I forgot to post a few weeks ago... about how I cover my orange trees for pending frost. So here it is.
Drive a bamboo stake (or any other material) into the centered top .....to the the ground. Have the stake in the soil two or three inches, this is to act as an anchor. The top should be 6 inches above the tree.
Next....loosely attached a 6 inch plastic tie encircling the bamboo stake and the tree trunk, this keeps the stake in an upward position. Make sure that these ties are cut off in the Spring.....otherwise the tie will strangle the tree as it grows. Dead trees don't produce much fruit.
Now that you have a "tent pole", throw two burlap covers over. One big piece followed by a smaller "cap" as seen in the picture above. I have found that double layered burlap will protect the trees far better. These covers by the way, can be purchased at Home Depot for about six bucks each. Their measurement is 40 inches by 40 inches.
If it looks as though it there will be frost all week long......just leave the covers on. I had covers on the trees last year for over eleven days. An hour each day multiplied by eleven days .......that's a lot of time saved. Make sure that the covers are dry before taking off and putting into storage. A minute amount of moister will certainly rot the burlap. I'm telling you this from my prior experience :-(