December 2011

Frost season in the Southwest typically runs mid-November through February. The frequency and intensity of frost can vary during this time of year due to a number of reasons, including elevation and population density.

	Native vs. Non-Native Plants Plant native plants. Selecting plants native to our environment is your first line of defense in preventing frost damage. Non-native plants may not be as tolerant of this climate. Select western and southern exposure planting areas for frost-sensitive plants. If you do select frost-sensitive plants, plant them near block walls, rocks and patios; rocks absorb heat from the sun and maintain a warmer temperature through the night.
	When Frost is Predicted Cover bare soil with mulch to create a barrier between the frost and your planting area. Cover plants susceptible to frost-damage with cloth towels, blankets, sheets or paper/cardboard boxes to insulate them. Drape the paper or cloth all the way to the ground to help trap heat radiating from the ground under the cover. A nursery can help you identify material made specifically for covering plants. Remove the cover after sunrise each morning or when the temperature reaches 35 degrees.
	Protect Your Backflow Prevention Device The easiest way to protect your backflow preventer is to cover it with a towel or blanket. You can also drain the water from your backflow by shutting off the first shut off valve where water enters the unit and opening one of the test cocks with a small screw driver to drain the water. Remember to disconnect your hoses from hose bibs. Additionally, any above ground plumbing should be protected when frost is predicted.
	Prune or Not to Prune? If frost impacts your plant material, it is optimal to wait until the threat of frost is gone to prune frost-damaged plants. New and un-established shrubs or ground cover plants are more susceptible to permanent damage and could be lost due to cold weather. Pruning away frost damage too early can result in additional damage to the plant if it is hit by frost again. Established plants with a sustainable root system can handle minimal pruning for aesthetic reasons throughout frost season.

To learn more about common area planting, request a proposal for plant installation or common areas maintenance, or learn more about DLC Resources, email Rebecca Herro (RebeccaH@dlcresources.com).

For more information on desert landscape and plant care, check out Arizona Cooperative Extention. If you reside elsewhere in the southwest, contact your local Cooperative Extension office.