As the post title suggests it is for reducing sun and pest damage.
Some trees can be damaged by the sun in cold climates in the winter…the sun heats up the bark which causes it to expand or lose dormancy, then when the sun goes down it cools rapidly to the ambient temp which causes cell death. This ultimately leads to wounds on the tree and potential death of the tree.
painting the trunk white causes the sun to reflect and reduces the heat absorption by the trunk, thus preventing the thaw/freeze cycle that causes the damage.
1 Like
-
So this is only for winter? What month should I start painting the trunks of my trees? September/October?
-
I know that my grapevine and pomegranate have lost some of their bark down at the base. Will that doom them down the line?
-
How come if it’s so important, it’s not talked about much if at all. I’ve never encountered a YouTube video discussing it, and this is the first post I came across on this topic. You would thing something so important would be more talked about, at least on YouTube.
1 Like
Yeah! 
Glad to know I’m not missing anything.
So far as I know, painting trunks is customary in the fall (or every other fall). Snow reflects the sun in the early spring and can heat tree trunks above freezing. Extremely cold nights cause the trunks to freeze again, causing tissue damage, which looks like split bark. White paint reflects the snow-light and reduces the thawing and subsequent refreezing.
I think it’s only important for some trees in some climates. Not like you need to rush out and paint every tree or vine you have 
I only learned about it in my research over the years on pawpaws. If you spend much time at all reading about them, you’ll definitely hear about painting trunks.
Kind of pricey but here is the OMRI listed solution to latex paint: Introducing new Eco-Orchard Paint! – milkpaint
It’s what I am now using.
2 Likes
Santa Rosa, Elephant Heart and Satsuma plums as well as apricots seem like prime candidates here in S. NY to paint. They often suffer cambium damage sometimes dying as a result. Other times they can be stunted by it.
The only thing that stops me from doing it in my nursery is fear of how my customers will react to painted trees- that and the time.
2 Likes
Before the summer heat arrives just a reminder some trees trunks readily sunburn.
Blake…how has the eco-orchard milk paint worked for you? Are you planning to use it again this winter? I’ve been looking for some information on it, but the MSDS on their site has a link to the wrong product.
It works well. However it also degrades faster than latex paint and lasts one season. However, latex paint only lasts about one season as well. They both work about the same in my experience, so it boils down to whether you are OK using latex paint or you want a more organic option. Either way most fruit trees benefit in multiple important ways from seasonal painting with white paint.
1 Like
Just a related anecdote about reflectivity and heat adsorption . Some years back I got a used propane tank for the new greenhouse. It was painted silver. Propane guy checked it out and filled it, then a few weeks later on some hot, sunny days I noticed the release valve venting a bit of propane. I called the propane shop and they said paint your tank white. I did, and it solved the problem. The difference in reflectivity between pure white and silver (which is white with a bit of black mixed in) was dramatic.
As this relates to tree trunks, if you live in a very sunny area where sun scald is a potential problem, probably worthwhile to use white paint to be safest. Other light colors will work to an extent, but white really will do the best in keeping the heat out.
1 Like
Welp, we’ll see how it works. 1/2 gallon interior latex, and about a pint of castor oil. I was going to do 2:1 but then I read the castor oil label which recommended something like 6 oz per gallon… I used maybe half of my quantity for 24 smallish fig trees, some single trunk some multi.
2 Likes
Painted about 1/2 my trees today. I lost so many trees to rabbits last winter that this was essential.
2 Likes
Painting the tree trunk doesn’t stop rabbits. I paint the tree trunk every year and the rabbit still chewed trunk every year.
1 Like
Hmm, IV organics claims that rabbits are stopped by their paint. They claim that castor oil in their paint makes the bark inedible. I guess I’ll have to protect with chicken wire also.
1 Like
Is there reason people rather paint than put on protection like 6x6mm wire mesh cage for rabbits and mice and then a stick/ bamboo stem fence for sun protection? We have used butter acid for mouse and rabbit in the past maybe of interest to add to paint for some of you as it can be cheap and stiiiinky.
I understand the metal should last 30 years or more if it is well made (galvanized 0.7mm thick 6x6mm mesh cut into 50cm pieces) $1.30 per tree
The bamboo or make your own out of basket willow stems, i purchased a grass cane fence and cut it into 20-30cm pieces. should last 3-5 years or more. $1 per tree
I also use plastic tubes for starting some trees, but see the issue with plastic breaking down, heat accumulation in the tubes and limited lifespan compared to these where replacing the woody sun protection is the main thing.
I should take a close up but here is a far off example of the tree protection.
1 Like
Painting is not done for that reason as much as to prevent sunburn only. Where the sun is hot in our area, it can sunburn and kill small trees.
That is what i put on the bamboo for. I had a few older trees bark tear from winter sun burn. I have not seen a summer sun issue before but it would also do better than paint i imagine because it is a loose airy separation from the sun. Or am i missing something… @clarkinks
1 Like
Bamboo should work if it’s long enough pieces. My pears have very few rodent problems. Graft them over later after the rodents have learned their lessons. The rootstocks have wicked thorns.
Sometimes the trunks on my pears are not perfectly straight. Look closely at the picture from above
I use full sized rootstocks, making it hard for deer to steal my pears
2 Likes
I make my “solar fences” about 3 feet tall. what is the max typical height you think is needed? I understand if the sun can’t heat up the base the sap won’t flow to a higher hotter part of bark… but maybe the sap in the bark higher up still can activate? I understood it comes from the roots. Curious to understand it better cuz it sucks to have a old tree split it’s trunk bark.
Planting in N-S rows I understand also helps shade the trunks or having the first scaffolding branch on the south side of the tree.
3 feet should be good. The fence should be even with the foliage. Even if you white wash the trunks, it helps. Think this thread will help you understand my strategy Full Size Pear Tree Regret . Pear tree trunks develop very thick bark, unlike apples and other fruit trees. The rodents can not damage mature trees. The one in the photo is 30 feet tall.
Pear trees that produce bushels of fruit and avoid disease
1 Like