After 7 days of Paper Towel Germinating?

[zeroma]

Got started last week with PTG. Tomatoes only. Less than 2 days and 2 seeds of the same variety had germinated! Happy dance. Fastest I've ever had seeds sprout.

Within 4 days I got 11 total out of 40 seeds. 9 different varieties.

Now nothing has sprouted for last 4 days.

One thought is they got too hot from the heating mat. In past year, I usually just use the room temperature inside my house which has worked great.

This year I'm giving one of the seed starting kits the community garden bought, which includes a heating pad.

There is no temperature control dial, so don't know what the temp actually is.

After nothing happened, I placed a terry towel on top of the heating pad, placed the baggies back thinking maybe it was too hot for them. I check them each day, add a bit more moisture as needed, opening them to give them more oxygen, what I've always done with great results.

I restarted more seeds yesterday. Plus I covered the baggies up with an upside down standard black growing tray to block out all daylight.

Too much heat and not dark enough along with maybe just not enough time yet are the only things I can think of...just got the seeds, some were 'gifts' and older, from 2013, but I've had good luck with 7 and 8 year old seed in the past

How much time do you all give seeds when you are pregerminating them before just pitching them?

Z