by Brandi Eide
As you bundle up to stay warm this winter, don’t forget about your plants. Some of them benefit from extra protection when the temperatures dip. Look up your city’s average frost dates to know when to expect frost.
If you are uncertain, check species online to determine their winter hardiness. Yards often have different microclimates; plants have some protection when placed under trees and shrubs, patios, and next to homes or walls that heat up during the day.
Shrubs sheared into unnatural shapes or those over-pruned are more susceptible to frost damage. Avoid applying fertilizer later in the year, it encourages tender growth sensitive to frost.
Water leafy plants before a freeze; their hydrated leaves will then better tolerate the ice crystals that form and draw moisture from the leaf tissue. Succulents are just the opposite: keep them drier during cold months, water infrequently or not at all. (There are winter growing succulents, with varying temperature sensitivities, but most landscape succulents in the southwest are summer growers and should remain dry in winter while dormant).
Cover sensitive plants with frost cloth, sheets or any fabric light enough not to crush a plant, or construct a framework around delicate plants with poles, PVC or tomato cages to support a heavier fabric. Frost cloth is a lightweight cloth that can be found in at least 4 different weights which increase temperatures by around 4-10°F if used correctly; it allows a fair amount of light to reach plants, therefore it can be left on for several weeks. Apply plant coverings like a tent: draped to the ground and held/staked there. This captures the warmth radiating from the ground and keeps out cool air that sinks to the ground at night. Don’t wrap fabric around shrubs or trees like a lollipop wrapper. While this offers some protection, it is far less effective than tenting. Use supports with plastic sheeting to keep it from touching plant material as it can otherwise cause more damage than good.
Some columnar cactus are tall or too challenging to cover. In this event, place Styrofoam cups over the tips of the stems for protection. In a pinch, use large plant containers, buckets or trash barrels to cover larger succulents overnight.
No matter what solution you use, leave the materials on for a short period of time. You can use fabrics for a few weeks and buckets overnight or a few days.
Frost cloth is a hot commodity right before a freeze. Don’t wait until the weather forecast predicts freezing temperatures to gather necessary supplies. Plan ahead, order supplies from your local nursery or online and be ready for cold evenings. Alternately, know the frost tolerance of the plants you purchase. With careful selection and plant placement for your climate, (consider both winter and summer exposure), you can often avoid the need for winter protection.
If your plants show signs of frost damage, resist the urge to prune until the danger of frost has passed. Dead foliage continues to protect the inner parts of the plant through winter. Some plants die back to the ground entirely, wait until spring to determine which plants need to be replaced and which require a rejuvenation pruning.
For useful information about desert gardening, visit the Springs Preserve Garden in Las Vegas or visit us online at springspreserve.org.
~Photography by Springs Preserve