Here’s how it happens:
Sunny winter days: The sun heats up the dark bark of a tree trunk, especially on the south and west sides.
Bark warms up: Cells beneath the bark become active, thinking spring has arrived.
Nighttime freeze: Temperatures plummet—sometimes below freezing overnight.
Sudden contraction: The warm, expanded bark suddenly cools and contracts.
Result? Cracks, splits, and damaged tissue—called sunscald or southwest injury.
This damage:
Weakens the tree
Opens doors for pests and disease
Can even kill young trees over time
And unlike animals, trees can’t move into the shade.
So we help them—by giving them sunscreen.
🎨 Why White Paint? How It Works
White paint acts as a reflective shield, reducing heat absorption from sunlight.
Think of it like this:
Dark bark = black asphalt in the sun → absorbs heat → gets hot
White paint = white roof on a house → reflects light → stays cool
By painting the lower trunk white:
The bark temperature stays more stable
No false “thaw” during the day
Less stress from daily freeze-thaw cycles
Reduced risk of cracking and long-term damage
👉 It’s a low-cost, highly effective way to protect young, thin-barked trees—especially fruit trees like apples, peaches, and plums.
🖌️ What Kind of Paint Do They Use?
Not just any paint!
Arborists use water-based latex paint, usually mixed with water (50/50).
Why?
Breathable — lets the bark exchange gases
Non-toxic — safe for trees and soil
Flexible — won’t peel or trap moisture
Biodegradable — wears off naturally over time
🚫 Never use oil-based or glossy paints—they can suffocate the bark.
Some farmers even use specialized tree whitewash made from lime, but white latex is more common today.
📍 Where You’ll See It
Orchards
Young fruit trees are especially vulnerable to sunscald
Urban plantings
Newly planted street trees get extra protection
Nurseries
Saplings are painted before sale or transplanting
Construction zones
Marks trees to
save
, not cut down (context matters!)
💡 Fun fact: In some areas, white paint means “protect this tree.” In others, it’s purely for sun protection. Always check local codes—markings vary by region.
🎯 Other Tree Markings (What the Colors Mean)
Tree paint is often part of a color code system used by land managers:
White
Protection from sunscald OR marked for preservation
Orange
Scheduled to be cut down
Blue
Surveyor’s mark or utility line area
Purple
Property boundary or no trespassing
Green
Pruning or health treatment needed
Red
Diseased or hazardous tree
Context is key. A white-painted tree might mean "save me" in one forest—and "I need sunscreen" in another.
🛡️ Who Should Use This Trick?
If you have:
Young fruit trees
Thin-barked ornamental trees (like maples or ashes)
Trees recently transplanted
👉 Consider painting their trunks white each fall.
How to Apply It:
Mix equal parts white latex paint and water
Brush it onto the trunk from ground level up to 4–5 feet
Focus on the south and west sides (most sun exposure)
Reapply every 1–2 years as needed
Best time: Late fall, before deep winter sets in.
❤️ Final Thought: Sometimes the Simplest Solutions Are the Wisest
We live in a world of high-tech fixes.
But sometimes, the best answer is humble, quiet, and painted white.
That stripe of paint isn’t flashy.
It doesn’t beep or glow.
But it says something powerful:
“I’m here to protect you.”
Because caring for nature doesn’t always mean grand gestures.
Sometimes, it’s just a brushstroke of kindness—on bark that will grow stronger because of it.
