The recent minus degree weather here in the Southwest has done damage to numerous plant life.
Here is a list of what some will and will not do.
Most well established trees 5 years or older that went into dormancy stage (loss of leaves) will most likely come back with no problems. Exceptions: Palo Verdes, Eucalyptus, and possibly the Carolina Laurel's. Mesquite and Chilean trees should survive.
Junipers and Cypresses bush, trees and shrubs should have no problem. Most will probably turn a reddish color but the green color will return with warmer weather.
Lantanas: If you didn't cut back and cover heavily during Nov-Dec that chances that they will come back are nil.
Palm Trees: California, Mediterrean, and Mexican Fan Palms took a big hit...most likely you will have to replace them. If they have been there for more than 5 years I would wait to see if they show signs of life in Early April.
Some that were protected by other trees or plants might come back. Sago palms will most likely have to be replaced.
Mock Orange (pittosporum) probably will not come back. If they look red or a brownish color they will have to be replaced.
Wax Leaf Privets will survive the below zero degree weather. As will Most Hollies and India Hawthrone.
Cactus: Most will not survive and will have to be cut back considerably or possibly remove altogether. This includes agave plants. Most outdoor varieties of Yucca plants should survive.
Lawns: Bermuda should have no problem coming back but the process of turning green will be delayed. Fescue and Kentucky Blue grasses will look bad until early spring.
Roses: If you haven't already cut them back to about a 1/3 of the way down. Most roses are semi dormant in this part of the country. But, the weather last week has probably made most roses go completely dormant.
All pine trees such as the Eldrica, Aleppo, Italian Stone, and the Colorado Spruce trees will have no problem with the deep freeze temps.
We are still in the Winter season...use common sense when planting right now. Pay attention to the weather...predicting the weather is a complicated process and many times weathermen, TV and radio stations do not always get it right.
Cover your plants with thermal plant blankets most nurseries should have this product in stock. If not...tell them to get some.