What kind of paint do you use on tree trunks?

Interior white latex paint, diluted one part paint to one part water. Two rules matter. Use water-based latex, never oil-based, because oil-based paint damages bark. And use interior rather than exterior latex, because some exterior paints contain antimicrobial additives that can hurt the tree. Do not use anything labeled as a sealer, primer, or wound paint.

When should you paint a tree trunk white?

Late fall, before the first hard freeze, so the coating is in place through the winter. Sunscald is a December-through-March problem, not a summer one. Paint the trunk from the soil line up to the lowest branches, and concentrate on the south and southwest faces, which take the afternoon sun.

How many years do you need to protect a young tree?

Two to three winters after planting for most trees, per Utah State Extension. Once the bark thickens and starts to furrow, the tree protects itself. Thin, dark-barked species like cherry and peach can stay susceptible well past that, so keep an eye on them.

Is painting the trunk better than wrapping it?

For a backyard tree, wrapping usually looks better and works just as well. Colorado State Extension calls latex paint an orchard and nursery method rather than the preferred home landscape option. Paint wins on cost and durability if you have twenty fruit trees. For the single maple in your front yard, use a light-colored crepe-paper wrap from late November to mid-April.

Why Are Tree Trunks Painted White? (And Should You Do It)

Q: Why are tree trunks painted white?

To prevent sunscald, also called southwest winter injury. On a cold, sunny winter day the dark bark on the south and southwest side of a trunk absorbs heat and wakes the cambium underneath. When the sun drops behind a fence or a cloud, that tissue freezes and dies, and the bark splits the following spring. White paint reflects the sunlight so the bark never warms up in the first place.

Tree trunks are painted white to stop sunscald, a winter bark injury that kills the living tissue on the southwest side of young trunks and splits the bark open the following spring. The white coating reflects afternoon sun so the bark never warms up enough to start the problem. It is an orchard trick that works, and it looks exactly as odd as you think it does.

If you have driven past an orchard in the Central Valley in January and wondered why half the trees look like they are wearing white socks, that is the answer. Nobody is decorating.

Here is when it actually matters, what to use, and why I would not do it to the maple in my front yard.

What sunscald actually is

The name is misleading. Sunscald is a cold-weather injury, not a summer one.

On a clear winter day, dark bark absorbs sunlight and heats up. Utah State Extension puts a number on it that surprised me the first time I read it: the south side of a tree can be as much as 77 degrees warmer than the north side on a cold winter day. That warmth wakes up the cambium, the thin layer of living tissue just under the bark.

Then the sun drops behind a fence, a building, or a cloud. The bark temperature crashes back to ambient in minutes, and the tissue that just woke up freezes and dies.

You will not see anything in December. You see it in April, when a long vertical strip of bark on the southwest face turns sunken and dark, then cracks and peels away. That is why it is also called southwest winter injury. The damage lands where the afternoon sun hits hardest.

Frost cracks are the related version: a vertical split that opens with a sound like a rifle shot on a cold night. Same underlying cause, same side of the tree.

Which trees need it

Not all of them, and this is where most advice goes vague. Utah State Extension names the susceptible species directly: apple, ash, aspen, birch, cherry, cottonwood, crabapple, honeylocust, linden, maple, mountain-ash, oak, peach, tuliptree, and willow.

Colorado State Extension adds ginkgo and redbud to the wrap list, and makes the opposite point just as usefully: thick-barked trees like bur oak do not need it at all.

Two things drive the risk:

Age. Young trees with thin, smooth bark are the vulnerable ones. Once bark thickens and furrows, it insulates the cambium on its own.

Bark color and texture. Thin, dark bark absorbs the most heat. Cherry and peach hold onto smooth dark bark well into maturity, so they stay at risk longer than a maple does.

A newly planted dwarf peach tree is close to a worst case: young, thin-barked, dark, and often planted in the open with nothing shading the trunk.

Where you live decides this

Sunscald needs cold nights and bright winter afternoons. That combination is a Colorado, Utah, Minnesota, and Michigan problem far more than a coastal California one.

I garden in zone 9 in the Sacramento Valley. Our winter lows rarely sit low enough for long enough to freeze warmed cambium, and our winter afternoons are as often gray and foggy as they are bright. I have never painted a trunk here and I have never lost bark to sunscald.

