Just a few days ago it was 85 degrees here. Tonight they are forecasting 25 degrees and a heavy frost. It usually wouldn't even cause me concern, I do live in Kansas afterall, but I just put some of my vegetables in the Lasagna Garden earlier this week.
I've been scurrying around trying to figure out how to protect my plants from the frost and thought you might need to know as well.
It seems that there are a couple of things that happen when it gets too cold for your plants. First of all when frost accumulates on the leaves it burns them and then those leaves die. I've read that you should just leave those leaves on the plant and they will be replaced by new ones.
Then when it gets really cold, considered below 28 degrees fahrenheit, the water in the leaves and stems of your plants actually freezes and that's not good for a plant.
So let's talk about how to keep your plants from getting "frost bite" and freezing.
There are a number of ways you can go about this, some are easy and some are, well, they are all pretty easy!
Put something over your plants. You can use any number of things from old sheets, newspaper, burlap. It's best if you can put something in the garden to keep the sheets from touching your plants, you can use anything to do this, tomato cages, coffee cans, a stake, anything that will keep your cover off your plants.
If you can't get this done, just gently lay the cover over your plants. This will keep the frost from touching the leaves of your plants.
You can also use empty plant pots or buckets to cover your plants. I had a big galvanized bucket that covered three of my cauliflower plants, and I had a couple old 5 gallon buckets that worked well over tomato plants as well. For some smaller plants I had a some empty plant pots from lasts years annuals. (my husband keeps telling me there's no use for those empty pots and to throw them away~ ha!) This worked really well for me.
It's important to take your cover off the plants in the morning as they need air and sun during the day. Even if your forecast calls for a few consecutive nights of below freezing temperatures make sure to take the covers off during the day and replace them at night.
If it's going to be really cold you can put a bucket or jug of water out in the garden during the day to collect some heat. Water releases heat slower than soil and air, so if you have the jug under your cover it will maintain a little heat throughout the night so your plants won't freeze.
Those are some basic tips to help protect your plants from a spring freeze. Remember, though that the best way to protect your plants is not to put them out until after the last threat of freeze. Here's a chart to help you figure out when you last freeze will be.