Here in Prescott, where the average elevation is about 5,370 feet above mean sea level, the first fall frost can occur as early as October 15th, and the last spring frost can be as late as May 6th. It is important to have items on hand to protect your sensitive plants or trees from frostbite.
Frost cloths or blankets can be pricey but may be worth the investment if you intend to live here for many years. The smallest 6’ round blanket is about $11, while a larger 10’x20’ blanket is about $21. If you are protecting a garden, you might consider purchasing a 110’x5’ blanket for about $36.
- Of course, you may choose to use old sheets and blankets and do your best to cover the plants using clips or safety pins. Burlap bags may be used but be careful not to weigh down the plant. It is best if the cover reaches the ground, which will trap the warm air rising from the soil.
- DO NOT Use a plastic shower curtain or tablecloth. Plastic will freeze and transfer the cold, either burning or killing the plant.
If you leave early for work, do not bother to remove the covers. It is still too cold and you will defeat the purpose. If freezing temperatures are predicted throughout the week, leave the blankets in place.
- If you still have old-fashioned Christmas lights handy, place them near the base of the plant. As heat rises, it will help to warm the plant. Newer LED lights, however, do not create heat.
- If the forecast calls for a cold night, TURN OFF your automatic sprinklers. Wet leaves and stalks will freeze and kill the plants. DO NOT water cactus or succulents; they will withstand the cold better if the soil is dry. Shrubs that are shaped into balls, squares, and triangles are more sensitive than plants allowed to grow into their natural shapes.
- Potted plants and hanging baskets are susceptible to cold weather. Move them inside or into a garage or shed. Place Styrofoam cups on the ends of columnar cactus arms to protect growing tips.
- Wrap the trunks of young trees to provide another layer of protection.
Plants and trees damaged by the cold will still help to insulate the plant from further damage. Wait until Spring, when the nights begin to warm up, to trim away the brown parts.