EVERGREEN HEALTH • BISMARCK, ND
Evergreen Winter Burn in Bismarck: Why Your Evergreens Turned Brown
Winter burn is brown or bleached foliage on evergreens caused by drying out in winter. Sun and wind pull water out of the needles, but the ground is frozen, so the roots can’t replace it. It usually shows up in late winter and spring, mostly on the south, southwest and windward sides of the plant.
The best fix is prevention: water evergreens deeply until the ground freezes, mulch the roots, and screen the exposed side. If your plant is already brown, don’t cut it yet. Wait until mid-spring and check the buds first.
WHY NEEDLES DRY OUT
What Causes Winter Burn?
The University of Minnesota Extension explains it simply: “Winter sun and wind can result in excessive foliage water loss (desiccation) and because the soil is frozen, plant roots are unable to replace lost water.”
Bismarck winters hand evergreens every one of those problems:
- Frozen ground for months. January lows average around 2°F.
- Wind. Open lots, new subdivisions and homes on the edge of town get the full force of it.
- Dry air and bright sun. Needles keep losing water on sunny winter days.
- A dry fall. A plant that goes into winter short on water has nothing in reserve.
University of Wisconsin horticulturists add that plants with weak or poorly developed roots, like new transplants, are more likely to burn.
MOST VULNERABLE PLANTS
Which Evergreens Get Winter Burn the Most?
Extension services in Minnesota, Wisconsin and Colorado name these as the most likely to burn:
- Arborvitae
- Yew
- Junipers (some types)
- Dwarf Alberta spruce
- Hemlock and fir
- Pine and spruce, especially young or recently planted trees
- Broadleaf evergreens like boxwood and euonymus
Recently planted evergreens are at the most risk. Their roots haven’t spread out yet, so they can’t pull much water even when the ground is soft.
SPOT THE DIFFERENCE
Is It Winter Burn or Something Else?
Brown needles in spring don’t always mean winter burn. NDSU Extension notes that spruce browning in North Dakota often comes from several causes at once, including Valsa canker, spruce bud scale and needlecast disease, on top of drought and a hard winter.
| What you see | Likely cause |
|---|---|
| Browning on the south, southwest or windward side, starting at branch tips and moving inward | Winter burn |
| Pine needles that are half green and half brown | Winter burn |
| Browning worst on the side facing the street or driveway | Deicing salt |
| Older, inner needles brown while the newest growth stays green | Needlecast disease |
| Whole branches dead while the rest of the tree stays green | Valsa canker |
| Twigs clipped or bark chewed near the ground or snow line | Rabbits, voles or deer |
If it’s chewing, see our guide to protecting trees from rabbits and deer in winter. If whole branches keep dying year after year, have a tree pro look at it, since NDSU says disease and insect treatment timing “is critical to be effective.”
RECOVERY • MID-SPRING
What to Do About Winter Burn in Spring
Wait Before You Cut
The most common mistake is grabbing the pruners in March. UMN says to “wait until mid-spring to prune injured foliage and see if buds start to swell.” Wisconsin says to prune dead tissue in mid-spring after new foliage is produced. In Bismarck, where the last frost usually comes around May 12 to 14, that often means late May or June before you know what’s dead.
Check the Buds
Buds are often tougher than the needles around them. UMN notes buds are usually more cold-hardy than the foliage, so a branch with brown needles may still push new growth.
- Pine and spruce: Look at the tips. If the buds are firm and swelling in spring, new growth can fill in, even if some of last year’s needles drop.
- Arborvitae, juniper and yew: Brown foliage on these doesn’t turn green again. Look for new green growth coming from inside the branch.
- Scratch test: Gently scratch a twig with your thumbnail. Green or moist under the bark means it’s alive. Brown and dry means that part is dead.
UMN calls the browning itself “most likely permanent.” The question is whether the buds and twigs underneath survived.
Water and Clean Up
Once the ground thaws, give the plant a deep, slow soak. NDSU says “a long, slow soaking is better than multiple, brief additions of water.” Then cut back only what’s truly dead, back to live wood or a live bud.
If most of the needles are gone, be honest with yourself. NDSU says trees that have lost most of their needles are “likely to not recover no matter what we do.”
FALL PREVENTION • WATER • SCREEN
How to Prevent Winter Burn This Fall
Water Deep Until the Ground Freezes
This is the big one. UMN says to “keep evergreens watered through the growing season and up until the soil freezes.” NDSU’s Extension forester adds that watering conifers late into the fall is important for minimizing winter injury.
- Soak slowly. Aim for water that reaches about 12 inches deep, according to Colorado State University Extension.
- Go wide. Water under the branches and past the outer edge. NDSU notes spruce roots can reach “as far as four or five times the height of the tree.”
