[metmom]

We had an unexpected light frost last night, but, the plants I’d put out uncovered seem ok, except the most exposed tomato, an “Early Girl” I’d overwintered indoors, and then taken out a few days ago. Some leaves seem damaged — I’ll know for sure in a day or two. My fault for not being more cautious, but NWS had said 40 deg., not 37 deg.

Our area always runs cool so when it says a low of 35, I still cover everything or bring the seedlings inside.

[Paul R.]

According to NWS, we got down to 37 deg. F, and we had frost in top of our (dark blue) Chevy Tahoe parked away from the house. The thermometer in the Tahoe is pretty accurate when the vehicle has been setting a while in no sun, and not running, and it read 38 deg.

I’ve seen frost form on black plastic over plants, with air temps of around 37-38 deg., in very calm conditions too. Radiational cooling...

Usually, anything under 40 deg. F and “calm” prompts me to cover even adult plants. But, the forecast was for 40 deg. and I was lazy... :-(