While bright orange or red tree markings might mean a tree is destined for removal, white paint on trees means something entirely different. So, why paint tree trunks white? The roots of this practice stretch back to ancient times, when it was common among Greeks as part of a spring tradition, and also from the belief that limewash could disinfect trees. Today, seeing trees painted white might be less common, but when it’s done correctly, whitewashing a tree trunk can help prevent damage to the tree. White paint on trees offers protection from the sun, harsh weather, and even some pests. Read on to learn more about why people paint the bottom of trees white, why choosing the right paint is key, and how to paint a tree trunk properly.
Reasons for Painting Tree Trunks White
Whitewashing tree trunks can help prevent damage to young saplings and even mature trees. Though it’s not necessary for every tree, it is a time-honored practice in many fruit tree orchards or in areas of the country where the sun is especially intense and there is the most to gain from painting tree trunks white.
To Prevent Sunscald on Young Trees
Like people, plant life is vulnerable to damage from the sun. Painting a young tree trunk white helps reflect sunlight, which prevents the tree’s bark from getting too much sun. Even though a tree may grow well in full sun, it’s more vulnerable to sunscald and other weather effects while young. Saplings have thinner bark than mature trees, and as a result, the bark is more susceptible to the sun’s heat.
In addition, young trees have smaller canopies than adult trees do, so the leaves of a young tree provide the trunk with less natural protection from summer sun and heat than they’ll be able to give when the tree is older. And in winter, a young tree in full sun with no leaves gets heavy doses of the sun’s rays while the sun is lower in the sky. The wood absorbs that heat and then contracts quickly when the sun sets, which can cause damage to the bark. Finally, young trees simply have had less time than sturdier mature trees in your landscape to adapt to sun exposure.
A lesser-known factor is that young trees often face stress from transplanting or environmental changes, which can make them even more susceptible to sunscald. For example, a sapling moved from a shaded nursery to a sunny backyard might struggle to adjust without extra protection like white paint. This small step can give it a fighting chance to establish strong roots.
To Prevent Sunscald on Vulnerable Older Trees
In areas with very hot climates, such as Mexico or the desert Southwest, trees may be prone to sunscald year-round, so people paint the trunks white to protect the south/southwest-facing side. Deciduous trees, which shed their leaves at the end of the season, are particularly vulnerable to sunscald during the winter months or on hot fall days if their leaves drop prematurely. Trees such as birches or aspens, which have thin bark, are more susceptible to sunscald or weather damage.
In addition, some older trees with recent heavy pruning or damage are temporarily more susceptible to sunscald. The scars from broken or pruned branches are weaker than healthy bark, and if a tree was injured or a branch broken by heavy snow or wind, some decay might have already occurred inside the tree. In such cases, it may be best to play it safe and whitewash the trunk of the mature tree to help it through its first winter after injury and prevent further cracks.
It’s worth noting that older trees in urban settings, where reflective surfaces like concrete or glass can amplify sunlight, might also benefit from this practice. The extra heat bouncing off nearby structures can stress even a mature tree, so a quick coat of white paint can act like sunscreen for the trunk.
To Protect Some Trees From the Elements
Much of the reason why people paint tree trunks white comes from orchard owners who want to protect their young fruit trees from winter injury. Some fruit trees, such as citrus trees, have thin bark that’s more susceptible to sun or temperature damage. While all fruit trees have some sort of chilling requirement, sudden thaws and freezes can leave fruit trees and some other types of trees in a vulnerable state. In the winter, an overabundance of sunlight can cause thawing of critical tissues under the bark. They then can refreeze when temperatures drop, leading to trunk cracks and fissures.
These wounds can further weaken a tree and become entry points for pests and diseases. In cases of severe injury, the damage can be fatal. When properly applied, white paint reflects some of the sun’s rays and offsets the effect of extreme temperature swings.
Beyond orchards, this technique can also benefit trees in regions with unpredictable weather patterns. For instance, in areas with warm winter days followed by sharp freezes, the white paint helps stabilize the tree’s internal temperature, reducing the risk of bark splitting. It’s a simple trick that’s been saving trees for generations.
To Deter Pest Infestations
Preventing damage to bark from sunlight and temperature swings also helps reduce the chance that pests or disease can gain access through various small openings in the trunk. These cracks can create entry points for fungi and borers, the larvae of insects such as beetles and moths, which feed on wood and prefer stressed or injured trees. Scale insects and spider mites also look for bark cracks to overwinter and can cause damage or diseases.
In addition, tree trunks painted white can confuse tree-harming wildlife such as deer, mice, or voles, and even farm goats or sheep, especially when the white blends with winter snow. The taste of the paint can also be a deterrent to animals that are prone to chewing bark. To help deter hungry pests, thoroughly cover the bark 18 to 24 inches up from the ground.
Interestingly, some orchardists have observed that white paint can disrupt the scent cues that pests use to locate trees, adding an extra layer of defense. While not a foolproof pest control method, it’s a low-cost way to make your trees less appealing to critters looking for a snack.
How to Properly Paint a Tree Trunk White
Some horticulturists caution against white tree trunk paint on trees less than 2 years old. Other extension offices and tree care professionals encourage whitewashing the trunks of younger trees. All caution that tree trunk painting be done properly to avoid harming a young or damaged tree, and this begins with selecting the right paint and not applying it too thickly. Follow these tips for painting tree trunks white.
- Choose only interior-grade latex paint (avoid oil-based paints), or opt for an organic formula designed for trees.
- Dilute the paint with an equal amount of water.
- Opt for the ideal time for painting bark on trees: the end of fall or in early winter on a sunny day.
- Apply the paint using brushes, sponges, or rags. You can also spray-paint a tree white, but you will likely need to give it two coats.
- Even if you’re using a brush, apply a second coat if the paint seems too thin.
- In most cases, the paint will last a season or two, but reapply each fall as needed until a tree’s bark is thicker or any damage has been repaired.
An alternative to painting a tree trunk is to loosely wrap the tree with a white tree guard in winter. Just be sure to remove the guard in spring to avoid restricting growth. Water young trees regularly, especially during their first year, to keep them healthy. Apply a layer of mulch to the ground around the tree to help retain moisture, regulate temperature, and support any landscaping near the base of the tree.
A practical tip is to check the weather forecast before painting—avoid rainy days, as the paint needs time to dry properly. Also, if you’re painting multiple trees, start with a small test patch on one to ensure the paint adheres well and doesn’t cause unexpected issues. This extra caution can save you headaches down the road.
Additional Considerations for Tree Care
While whitewashing is a great protective measure, it’s not a cure-all. Regular monitoring of your trees for signs of stress, such as discolored bark or unusual leaf drop, is crucial. Combining whitewashing with other care practices—like proper pruning, fertilizing, and pest management—creates a healthier environment for your trees. For fruit trees, consider consulting local agricultural extension services for region-specific advice, as climate and soil conditions can vary widely. In some cases, pairing white paint with organic pest repellents, like neem oil, can boost protection without harming the tree or surrounding ecosystem.
White paint on trees offers protection from the sun, harsh weather, and even some pests. When done correctly, whitewashing a tree trunk can help prevent damage to the tree, ensuring it thrives for years to come. Whether you’re tending a backyard sapling or managing an orchard, this simple practice can make a big difference. Just grab some latex paint, dilute it, and give your trees a little TLC before winter hits.