Winter Tree Care: How to Protect Young Trees From Drought, Sunscald, and Salt

Young maple tree with a wrapped trunk and a mulch ring in a snowy front yard. Winter Tree Care

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Good winter tree care matters most for the trees you planted in the last few years. Mature trees with deep roots and thick bark can ride out most winters on their own. Young trees can’t. They dry out, their thin bark splits on sunny days, rabbits chew them down to the wood, and road salt burns their roots, and most of that damage doesn’t show up until spring.

This guide covers which trees need help, the 6 steps of winter tree care, and how to check your trees for damage when winter’s over.

Which Trees Need Winter Protection

Focus your winter tree care on these:

  • Newly planted trees. Colorado State University Extension says newly planted trees are the most likely to get winter drought injury, and that trees generally take one year to get established for each inch of trunk diameter. So a tree that was 2 inches thick when you planted it needs at least 2 years of extra care. Source: Colorado State University Extension — Fall and Winter Watering
  • Thin-barked trees. CSU names linden, maple, ginkgo, crabapple, and redbud as young trees that benefit from a trunk wrap. Trees with thick, corky bark, like bur oak, don’t need it. Source: Colorado State University Extension — Wrapping Trees for Winter
  • Trees near the street or driveway, where they get hit with salt spray and salty runoff.
  • Any young tree in a yard with rabbits.

Winter Tree Care in 6 Steps

Step 1: Water young trees until the ground freezes, and during dry spells

Garden hose slowly watering a young tree on a mild winter day

Dry roots are the biggest winter threat to a young tree. Iowa State University Extension recommends watering regularly until the ground freezes. Source: Iowa State University Extension — Protecting Trees and Shrubs in Winter

After that, keep an eye on the weather. CSU’s winter watering rules:

  • Water only when the air temperature is above 40°F.
  • Water at midday, so it soaks in before it can freeze at night.
  • Water during long dry spells with no snow on the ground, about once or twice a month.
  • Use about 10 gallons of water for each inch of trunk diameter, measured about 6 inches above the ground.
  • Water the root zone under the tree’s branches.

So a young tree with a 2-inch trunk gets about 20 gallons. A garden hose left trickling slowly at the base for a while does the job. Indiana winters are usually wetter than Colorado’s, so you won’t need to do this every month. Save it for a stretch of dry, mild weather with no snow cover. Disconnect and drain the hose when you’re done so it doesn’t freeze to the spigot.

Step 2: Spread a ring of mulch

Mulch holds in moisture and keeps the soil from freezing and thawing over and over. University of Illinois Extension recommends a layer 2 to 4 inches deep and says to keep mulch at least 4 inches away from the trunk. It notes that a ring 3 feet out from the trunk is the maximum for most trees. Never pile mulch against the trunk in a “volcano.” It softens the bark and invites insects and disease. Source: University of Illinois Extension — Proper Mulching Techniques

Our tree mulch ring calculator tells you how many bags you need for your ring.

Step 3: Wrap thin-barked trees to prevent sunscald

Gloved hands wrapping a young tree trunk with tree wrap to prevent sunscald

Sunscald is the long, jagged wound you sometimes see on the trunk of a young maple or crabapple. CSU explains that on sunny winter days, the sun warms the bark enough to wake up the cells underneath. When the temperature drops at night, those cells freeze and die. It almost always shows up on the south or southwest side of the trunk, which is why it’s also called southwest injury. The wound can let in disease and insects.

CSU recommends wrapping young, thin-barked trees for their first 1 to 3 years:

  • Wrap at the end of November.
  • Use a light-colored, crepe paper-style tree wrap that sheds water. CSU says to avoid plastic, dark-colored materials, and burlap.
  • Start at the bottom of the trunk and wrap upward to the first branch, overlapping each pass by about a third.
  • Tape the top, or staple the wrap to itself. Never staple it into the tree.
  • Take it off in early spring, around mid-April. CSU stresses that wrapping is a seasonal treatment, not something to leave on all year.

Once the bark gets thick and furrowed, the tree doesn’t need wrapping anymore.

If you’d rather not wrap, Iowa State University Extension suggests white plastic tree guards instead, and they help protect the trunk from rabbits at the same time. These are rigid white guards, not a soft plastic wrap. Spiral tree guards coil around the trunk on their own and expand as the tree grows. Like a wrap, take them off in spring.

