The chilly weather and frost that has already reached the Midwest will probably give the mid-Atlantic and the Northeast a chill with frost overnight tonight (Saturday). So, it starts again!
Clear skies make frost more likely. The reason is that clouds act as barriers to the loss of heat. Clear skies let heat go.
My containers are on my second-floor porch, so that will help protect my herbs and flowers there. Heat rises, and frost usually forms closer to the ground. I may still cover them.
My garden plot doesn't have the same protection. The wind or breeze can carry heat away horizontally with little interuption. Clear skies also allow heat to escape vertically.
Numerous types of frost can form: Heavy, light, scattered, killing, and so on. Even hoar frost that Robert Frost wrote of in verse. It's still early, so in most of the mid-Atlantic the frost will probably not be severe.
The susceptibility of plants should also be taken into consideration. This year was dry, making the plants more fragile. Some types of plants cannot handle a chill, let alone a mild frost.
I just reviewed a forecast for Sebring, Florida (at my job). Sebring's high Sunday will be 91, then a low of 71. Bellefonte's will be 67 for the high Sunday (not too bad). What follows is the undesirable part: a cold low of 41.
Frost Protection Advice:
P Allen Smith