under the surface it may be influenced by air temperature but only partially.

I'm quite impressed by Joseph's equipment. Really first class. Yet I would replace the fan by a heating mat. Any kind of cover (plastic sheet etc) covering the starting setup would keep air temperature at a satisfactory level.

Besides all seeds don't germinate at the same speed, at the same temperature, so giving a general rule seems very difficult...