- Use a rough rule. CSU suggests about 10 gallons for each inch of trunk diameter per watering. A 2-inch tree gets about 20 gallons.
- Don’t count on your sprinklers. Once your system is blown out in October, use a hose. Our guide on when to blow out your sprinklers in Bismarck covers that timing, and our fall yard checklist puts evergreen watering in order with everything else.
What about winter watering? CSU says to water only when it’s above 40°F, at midday, during long dry spells with no snow cover. In Bismarck, those days are rare in the middle of winter, so most of your watering has to happen before the freeze. A warm, snowless stretch in late fall or early spring is your chance to top up.
Mulch the Root Zone
Wisconsin recommends 2 inches of loose mulch on clay soils and up to 4 inches on sandy soils, spread out to at least the drip line. Mulch helps hold moisture in the soil. Keep it a few inches off the trunk.
Put Up a Burlap Screen
For exposed arborvitae, yews and young evergreens, a screen blocks sun and wind. Wisconsin’s method:
- Drive 4- to 5-foot stakes about 2 feet out from the drip line, mainly on the south and west sides.
- Wrap burlap around the stakes to make a fence.
- Leave the top open.
Don’t wrap burlap tight against the foliage. The point is a windbreak, not a blanket.
Keep Salt Away
Iowa State University Extension says salt damage shows up as “yellowing or browning of the needles and twig dieback,” worst on the side nearest the road. Salt in the soil also makes it harder for roots to take up water, and Wisconsin notes salt exposure makes plants more likely to winter burn.
- Don’t pile salty snow from the driveway on your evergreens.
- Use sand, or a gentler ice melt, near beds. Our snow removal page compares ice melt products for Bismarck temperatures.
- Once the ground thaws, Iowa State says to give salty areas “a thorough soaking” to flush the salt down past the roots.
EXTENSION RESEARCH • SPRAYS
Do Anti-Desiccant Sprays Work?
Maybe, but don’t count on them. The research is mixed:
- UMN: anti-desiccant and anti-transpirant sprays “are not effective means of protecting evergreen foliage.”
- Wisconsin: they’ve “been shown to have limited benefit.”
- Colorado State: applied in October or November, they “may help.”
Water, mulch and screens do more for less money. If you try a spray, follow the label, and still water.
PLAN FOR THE RIGHT PLACE
Planting Evergreens That Hold Up Better
If the same arborvitae burns every spring, the spot may be the problem, not the plant.
- Avoid the hottest, windiest corner for arborvitae and yews, like a bare south or west wall with nothing to block the wind.
- Keep them back from the street and driveway, where salty spray and plowed snow land.
- Plant in spring or early fall so roots have time to grow before the ground freezes.
- Water new evergreens hard their first seasons. Wisconsin suggests up to 2 inches of water a week for new transplants during the growing season, until the soil freezes.
Our landscape installation page covers planting evergreens and windbreaks in Bismarck, and our tree services page covers removing evergreens that won’t come back.
Questions
Evergreen Winter Burn FAQ
Clear answers about browning, recovery, winter watering and prevention.
Concerned about a browning evergreen?
Compare the symptoms above, and speak with a tree professional if branches keep dying. For related topics, see our trees and EAB FAQ.
What is winter burn on evergreens?
Winter burn is brown or bleached foliage caused by drying out in winter. Sun and wind pull water from the needles while the ground is frozen, so the roots can’t replace it. It shows up most on the south, southwest and windward sides.
Will my evergreen turn green again after winter burn?
The brown needles usually won’t turn green again, but the plant may still recover. Buds are often tougher than needles, so pine and spruce can push new growth in spring. Wait until mid-spring and check for swelling buds and new growth.
When should I prune winter burn?
Wait until mid-spring, after new growth starts, so you can see what’s truly dead. In Bismarck, that often means late May or June. Cut dead parts back to live wood or a live bud.
How do I prevent winter burn on arborvitae?
Water deeply until the ground freezes, spread mulch out to the drip line, and put up a burlap screen on the south and west sides with the top left open. Keep salty snow off the plant.
Should I water evergreens in winter?
Only when it’s above 40°F, the ground isn’t frozen and there’s no snow cover, and do it at midday so the water soaks in before night. In Bismarck, most evergreen watering needs to happen in fall, before the ground freezes.
Do anti-desiccant sprays prevent winter burn?
The research is mixed. The University of Minnesota says they are not effective, Wisconsin says they have limited benefit, and Colorado State says they may help if applied in October or November. Watering, mulch and screens work better.
Bismarck Landscape
Not Sure What’s Wrong With Your Evergreen?
If your spruce, pine or arborvitae is browning and you can’t tell if it’s winter burn, salt or disease, we’ll take a look and tell you whether it’s worth saving.
See our other contact options. For more local answers, visit our FAQ.