How to paint trunks to protect trees from sunburn, sunscald
Q. I just planted a fruit tree and was told by a friend that I should paint the trunk with white paint. I really don’t like the idea of a tree painted with white paint in my front yard. Is it really necessary to paint young trees?
A. The short answer is yes, it’s important to paint or wrap your tree to prevent sunburn and sunscald on the trunk and scaffold branches.
Winter sunscald occurs during late winter, when sun-exposed bark is heated during warm days, then frozen during the night. The warming wakes bark cells from dormancy, leaving them susceptible to injury and death from cold. When this happens repeatedly, the bark dies and sloughs off, exposing the wood underneath.
Sunburn causes the same type of damage that sunscald does, but happens during Redding’s hot summer months. Bark is sunburnt if the young trees don’t have enough branches or leaf canopy to shade the branches or trunk.
Trees may also sunburn if they become water stressed, especially during the heat of the day.
Young trees with thin and dark bark, including ornamental and fruit trees, are most susceptible.
Trees that have damage to their bark are unable to move nutrients within the damaged area and may have portions of the trunk, or even entire branches die. Severe damage can cause the entire side of the tree to die.
Trees with damaged bark also provide an attractive place for tree boring insects to lay eggs, causing further damage to the tree.
The number one cause of damage to the trunk or limbs of the trees in our area is winter sunscald or summer sunburn.
To prevent sunscald, orchardists recommend that you wrap trees with white tree wrap or muslin, or paint the tree trunk and any exposed branches.
You don’t have to use white paint on your tree. There are plant guard paints that come in grey, green or brown colors. These paints can be more expensive, but they blend with the tree trunk better. Plant guard paints can also protect against boring insects and rodents, such as voles, chewing on the trunks.
For a more inexpensive solution you can try a milk paint. There is one in the color: Tree Bark. Milk paints may need to be applied more often than other types of paint, but they are very safe for the environment.
What your friend was most likely referring to was painting the tree with a 1:1 mixture of water and water-based indoor latex paint. This is what I use to paint the tree trunk and branches. If you use latex paint, it’s best to choose a light reflective color such as white.
One should never use acrylic or oil-based paint, which could harm or even kill the tree. By protecting the trunks of young trees you’re insuring that your tree will grow strong and healthy for many years to come.
The Shasta Master Gardeners Program can be reached by phone at 530-242-2219 or emailmastergardener@shastacollege.edu. The gardener office is staffed by volunteers trained by the University of California to answer gardeners' questions using information based on scientific research.