Symptoms of freeze damage include shriveling and browning or blackening of damaged tissue. Damaged growth usually becomes limp. Eventually, damaged or destroyed leaves drop from the tree or shrub. Fortunately, trees and shrubs have the ability to leaf out again if the initial growth is damaged or destroyed.
Damage may look severe, but plants will usually recover.
The signs of of freeze damage are evident on many plants but do not always look the same. On tropical and sub tropicals they may appear droopy or shriveled, like they are in need of water. Additionally they may turn for green to brown or purple, and stem splitting may happen.
Wait until the final frost in your area to prune frost-damaged plants. Ensure that the cold weather has passed for the season because early pruning can prevent the new season's growth from occurring, as pruning stimulates new growth.
While you may be eager to remove cold-damaged foliage from your garden, the best course of action is to wait until spring to do any pruning. We will not know the extent of damage until new growth emerges. By pruning too early, we risk cutting out plant tissues are still living and will recover.
During excessively cold temperatures
It's minor, but it could impact the look of a plant or create a haven for insects and diseases later. Don't prune when the temperature falls below 25°F.
As mentioned earlier, watering plants several hours before a freeze is the first defense against damage. During a temporary cold snap, cover entire shrubs with burlap, sheets or blankets for insulation. For the best protection, use a frame to prevent the covering from touching the plants.
Thankfully, the answer is often yes. Whether they were damaged in a drought or a hard overnight freeze, most regional trees, shrubs and flowers can be nursed back to vitality – if you know how. When considering how to bring your shrubs back to life, it is important to determine the cause of the blight.
Thoroughly Water plants if it's not going to rain before the freezing temperatures arrive. It may sound illogical. However, a moist ground stays warmer than dry soil. Watering the night before the freeze comes will insulate the root structure of the grass and plants and decreases the potential for cold injury.
As winter progresses, the ground freezes and the sun and wind evaporate more water from the leaves or needles than the plant can uptake to replace it, and the plant gradually turns from green to brown, bronze, or even orange or purple.
Identifying Frost Damage on Plants
You will likely notice first signs of damage more clearly the day after a frost on the most exposed plant parts and those with the softest tissues. Leaves, new shoots, and buds turn limp, dry, distorted and yellow, brown, or black in color. Flowers wilt and shrivel.
Deep water plants before ground freeze, and continue to water during winter months when temperatures remain above freezing but without precipitation, Erect physical windbreaks. Wrap problem plants with burlap or other material to protect from wind and subsequent moisture loss to evergreen shrubs and small trees.
While the damage to the leaves is permanent, plants are pretty resilient. If the leaves are severely damaged, they will die and fall off. New leaves should take their place. It may take several weeks or months to see full recovery, but given warmth, proper light and water, most plants bounce right back.
It is best to water in the afternoon or evening the day after a freeze so plants have had a chance to slowly raise their temperature. After a freeze, soft-stemmed, non-woody plants such as impatiens, cannas, elephant ears, agapanthus, amaryllis, begonias, philodendron and gingers may be pruned back to living tissue.
If they're all green and moist under the bark, your shrub's in good shape. On the other hand, branches that are brown and dry below the surface are dead, and lots of dead branches likely mean the shrub won't survive.
For shrubs that suffered die back – that is, there's growth coming in on some part of the plant, but not all of it - cut off the dead stems to just above some vigorous new growth. Don't be afraid to remove small, spindly growth if there are bigger, healthier buds growing below.
If your shrub turned brown due to extreme heat, start by watering the roots slowly. The good news is that many times, shrubs do bounce back. However, whether or not your shrub can be revived will largely have to do with what caused it to turn brown in the first place.
Winter is usually the best time.
If you live in an area with distinct winters, the time when shrubs have lost their leaves and become dormant is an excellent time to prune them. Without the leaves, you can easily see the branching structure of the shrub and decide what to cut.
Know Your Plants' Cold Tolerance
Some frost-tender plants need to be covered as soon as the temperature hits 32°F, while others can handle lower temperatures and/or longer freezing periods. You'll need to look up each of your plants to verify its cold tolerance.
Just like humans, plants get cold and need protection from frigid temperatures. Evergreen shrubs can withstand flurries, but heavy snow and other hazards of the upcoming season can wreak havoc on these workhorse yard plantings.
After “how?", the second most-asked question we get about pruning is “when?” (Or, "Can I prune this now?") The rule of thumb is to prune immediately after bloom for flowering shrubs, in late winter or early spring for non-blooming shrubs (particularly for heavy pruning), and not after mid-August for any shrubs.
As a general rule, a light summer pruning can be performed on most deciduous trees and shrubs. Heavier pruning should be performed when the tree is dormant, preferably in late winter before active growth begins.
Spring flowering shrubs and trees.
Shrubs and trees like lilacs, azaleas, and others will grow best when they are pruned right after they flower in the spring. Avoid pruning them in the winter as it may stunt their growth.
Four to six inches of bark mulch, straw, or shredded leaves - especially when placed around newly planted trees or shrubs - keeps soil temperatures constant and prevents plants from heaving out of the ground due to cycles of freezing and thawing.