Where I would take it seriously:

Anywhere with hard freezes and clear winter skies, so most of the Intermountain West and the northern tier
Open, exposed sites with no fence, building, or evergreen shading the trunk
South and west-facing slopes
Trees planted where reflected light off a south-facing white wall doubles the exposure

If you are in USDA zones 8 through 10 west of the mountains, put your winter effort into frost protection for tender trees instead. That is the real risk in a mild-winter climate.

How to paint a trunk properly

Three details matter, and getting any of them wrong is worse than doing nothing.

Use interior white latex paint. Some exterior latex paints carry antimicrobial additives that can damage bark. Interior latex does not.

Use water-based, never oil-based. Colorado State Extension is blunt about this: oil-based paint damages trees. This is the mistake that turns a preventive measure into an injury.

Dilute it one part paint to one part water. You want a thin reflective coating that lets the bark breathe and expand, not a plastic skin. Some sources go as thin as one part paint to two parts water, which is fine. Straight undiluted paint is not.

Brush it on from the soil line up to the lowest branches. Cover the south and southwest faces at minimum; wrapping the full circumference is easier and does no harm. Apply in late fall, before the first hard freeze.

One coat lasts a couple of seasons, which is the practical reason orchards use paint instead of wrap. When you have four hundred trees, you are not rewrapping every one of them each November.

Wrap is usually the better home option

For most homeowners with one or two young trees, skip the paint.

Colorado State Extension calls latex paint an option “often used in nurseries and orchards” but explicitly not the preferred method for home landscapes. Their guidance for a yard tree:

Use a light-colored crepe-paper tree wrap. It has enough give to expand with the trunk and it sheds water.
Do not use plastic, dark-colored material, or burlap. Plastic traps moisture against the bark, dark material defeats the entire purpose by absorbing heat, and burlap holds water.
Wrap at the end of November and remove it in mid-April. This is the part people skip. Wrap left on year-round traps moisture, hides borer damage, and can girdle the trunk as it grows.
Only for the first one to three years after planting. Utah State Extension says a minimum of two to three winters. Somewhere in that range is right for most trees.

A roll of tree wrap costs a few dollars and covers several young trees. Our tree wraps and trunk guards guide compares the materials in more detail, and the broader tree trunk protection guide covers mower damage and rodent chewing, which are the other two reasons to put something around a trunk.

The trade-off: paint is cheaper per tree, lasts longer, and never needs removing. Wrap looks better in a front yard and comes off in spring. If you have an orchard, paint. If you have a specimen maple by the driveway, wrap.

The other reasons people paint trunks

Sunscald is the main one, but not the only thing going on when you see a white trunk.

Rodent and borer visibility. A white trunk makes gnawing damage and borer entry holes obvious from a distance. Some growers use it partly as an inspection aid. The paint itself is not a pesticide, and treating it as borer control is a mistake. If you have boring insects, you need an actual treatment.

Orchard convention. Commercial stone-fruit growers whitewash almost reflexively, because peach and cherry are both high-risk and a lost tree is lost income for years. The habit spreads to home orchards by imitation.

Decoration and roadside marking. In much of India, Latin America, and southern Europe, painted trunks along roads are a visibility and tradition thing, not a horticultural one. If you have traveled and wondered, that is a different practice that happens to look the same.

What to do instead if the tree is already damaged

If the bark has already split and peeled on the southwest face, painting it now does nothing. The tissue is dead.

Do not seal the wound. Do not paint over it. Wound dressings trap moisture and slow the tree’s own compartmentalization. Cut away only the loose, clearly dead bark so water does not pool behind it, and leave the edges alone.

Then keep the tree from being stressed while it walls the damage off: consistent water, mulch out to the drip line but not against the trunk, and no fertilizer push. Our guide to tree rot and decay covers what happens when a trunk wound does get colonized, and leaf scorch covers the summer version of environmental damage that people often confuse with disease.

A young tree with a strip of sunscald damage on one side usually survives. It just carries the scar, and that scar is a permanent entry point worth watching.

The short version

Paint trunks white to prevent sunscald, in a cold climate, on young or thin-barked trees, with interior white latex cut 1:1 with water, applied in late fall.

In a mild-winter climate, or on a mature thick-barked tree, skip it. And for a single tree in a visible spot, a crepe-paper wrap from late November to mid-April does the same job without making your front yard look like a nursery row.