Frost and Your Plants

Depending on where you live in Maricopa County, you can expect frost from the end of November until as late as April in certain areas. The record low in Phoenix was set in 1913 at a frigid 16 ° F. Recent low temperatures have resulted in frost damage to plants in our area.

If your plants have already experienced frost damage the most important thing to remember – don’t prune them yet! Pruning may stimulate new growth which could be damaged by a later frost. Wait until danger of frost has passed and the plants have begun their spring growth.

To protect your plants from potential frost, keep them well-watered, and keeping the moisture level in your irrigation system as consistent as possible. Cover plants with cloth or paper (sheets, blankets or frost cloth). Keep plants cozy and fully covered with no gaps for warmth to escape. Don’t gather your covering around the base of the plant, but allow it to extend out to the ground at the drip line. This will trap the heat being radiated from the ground. When covering plants with sheets or blankets, remove the coverings daily so that the plant doesn’t break dormancy and start to actively grow too soon.

You can wrap the trunks of young citrus and other frost sensitive trees with multiple layers of weatherproof paper or cloth. Make sure your wrapping extends from the ground up to the lower limbs to protect the tree’s vital area.

The easiest ways to minimize frost damage to plants is to select frost tolerant plants, and to place frost sensitive plants in sheltered locations.