Step 4: Fence out rabbits

When snow covers everything else, rabbits chew the bark at the base of young trees. If they chew all the way around the trunk, the tree can die. Iowa State says a fence of chicken wire or hardware cloth 24 to 36 inches tall is enough in most cases. Pin it to the ground so they can’t dig under, and check it after a heavy snow so they can’t reach over the top on the drifts. Iowa State also notes that white plastic tree guards protect against rabbits and help prevent sunscald at the same time.

Step 5: Keep salt away from the roots

Purdue Extension explains that salt on twigs dries them out, and salt that builds up in the soil can harm roots and break down soil structure. The damage often doesn’t show up for months. Purdue says sodium-based salts are the most likely to hurt plants. Source: Purdue Extension — Deicing Salts Helpful for People but Not Landscape Plants

Iowa State’s advice: don’t pile salty snow around trees and shrubs, shovel before you salt, and use only enough to loosen the ice. Our ice melt calculator shows how little you actually need, and our guide to the best ice melt for concrete, pets, and plants covers which types are easiest on your trees.

Step 6: Handle snow and ice the right way

Heavy snow and ice can bend and break branches. Iowa State says to gently brush snow off small trees with a broom using an upward motion, so you don’t push the branches down. Ice is different. Purdue Extension says not to shake limbs to remove snow or ice, since ice-coated branches are brittle and can snap. Let it melt on its own. Source: Purdue Extension — Dealing with Winter Damage of Trees and Shrubs

If a big limb breaks, especially one near the house or a power line, Purdue recommends hiring a professional. Don’t climb a ladder into an icy tree. For branches that are bent but not broken, Purdue says to be patient. They often go back to their normal shape on their own.

Your shrubs need a lot of the same protection. See our guide on how to protect shrubs in winter.

Winter is also the best time to prune most trees. Here’s when to prune trees, and why oaks can’t wait until spring.

How to Check Your Trees for Winter Damage

The last part of winter tree care is a walk around the yard in early spring. Look for:

  • A long, sunken, or cracked patch of bark on the south or southwest side of the trunk. That’s sunscald.
  • Chewed bark near the ground, which points to rabbits.
  • Brown needle tips on pines and spruces, worse on the side facing the road, which can point to salt spray.
  • Broken or hanging branches.

Iowa State says to heavily water areas where salt built up as soon as the ground thaws in early spring, which flushes the salt down past the roots. Purdue notes that some damaged twigs leaf out and then die back in summer, so wait until late spring to see what really made it before you prune. If you’re not sure what you’re looking at, take a small sample to your county Purdue Extension office.

Winter tree care is one of the tasks on our winter home maintenance checklist.

Winter is a good time to take a hard look at any ash tree in your yard. Bare branches make it easier to spot the signs of emerald ash borer.

Frequently Asked Questions About Winter Tree Care

Should I water my trees in winter?

Young trees, yes, during long dry spells with no snow cover. Water only when it’s above 40°F, at midday, using about 10 gallons for each inch of trunk diameter. Mature trees rarely need it in Indiana.

What is sunscald on trees?

Sunscald is bark damage caused when winter sun warms the trunk during the day and it freezes again at night. It shows up as a long, sunken, or cracked wound, usually on the south or southwest side of young, thin-barked trees.

When should I wrap my trees for winter?

At the end of November. Take the wrap off in early spring, around mid-April. Leaving it on all year can trap moisture against the bark.

Which trees need to be wrapped in winter?

Young trees with thin, smooth bark, like maple, linden, crabapple, redbud, and ginkgo, for their first 1 to 3 years. Trees with thick, rough bark don’t need it.

Should I wrap my trees in burlap?

Not the trunk. Colorado State University Extension says to avoid burlap, plastic, and dark materials on tree trunks. Use a light-colored crepe paper-style tree wrap instead.

How do I protect young trees from rabbits in winter?

Put a ring of chicken wire or hardware cloth 24 to 36 inches tall around the trunk, pinned to the ground, or use a white plastic tree guard. Check it after heavy snow so rabbits can’t reach over it.

Sources & Further Reading