I live in a warm microclimate so, if it says it's going to be a low of 40, I don't cover.

I would cover them. It may seem like a waste of time, but it's much easier than replacing plants later.

Leslie

I live in a cold microclimate and often see frost when we have a 40 degree local forecast.

You can work all spring and then lose almost everything to a stray frost.

I agree that it is safer to cover them. Frost can occur at 40 degrees though it doesn't always.

I didn't even uncover anything today. I've left the plants covered up for as long as 3 days at a time this year. In 2007, I had to build low tunnels over 7 planted beds and keep them there for 3 weeks after a big cold front arrive in April and brought cold temperatures, sleet and a bit of snow. The low tunnels were like mini-greenhouses so the plants grew great inside of them even though it was cold outside.

Any time I am pondering whether or not to cover up the plants on a given night, I ask myself how I would feel the next morning if I walked outside and everything was frozen or frosted. That thought sends me out to cover up plants every time because it is not fun to walk outside and find dead plants.

One night last week I didn't cover up my plants. The forecast was for 46, and we awakened to 40 and patchy frost. My tomato plants weren't damaged, but I was nervous when I saw how cold it had gotten. Some potatoes were damaged but they were growing in a slightly more open and exposed area.

When I cover things up, what I am thinking is that I don't want to lose all the $ invested in the garden thus far by not getting a harvest. Tim looks at it differently--he says he sees how hard I work in the garden and he doesn't want me to lose the time and work invested in it. Either way, we both think it pays off to cover it up when we are home and are able to do so.

As an example of why you shouldnt risk it: My forecast low was 38 last night. Our actual low was 31.

Leslie

Larry,

The same thing occurred here. Our forecast was for 39 and we went to 33 at our house (and 29 at our mesonet station)and have a very heavy frost today, much heavier than yesterday and not patchy at all....solidly spread about everywhere.

You know that if it went to 33 degrees on my thermometer 5' above ground that at the ground level it likely was below 32. I should have uncovered one plant and left it uncovered last night to see if it would freeze. I think you and I both know it would have.

Dawn