Your plants should be able to live through a cold snap, but if they're having to endure frigid winters of 25 degrees or less for an extended period, consider wrapping your plants.
Remember, they are an investment and contribute to the overall value and beauty of your home, too. 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.
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.
Shrubs in Ground
If you live in a harsh winter climate, you should do the following: Add 2–3" of mulch, leaves, or pine/fir boughs around the base of the plant. A heavy snow cover will also help insulate and protect the plant through the winter.
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.
How to Protect and Cover Shrubs in Winter. Melinda: Broadleaf evergreens are the most susceptible to winter damage in colder regions like yours. Hemlocks, less hardy and newly planted needled evergreens, and shrubs exposed to drying winds and winter sun also benefit from protection.
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.
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.
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.
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. Cover plants before dark to trap warmer air.
Frostbite and sunscald can be damaging to your shrubs. The primary way that they can cause damage to your shrubs is through the trunk. We recommend wrapping the trunks of your shrubs before the first hard freeze and unwrapping them after the last frost of spring. You can find tree wrap at your local hardware store.
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. Freeze – A freeze is when the air temperature is 32°F or below.
So, keep an eye out for your local weather forecast and get your plant coverings ready when temperatures are forecast to dip to 32 degrees F and below.
Any gardening expert will tell you, (contrary to what you may believe) that pruning encourages new growth just when the plant is trying to go dormant and new growth doesn't have enough time to harden before the first frost and freezing temperatures hit. Pruning at this time of year will severely weaken the plants.
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.
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.
Keeping your plants healthy and happy year round also helps reduce winter damage. Keep in mind that newly planted shrubs and trees might experience more freeze damage than older, healthy plants with a more established root system. Plants in pots are more susceptible to damage than ones planted in the ground.
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.
All tender plants will appreciate being covered when it gets frosty out, even if you live in an area with generally mild winters. Prepare covers for all of your tender plants before freezing winter sets in.
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.
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.
From that experience, I've found the best frost protection for your outdoor plants is either free or cheap. Cardboard boxes and brown grocery sacks make perfect frost cover and at the end of the season can be recycled. I keep various boxes on the patio and when frost is forecast simply put one over the plant.
A covered porch usually provides protection from light frost, but the garage or sun room is better for freezing temperatures. A couple days in darkness won't hurt the plant. Or move them out during the day and back in at night, if cold temperatures persist.
Plastic tarps will transmit cold air to the plants, causing more harm than good. Use cotton blankets or frost cloths for better protection.