20 degrees and orange trees? How protect?

I have 3 small (about 5') orange satsuma trees, they have gone all winter with no covering. I'm in mild zone 8B climate, but they have sustained low 30's weather, and a little frost.

Do I have to protect them? And is a sheet enough? Should I use something thicker? How about one of those plastic blue paint tarps? They are light yet thick. These are very young and small trees so they can't take a very heavy covering.

I'd use burlap as it soaks up any dew which combined with frost can damage. You can also use a sheet of corrugated fiberglass bent over the plant. The paint tarp works but holds in moisture and doesn't breath. It might do the trick for a night or so.

It's supposed to be colder tonigh. Drive 4 stakes around each tree, leaving enough room between the stakes and the tree to make sure the cover doesn't touch the leaves. Take out outdoor Christmas tree lights and wind them throughout the trees letting some lights hang down below the tree line, but in contact with the ground or dirt. You could also use C7's but don't let the lights come in contact with living tissue. Then drape plastic, old blankets, burlap over the top. If you use plastic you can leave it on during the day if you open up a side or two to let the heat that builds up during the day escape. Any other cover would have to be removed during the day. Although it wouldn't hurt the tree to leave the cover on for a day or two if the weather remains very cold. For a sturdier plant frame, make the frame from 1 X 2's putting it together with nuts and screws (Makes it easier to take apart after the last freeze.) One of my citrus book says that a floodlight can be used as well.

Betty, thanks. What is the purpose of the Christmas lights? Surely not for extra warmth. I only have the tiny lights, not the larger (nightline sized) bulbs, if they are for the purpose of warmth I can't see that helping much. But I will take your word for it. :o)

The Christmas tree lights really work. Follow what bettydee said if you are in a position to do so.

Yes, the Christmas tree lights are for warmth.

Down here in fla they spray the trees with water and it freezes and that protects the trees in winter. Fran

Fran, hubby told me about that, I guess I didn't really believe him. But if it is going to freeze overnight, say by 2 am, then I wouldn't think that a watering several hours earlier would help...........does it????????????

The way the water helps keep temps up is by freezing. When water is at 0C/32F, it can exist as either liquid or solid. For the lattice of ice to form, the molecules of water have to give off a bunch of heat. So the act of freezing liberates many kilocalories of heat. Constantly applied, the water forms an icicle around the tree and warms the air. That alone will help some, but if a constant mist can be added to the mix, temps will be bouyed to where the tree survives.

Smudge pots also help. The smoke from the burning fuel lowers the temp at which ice will form. All of those particles with their attendant brownian motion does what adding salt to water does, but not quite so well. With a smudge pot, you can easily get 3 or 4 degrees F protection, which means your trees will be protected to about 28F/-2C ambient air temperature.