When is Late Winter? Late winter is 4 to 6 weeks before spring thaw begins. This could be any time in January to May, depending on your climate. Use your average last frost date and count back.
Late winter is a good time to prune most plants. Because plants and their pests are dormant this time of year, pruning cuts can be made without the risk of pests and pathogens entering the tree through the wound.
In fact, it is better to prune a little at a time than to make drastic cuts. For plants that shed their leaves (deciduous plants), the best time for winter pruning is from the beginning of November to the end of February. To prune evergreens you can start later, from mid-December, and continue until February.
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.
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.
"As soon as trees and shrubs go into dormancy, pruning can begin," he said. "And you can prune up to the time when buds begin to plump up." From mid-November to mid-March, you can shape and thin your deciduous plants in preparation for the spring season ahead.
Generally, the best time to prune or trim trees and shrubs is during the winter months. From November through March, most trees are dormant which makes it the ideal time for the following reasons: Trees are less susceptible to insects or disease.
Most plants prefer a temperature of no less than 60° F, though many can tolerate as low as 40° F. Along with this, while the improper temperature can certainly be an issue, fluctuations in temperature are the true killer. Learn the ideal temperatures for your green friends so they can be healthier and happier.
The general rule of thumb is that most plants freeze when temperatures remain at 28°F for five hours. Of course, there are exceptions to this rule. Seedlings, with their tender new leaves, often give up the ghost when temperatures dip to 32-33°F. Tropical plants have differing low-temperature thresholds.
Freeze Warning - This is issued when there is at least an 80% chance that the temperature will hit 32 degrees Fahrenheit or lower. Light freeze - 29° to 32° Fahrenheit will kill tender plants.
Winter is usually the best time.
Without the leaves, you can easily see the branching structure of the shrub and decide what to cut. Dormant pruning is usually done in late winter, six to 10 weeks before the average last frost in your area.
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.
Municipalities and homeowners often remove the lower limbs for pedestrian and vehicular clearance or to let the sun shine in for grass to grow. Mature trees, especially evergreens, benefit when healthy lower branches are left intact. Removing large limbs can increase the risk of decay.
If you want to prune in fall, wait until trees drop their leaves and are dormant—usually October or November. After leaf drop, you can see the tree's structure and identify disease and insect problems more easily.
According to gardening expert Mike McGrath, author of Mike McGrath's Book of Compost, and radio host of the show You Bet Your Garden, the rule of pruning is that you should NOT prune in fall. That's right, nothing and no exceptions.
Many commonly butchered shrubs and trees bloom in spring. This means that they've already formed their flower buds. So if you go crazy with the loppers and wail away on a spring-bloomer during the fall, you just might cut off the flower buds and that means no spring blooms.
Most potted or hanging plants, like petunias, are fine as long temperatures don't dip below 39 degrees, and especially if the temperature doesn't dip to the freezing mark.
Frost becomes more widespread when the temperature falls below 32°F with some freeze possible. A hard freeze is possible when temperatures fall below 28°F.
So even though the weather forecaster isn't predicting a freeze, once temperatures start to drop below 40°F you need to be aware. Once temperatures drop below 40°F, you may want to start covering your plants with a frost blanket depending on what you're growing, which we'll get into in just a bit.
The easiest way to harden transplants is to place them outside in a shaded, protected spot on warm days, bringing them in at night. Each day, increase the amount of sunlight the transplants receive. Don't put tender seedlings outdoors on windy days or when temperatures are below 45° F.
Some plants can survive outside even when temperatures hit freezing. Others need to be brought indoors when temperatures reach the mid-40s. Be sure you know this before you plant.
As gardeners, our frost dates are based on 32 degrees Fahrenheit (0 degrees Celsius) to avoid the risk of any plant death. However, know that even if air temperatures are as high as 38°F, frosts may occur on the ground and on plants. It's better to protect plants just in case!
Avoid pruning in fall.
Pruning cuts can stimulate new growth that, unfortunately, will be killed as temperatures drop to freezing. Trees and shrubs reduce their energy production as the growing season ends, so new growth in autumn will use a plant's stored energy reserves.
As a general rule, prune spring-blooming trees immediately after they flower. Prune trees that bloom in the summer or fall in late winter or early spring before the end of their dormancy. Routine pruning of dead or dying branches can be done at any time.
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.