Will winter ever arrive? Someone needs to remind Mother Nature that the Desert Southwest wants to experience cooler temperatures at some point. With all our warm fall, plants that normally go dormant have continued to grow, putting some frost-sensitive plants at risk of freezing back when our winter finally does arrive. A plant’s ‘hardiness’ is its cold temperature threshold: the more ‘hardy’ the plant is, the more tolerant it is to cold temperatures. Here are some frost facts to know when preparing your landscape for the (possibly) cold Arizona winters:
There are a number of frost protection strategies, including frost blankets, anti-transpirant foliar sprays and even Christmas lights can warm cold-sensitive plants. Frost blankets seem to be the favorite choice in our region, providing up to 8-9 degrees of protection. However, they are often used incorrectly, just covering the top of the plant, which unfortunately does not provide any protection from the cold. Here are a few helpful hints to make sure you are using protective frost blankets correctly:
Sheets or blankets, should be removed daily
Frost cloth can be left on for a few days
Christmas lights at bottom of plant can radiate heat
Water under canopy adds heat: when water cools, energy is released=heat!
Don’t fertilize- new growth is more sensitive to frost damage
Don’t prune- don’t prune sensitive plants until after threat of frost (late February)
Don’t overprotect- allow plants to harden off, gradually expose to cold weather