Other plants, like trees and shrubs, become dormant, or rest in the winter. Tree and shrubs, along with herbaceous (soft-stemmed) plants live for two years or more and are referred to as perennials. They store their food, or sap, in their roots as mentioned above.
While it is a good idea to hold back on water during autumn to allow plants to harden-off for winter, it is essential for shrubs to enter winter with adequate soil moisture. After a few light frosts in fall, irrigate shrubs deeply and apply a layer of mulch to regulate soil moisture and temperature.
Most leaf drop of deciduous trees and shrubs occurs by mid-December. Some plants will start dropping leaves as early as the second week of November while others drop leaves later. But of course, much of that depends on the weather and tree health. If it's unusually cold early, leaf drop is early.
Strong gusts of freezing air can cause the plants' leaves or needles to lose water and eventually turn brown. The water loss can be extreme enough to severely damage or kill a shrub. Creating a temporary windbreak around vulnerable plants will help.
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.
Answer: Newly emerged tree and shrub foliage is susceptible to damage from below freezing temperatures. The new growth on many trees and shrubs can tolerate temperatures in the low 30s and upper 20s. Freeze damage is most likely when temperatures drop into the middle 20s or below.
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.
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.
“Most garden plants are tolerant of a brief freeze period—as long as the roots are still healthy, you'll typically see them recover just fine in the spring,” says Lindsay Pangborn, Gardening Expert at Bloomscape.
Never shear a shrub in fall (or ever, actually, but that's another article) and leave major pruning or renovation for late winter/early spring, or immediately after bloom for spring-flowering shrubs.
(Hint: Watering is mandatory!) Despite the fact your plants are dormant and brown, they should still be watered periodically. Plants that remain dehydrated in winter months often don't survive until spring. Not only does this create extra landscaping costs in warmer months, it can actually damage your plumbing.
With adequate rainfall, established plant species appropriate for our climate typically need little to no supplemental irrigation during the winter. Exceptions to this rule include newly planted trees and shrubs, plants in containers, and periods of unusually dry winter weather.
Use stakes or another support to keep the covering from directly touching the plants. Covering plants helps protect them from a freeze because it helps retain heat radiating from the soil and keeps them warm overnight.
But it's important to know that shrubs do not last forever (even when they're well-cared for). Like other living things, residential plants will eventually begin to die. The average shrub lifespan is typically 10 to 15 years.
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.
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.
When Should You Cover Plants? Cover your plants at night and remove them during the day when the temperatures rise above 32 degrees F, so that the soil can warm up again. Some outdoor plants won't survive the harsh conditions of winter, bring them inside and use these tips for caring for them through winter.
Remember to protect electrical connections from moisture. Cover Plants – Protect plants from all but the hardest freeze (28°F for five hours) by covering them with sheets, towels, blankets, cardboard or a tarp. You can also invert baskets, coolers or any container with a solid bottom over plants.
A brown shrub could still have some live growth and will bounce back with some TLC. Inspect your shrubs for any sign of green growth. If your shrub turned brown because of weather conditions, it can potentially bounce back as the extreme weather subsides.
If the roots cannot pull up any water, the water that transpired from the leaves cannot be replaced; therefore, these cells die causing brown tissue. Once the snow melts, you may observe noticeable differences in shrubs or plants that were partially snow-covered.
Snow that is left sitting on shrubs can make them misshapen and unsightly. And heavy snow or ice on trees can cause limbs to break or also affect the overall aesthetic shape and appearance of the tree.
Once the cold is over, water your plants with an inch of water to help rehydrate and start the healing process. Water is pulled from the cells when it freezes and your plants need water to help recover.
After the freeze, you should be patient. Do not go straight for the pruners and cut everything back. It takes several days for plants to show us just how damaged they are. If plants are mushy and slimy, remove this material to prevent fungal infection or disease in the days to come.