Temps during the day have been in the fifties and sixties, and nights have been in the forties. Last night the temperatures were predicted to get to 28 degrees or lower. This means that there was a freeze warning for last night. I found this description on the net:
Both [the frost advisory and the freeze warning] are only issued during the growing season. A Frost Advisory is issued when the predicted temperature is expected to fall to 36 degrees or lower in the next 3 to 30 hours during the growing season. So temperatures 35 to 40 range would also dictate a frost advisory. A Freeze Warningis issued when there is an 80% or greater chance that the temperatures are expected to fall
to 32 degrees (F) or lower in the next 3 to 30 hours during the growing season. If the temperature is expected to fall below 28 degrees (F) this is considered a Hard Freeze.
Since I am in the city and my neighborhood is on a slight hill, I usually assume my yard will be about 3 to 5 degrees warmer. Even so, I could expect a good freeze or at least a hard frost.
If the temperature had been only cool enough for a light frost, I would have crossed my fingers and let the garden sort itself out, since the early plants are all pretty hardy. What I have planted so far are pretty frost tolerant, but even so, temperatures that low could still do some damage, so I broke out the plastic.
Danny and I put props in the beds that didn't have tall supports. Any leaves touching the plastic could get frozen, so we had to prop the plastic up away from the baby plants. We got them covered by about 5 pm. This time of year my yard is in shade by about 7 pm, so the beds had a couple of hours to warm in the tents be
fore the sun went down.
This morning I went out before the shade left the yard to open the tents, since I didn't want the plants to overheat in the plastic with the sun. As I opened each one, a puff of warm air escaped, so I knew the plants had been toasty all night. The only casualty was a volunteer pansy that was near an opening in the plastic. It had frozen and wilted.I left the plastic out for the day. Tonight is going to be a little warmer, but tomorrow night is supposed to be in the low 30's again, so I will be covering them for that.