Cold Weather Tips - Protect Your Plants from a Cold Snap

Which Plants Need Protection? 

Tender plants, immature plants, new growth and blooms need the most protection. Here's a list of some that you should plant to protect from frost: 

  • Tropicals and houseplants 
  • Most annuals (some like pansies & violas tolerate cold and freeze easily)
  • Trees and shrubs with blooms, flower buds, and/or new growth (the plants will weather the freeze just fine, but blooms and new growth will be damaged if not protected & you'll have to cut it back to let the plant recover)

Which Plants Tolerate Our Climate? 

The easiest way to know what grows best in our region is to know our hardiness zone according the USDA Plant Hardiness Map (7b and 8a in the Atlanta and Charlotte areas). Plants that thrive in the northern hardiness zones can weather a freeze/frost more easily.  If you’ve planted summer plants that usually thrive better in more southern zones, then those will be the ones that need protection more than others during a freeze (mostly annuals). 

How Do I Protect Them? 

  • Move: Move your potted plants indoors or to a protected area like a garage or shed.
  • Water: Water your trees and shrubs prior to sunset before the frost. The added moisture helps hold heat in the soil so the plants' roots can better tolerate the cold. Be sure to water the SOIL, not the leaves or stems. For annuals, perennials, herbs and veggies, leave them dry; they tend to handle extreme cold better if they are drier. 
  • Mulch: Mulching your garden insulates the soil and retains soil moisture, which helps regulate ground temperatures during a freeze. Your garden should have a 1-2 inch layer of mulch. 
  • Cover: Place a frost cloth on the plants prior to sunset before the frost to help trap in the warmth from the soil and protect them from wind. Ideally, frost cloth should not touch foliage. Secure the frost cloth with stakes, rocks or bricks so wind doesn't blow it off. It's important that you remove the frost cloth first thing in the morning so that the cloth does not trap in the heat from the sun and cause damage. 
  • Wash: Any plants that you can't cover to protect from frost can be washed at sunrise after the cold snap. Use a hose to gently spray them with water BEFORE the sun comes out. This will help minimize frost damage by melting the ice as quickly as possible. 

Assessing Cold Damage 

  • Be patient: You can’t tell the extent of the cold damage until a plant starts actively leafing out/growing in Spring.
  • Be on the lookout: Watch for signs of new growth throughout the plant. Depending on the plant, you may not see leafing out until early April. 
  • Try the Scratch Test: Another way to see if a plant will spring back to life is to lightly scratch the bark and look for fresh, lighter-colored wood. If you scratch the branch and the color is the same without any sap, then it is likely dead from the damage.

Treating Cold Damaged Plants

  • Fertilize: Once a plant starts leafing out, start a fertilizing program with an all-purpose fertilizer to improve root health.
  • Prune: If you had branches that broke during the icy weather, prune them so they have a clean cut to heal properly.