In every part of gardening, there are inevitably setbacks when you try something new. My fancy seed-starting setup started off great, producing healthy onion seedlings and quickly sprouting lettuce and kale seeds. But the peas refused to come up. And when I poked in the dirt atop the latter, I discovered that every single seed had rotted in the ground.

Putting on my thinking cap, I came up with three potential problems. Possibility one --- peas hate stump dirt. Possibility two --- the year-old pea seeds just weren't viable. Or --- the possibility I suspected was actually the most relevant --- our new heating mats exceeded the maximum germination temperature for these cold-weather legumes.

The trouble was, I bought a cheap seed mat without a thermostat, and I soon found that the device runs a little hotter than the heating pad I'd been using previously. On a warm day with the heating mat on, soil temperature was right at 85, compared to a non-heated tray that clocked in closer to 72. Sure enough, 85 is listed as the maximum germination temperature for peas.

To test this hypothesis, I started another round of pea seeds, this time off the heating mat but using seeds from the same packet planted in the same stump dirt. Sure enough, three days later, this second round of peas had broken dormancy and were sending down roots. Success!

Moral of the story: keep peas off the heating mat but put everything else on the heating mat until they sprout. I'm curious to see what my new setup teaches me next.