It may require some work, but there are things you can do to protect your plants from the freezing temperatures this weekend.
Experts from Gardener's World in Phoenix say covering your plants is the first step.
They recommend using a frost blanket on all of your sensitive plants. This material is designed to provide seven to ten degrees of frost protection. They say you should not use materials such as burlap, tarps, or other plastics because they do not provide the same warmth and can often be heavy, not allowing your plants to breath.
They also advise against using sheets to cover your plants because they are not warm enough. However, if sheets are your only option, then you should think layers and use several sheets per plant.
Another option for plant protection is a liquid polymer that you can find at your local nursery or hardware store. The non-toxic liquid will help protect your plants from freezing by giving them an additional five degrees of protection. All you have to do is spray it on the leaves 24 to 48 hours ahead of when the freeze is forecast.
With temperatures forecast to drop below freezing for possibly several hours this weekend, citrus and fruit trees are also in danger. Unfortunately, Gardener's World experts say covering these types of plants may not be enough to protect them from damage. They say your best option might be to just pick all of the fruit before the weekend, otherwise, you run the risk of losing it. Experts say the damage on the fruit could be similar to freezer burn.
If your plants already have some frost damage from past cold temperatures, experts say DO NOT prune them. Removing the damaged ends will only leave the healthy parts of the plant exposed to future frost/freeze damage. Instead wait until about the middle of March to start pruning.
Here's a list of frost sensitive plants:
Thevetia (Lucky Nut Tree)
All varieties of Carissa (Natal Plum)
Tecomaria (Cape Honeysuckle)
Tecoma (Yellow & Orange Bells)
Passiflora (Passion Flower)
Senecio (Mexican Flame Vine)
Solanum (Potato Bush/Vine)
Cuphea (Mexican Heather)