Whitewashing fruit trees: protecting the trunk in winter
The white trunk of a fruit tree in winter is not decoration: it protects the bark from winter sunscald. This page explains what that is, which trees are most at risk, when and how to apply the white coating, and the alternative — a trunk wrap. Both sources are US university advisories; they do not agree on everything, and we note where. Traditional lime whitewash works on the same principle — the white colour reflects the sun — but lime washes off faster and may need renewing in late winter. The sources describe white paint, so the details here are about paint.
At a glance
- What it prevents
- Winter sunscald of the bark on the south and southwest side of the trunk.
- Most at risk
- Young trees with thin bark, including fruit trees.
- When
- Late October or November; wraps come off in March–April.
- White paint
- White interior latex paint (not acrylic) mixed with an equal amount of water — on the south and southwest sides of the trunk.
- Wrap
- From the ground to just above the lowest branches; overlap about a third with each turn.
- When to remove
- In March or April, so it does not girdle the trunk or harbour insects.
- How many years
- You may need to do it for several winters until the bark thickens.
- Disagreement
- Universities do not agree on the best method.
What winter sunscald is
In winter the sun can warm the bark on the south and southwest side of the trunk enough that the tissue comes out of dormancy. After sunset the temperature drops and that tissue can freeze, killing a strip of bark.
The damaged bark sinks and changes colour by late spring, then cracks and sloughs off. According to Georgia research on peach trees cited in one source, the southwest side of the trunk can be about 22°C (40°F) warmer than the shaded bark.
It mainly happens from December to March, when the low winter sun heats the trunk and temperatures then drop below freezing.
Which trees are most at risk
Thin-barked species are most at risk, including fruit trees. "Young trees are at greatest risk." The tissue that carries water is damaged, so an affected tree needs extra care, especially watering in dry weather.
Option 1: white paint (whitewash)
- For orchards, the source describes white interior latex paint (not acrylic) mixed with an equal amount of water.
- Apply it to the south and southwest sides of the trunks.
- The white colour reflects sunlight and reduces the heating of the bark.
- The source notes that paint may not be the best choice for young landscape trees.
Option 2: a trunk wrap
- Wrap the trunk with a light-coloured wrap — commercial heavy plastic strips, heavy white paper wrap or a homemade wrap.
- Start at the base and work up to just above the lowest branches; overlap about a third with each turn and secure with tape, keeping it off the bark.
- Best started in November (or late October) and removed in March–April. If a tree is susceptible, a wrap at any time is better than a bare trunk all winter.
- Remove the wrap and tape in time, so they do not girdle the trunk or harbour insects.
Where opinions differ
The sources note that universities do not agree on the best method — for example whether paint suits young trees. So for young, thin-barked trees a wrap is the safer choice according to these sources.
Common questions
Why are fruit tree trunks painted white?
White reflects the sun and reduces the heating of the bark in winter. That protects it from sunscald — damage that happens when bark warmed by the sun freezes after sunset.
When do I do it?
In late October or November. Wraps come off in March–April.
What do I use?
The source describes white interior latex paint (not acrylic) mixed with an equal amount of water, on the south and southwest sides of the trunk. Lime whitewash works the same way but washes off faster and may need renewing in late winter.
Is it suitable for young trees?
Young trees are most at risk of sunscald, but the sources do not agree on paint for young landscape trees — a wrap is the safer choice. Check with local advice too.
Important: This page is general background for a home garden and does not replace an on-site look or a specialist's advice. It names no spray products: for crop protection, always follow the product label and the rules in force.
Related calendars
More seasonal tips
Sources
This page was checked against the public reference below. It is general background, not a diagnosis of a specific plant.
- K-State Research and Extension — Preventing winter sunscald on trees
- Colorado State University — PlantTalk: protecting tree trunks from winter sunscald
Last reviewed:
Want a real answer for your plant?
The causes above are a starting point, not a diagnosis — they don't replace looking at your actual plant. Analyses open soon: register now and your free analyses will be waiting when we launch.