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.
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.
Mulch – apply a 2-3” thick layer of shredded bark mulch to the entire root zone of the plant. This offers significant benefits year-round, but is especially welcome in winter for its insulating properties and its ability to conserve moisture even in hard, frozen soil. Water – don't let your plants go to bed thirsty.
Take time to wrap shrubs and small trees with a winter coat of burlap for protection against cold temps. Plants at risk include those with borderline hardiness and evergreens prone to winter burn. Spray evergreens with an anti-transpirant before wrapping in burlap.
In temperate regions, most plants go dormant during the winter. This is the time of year when they've halted active growth and have hunkered down for the cold weather. Because of this dormancy, late winter and early spring are typically the best times to make any adjustments to the shapes of many trees and shrubs.
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.
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.
To protect plants from frost, you will need to cover them to keep the moisture from freezing. While an unexpected frost can leave many gardeners scrambling to find anything to cover their tender plants; it is important to use the right materials.
The easiest way to protect from a freeze is simply by covering plants with a sheet or a blanket. This acts like insulation, keeping warm air from the ground around the plant.
What do you cover plants with in the winter? You can cover your plants in burlap to allow moisture in but keep the harsh elements, like wind, out. Other options include adding 3-4 inches of leaves or a layer of mulch around your plant's base; this will help moderate the soil's temperature.
Cover with a burlap sack: After wrapping a shrub with twine, encase it in a burlap sack or commercial shrub wrap if cold, high winds are a threat. The burlap weave is wide enough that the plant can breathe, but it keeps the worst of the biting wind at bay. This covering also protects the shrub from browsing deer.
DON'T prune during fall.
No matter what type of shrub you have, fall pruning can stimulate late-season growth that may not have enough time to harden. This can weaken and damage the plant—especially if there's an early frost. Instead, wait until winter and trim bushes when the plant is in deep dormancy.
Healthy and adequately hydrated plants have the best chance of surviving winter. Water is often the most limited resource for growth and one that you can supply with relative ease. Water shrubs deeply in fall, especially if moisture has been scarce during the growing season.
The rule on fall pruning is, generally speaking, don't prune in fall. But there are a few trimming tasks you can take on with confidence, provided you approach the job with self-control and a plan. The timing window for these pruning chores is from Thanksgiving to the New Year.
After stems have been removed down to the ground, the shrub quickly begins to regrow. Flowering shrubs produce more blossoms in following years and shrubs with colorful stems, such as dogwoods, tend to grow back brighter and more colorful after rejuvenation pruning.
Don't shear the branches of spring flowering shrubs (Forsythia, Lilac, New Mexico Privet, Spirea, Flowering Quince, and others). These shrubs produce flowers on last year's wood, so removing old growth will reduce or prevent flowering. These plants should be pruned immediately after they are done blooming.
If you want to insulate your plants from the cold, don't use only garbage bags to cover them if they're not made from polyethylene. Use a layer of a blanket, towels, cardboard, or any insulating cloth between the plant and the garbage bag. Don't wrap the garbage bag very tightly where it's touching the leaves.
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.
Cover or wrap vulnerable plants with burlap, old blankets or towels, straw or something else to create insulating air around the plant, such as Harvest Guard's Plant Protection Bag (top right). Remember to tie or weight down your cover material.
If it stays cold for more than one night, can I keep my plants covered, or should I remove the coverings at some point? A. Our recommendation would be to remove the cold protection covering once temperatures are above 32 degrees.
Yes – if you secure the plant properly. Garbage bags work to cover plants and protect from frost, but they must not be allowed to touch the plant's surface. Use stakes and supports to create a tent-like structure over the plant, which will retain warm air. Make sure the trash bag goes all the way to the ground.
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.
You probably already know just how fast shrubs grow and start to look messy. If you wait too long, your shrubs will start to become an eyesore. Pruning less of the plant but more frequently is by far the best for the overall health of it. We recommend every other month, which comes out to be five times per year.