The cold snap ends. A week later the Leyland cypress row along the back fence is browning at the tips, worst on the side facing the open field.
That is winter burn. It is not a disease, and the cold does not do the damage directly. It is a water problem: the tree dried out in midwinter, above ground, while its roots sat in cold soil.
Why evergreens dry out in winter
A deciduous tree drops its leaves and waits winter out. An evergreen keeps its needles or leaves, and those keep losing water every bright, windy day. On a mild day that trade is fine. The roots pull up what the top loses.
A North Texas cold snap breaks the trade. A front drops the temperature thirty or forty degrees overnight and brings two or three days of hard northwest wind. The wind strips moisture off the foliage. At the same time cold soil slows the roots to a crawl, and frozen soil locks the water up. The top keeps spending. The bottom cannot pay. The tissue at the far end of the line, the needle tips and outer leaves, dries out and dies.
Two things load the dice. The first is a dry fall: an evergreen that goes into winter already short on water has no reserve. The second is a warm spell right before the front, which wakes the foliage up just in time for the wind to hit it. New plantings take the worst of it, because a root ball the size of a wash tub cannot supply a six foot screen tree the way established roots can.
What winter burn looks like, and what it copies
The pattern gives it away. Browning starts at the tips and works back along the needle. It is worst on the windward side, usually the south and west faces, and on the outer shell. The interior stays green. Damage shows a week or two after the snap, not during it, and a hard winter can add a fresh band of brown after each front.
On broadleaf evergreens like southern magnolia and holly, the same drying scorches leaf edges and tips while the leaf center stays green. On pines, needle tips yellow, then brown, from the tip back. Live oak confuses people every year: it is semi-evergreen here and swaps leaves in late winter, so a thinning, yellowing live oak in February is often just changing clothes, not burning.
Rule out the lookalikes before you settle. Seiridium canker kills one whole Leyland branch at a time and leaves a sunken, resinous patch under it, in any season. Spider mites bronze a screen from the inside out in hot, dry weather, and the white paper test finds them crawling. Bagworms leave their bags hanging on the stripped twigs. Salt damage favors the driveway or pool side and can leave a white crust on the soil. Winter burn sticks to tips, outer foliage, and the windy side, right after a cold, windy snap. When the pattern still will not sort out, our tree diagnosis guide walks the check in order.
The trees that get it here
Privacy screens take the beating. Leyland cypress, arborvitae, and juniper along back fences in Melissa, Celina, and Prosper stand in the open with nothing breaking the northwest wind, and their fine foliage gives that wind a lot to dry. Our privacy screen guide covers which evergreens hold up best here.
Southern magnolia is the broadleaf regular: big leaves, big water loss, edges scorched by late winter in an exposed front yard. Young hollies and newly planted pines burn for the root ball reason above. The common thread is exposure plus young roots. A mature juniper in a sheltered side yard rides out the same front without a mark.
Water and cover before the cold, not after
Prevention is mostly water, applied early. Keep evergreens watered deep through a dry fall and during dry winter spells. Our winter watering guide gives the schedule. When a hard front is forecast, water deep a day or two ahead, while the soil still takes it. Moist soil also holds a little more heat around the roots.
A flat layer of mulch over the root zone, kept off the trunk, slows soil drying and evens out temperature swings. The mulch guide shows the right depth and shape. For a young evergreen in an open spot, a burlap screen staked on posts a foot off the foliage, on the windward side, takes the wind's edge off. Do not wrap the tree in plastic; it cooks on sunny days. Skip late fall fertilizer: the soft growth it pushes burns first. Anti-desiccant sprays get sold hard every fall, but the coating breaks down fast in sun and wind. Small help at best, not a plan.
What to do in spring, and when a tree is done
Do nothing in February. Brown needles never turn green again, but the buds behind them are usually alive, and you cannot see the live line until the tree pushes growth. Pruning early cuts blind and often takes live buds with the dead tips.
Once spring growth shows, prune each burned tip back to green wood with light pruning, water deep through the first dry stretch, and let new growth cover the rest. Most burned evergreens look rough for one spring and ordinary by midsummer.
The done line is plain too. A screen tree that pushes nothing by late spring, browns into the interior year after year, or stands dead on one whole side with cracked bark at the base is not recovering. That tree is a removal and a replant, ideally a tougher species in that exposure. Replanting the same tender screen into the same windy slot just books the same February phone call again.
Common Questions
Will winter burn kill my evergreen?
Tips alone, almost never. Brown needles on the outer, windy side look bad, but the buds behind them usually survive, and spring growth covers the damage. The risk is repetition and depth: an evergreen burned hard two or three winters running, or one that browns into the interior wood, loses ground each year. A tree that pushes no new growth by late spring is the one to worry about.
Should I prune the brown tips off right away?
Wait. In February you cannot see where live wood starts, and cutting early often takes buds that would have pushed. Let the tree leaf out in spring, then prune each tip back to the first green growth. Brown needles never turn green again. On a big screen, one spring cleanup pass beats three winter guesses.
Does watering before a freeze really help an evergreen?
Yes. It is the single most useful thing you can do. An evergreen going into a cold, windy snap with moist soil can keep pulling water to replace what the wind strips from its needles. The same tree going in dry has no reserve, and burn follows. Water deep a day or two before the front arrives, while the ground still takes it, not the night it freezes.
How do I keep winter burn off next year?
Water deep through a dry fall and during dry winter spells, keep a flat layer of mulch over the roots, and put a burlap wind screen on staked posts for young evergreens on the windy side. Skip late fall fertilizer, which pushes soft growth that burns first. If one spot burns every year, plant a tougher species there instead of fighting the exposure.