Just curious what kind of containers you're using. I use milk jugs that are in full sun (when it's not snowing or raining or overcast which it has been until the last week or so). I haven't had to water yet. Are you using something shallow?

I use milk jugs too. About 3 inches of soil.

I water when the top gets dry.

The ones that are in full sun, are also against a brick wall, so that probably makes them hotter. I am now putting them in dappled sun/shade, and that works better, stay moist longer.

By dry do you mean when you no longer see condensation? I have a few jugs like that, but when I stuck my finger in the soil it was still moist. I've been known to drown plants in the past, though, so I err on less rather than more. I did water the lettuce and kale the other day, but I took those tops off about a week ago since they like it cool.

I go by weight and appearance. If the soil looks dry on top, I plop them in some water.
I can also pretty much tell by lifting them if they need water.

The warmth of full sun definitely speeds germination. I also think it prevents some of the rotting, if they aren't quite as wet as they might stay in the shade. I keep mine in the shade through winter, but when the snow is gone I move them into the sun to get things moving.

Martha