Tree and Shrub Winter Update

Dealing With Freeze Damage
Facts and corrective actions

It is not uncommon for late winter and early spring temperatures in the Southeast to be 70 degrees for several days, and then suddenly drop to below freezing. When the temperatures rise, many plants will begin to bud with new growth. Unfortunately this new growth is often killed by frosts that come afterwards.

New plant growth contains a good amount of water. When the temperatures freeze, the water held in the new growth freezes, and this causes irreparable damage to the cells of the new growth. Plant material that is freeze damaged will curl and turn dark brown or black in color. Not only can the new leaves be damaged, but the stems of the new material can become dark and brittle if affected by freeze damage.

There are several protective measures that can be taken to help avoid freeze damage to your plants. Unfortunately you cannot go outside and tell them not to grow; they do not listen too well. You can, however, use items such as frost cloth, burlap, old sheets, plastic drop cloths, and cardboard boxes to help protect your plants from a coming freeze. Exposure to wind chill is what causes the most damage to plants, and these items will help keep the wind off your plant material. It is VERY IMPORTANT that you remove this protective material the next day.

You may have plant material that is simply to large or too tall to effectively cover, and damage will most likely occur. This is not as bad as it seems. Freeze damage normally occurs on new growth, and this damaged material can simply be pruned off later in the spring. DO NOT prune immediately, however. Leave the damaged material on your plants until there is no more reasonable chance for freezing weather. The dead material at the tips will prevent the plant from producing more new premature growth, and it will also insulate the rest of the plant.

In some severe cases you may find the bark on some of the newer, smaller limbs will be split by the freezing temperatures. This can cause the material on the entire limb to die. Just as with the damaged leaf and stem material, you should wait to prune it out until after there is no more reasonable chance of freezing weather.

 

Pruning
Winter is the best time to do it

Our tree and shrub treatments along with your watering practices go a long way toward making your landscape look beautiful. But plant material that has been installed for more than 3 years will need to be pruned in order to keep it growing properly and keep it healthy.

Winter is the best time to heavily prune your landscape because the sap is low and the plants are either dormant or in a state of slow activity. The exceptions to this rule are plants that will be blooming in the spring. Pruning them in the winter will reduce the spring bloom potential. However, spring bloomers like azaleas and rhododendrons that are grossly overgrown and need severe pruning should be pruned in the winter in order to minimize the shock that can occur when they are more actively growing.

To properly prune your landscape, begin by choosing the proper tools. You can choose anything from scissors to hand shears to loppers and saws. Be sure your pruning tools are sharp, sterile, and in good repair. Always make a clean, deliberate cut to allow for the best possibility of healing.

Begin pruning your plants by removing dead, diseased, and excessive branches inside the canopy. Remove sucker growth next, and then you can begin pruning for growth and aesthetic appeal. Be sure to get a good mental picture of what the plant is going to look like BEFORE you make a cut. You cannot put it back once you cut it!

Specific placement of your cuts will depend on the location on the plant and the purpose for removing the material. When removing sucker growth or interior branches, make the cut slightly out from the stem or branch from which it is being removed. Never make a cut that is flush with the bark. Also, keep your cut at an angle, not shallow or blunt. If you want to promote additional growth, make your cuts at a 45 degree angle about 1/4 inch above a healthy bud (see illustration). By doing this, you will encourage growth from the buds below your cut.