Whitewash trees

[LeeR]

This may be more of a historical question than anything else. I have noticed (most often in the rural parts of the southern U.S.) that trees in driveways and property boundaries have their trunks whitewashed to a height of about six feet or so. What is the function of this?

My wife suggests that it might be some time of preventative for pests or disease. I was thinking it might have (in the past) helped prevent people from driving into trees at night.

Does anyone have a definitive answer for this?

Thanks,
Lee Rickerson
[email protected]

 

[BostonBull]

Aesthetics?

 

[sawsong]

to mark the property boundary more positively in lieu of any fence or boundary stones?

 

[underwor]

In some northern areas, it is done with the idea that it will reflect the sun in winter and keep the side of the tree from heating up and suffering "sunscald" as it refreezes quickly at sundown. Don't know how successful it is, but I also saw it in Russia when I visited there. It kind of makes sense for real smooth barked trees.

 

[Bermie]

It used to be done over here on citrus trees, which have very thin bark. I have not seen it done for a very long time now.

I have also seen it done in Portugal, since a lot of our agricultural and landscaping workers come from the Azores, perhaps it was brought here with them, a cultural thing?

 

[Ekka]

Prevent sun scald on thin bark trees.

On radical orchard pruning they sometimes apply it too.

Although this page is not yet complete there's a blurb on it

http://www.weareallabouttrees.com.au/pruning.html

On a recent fence line prune of a mature mango the limbs were scalded and cankered where they were opened up to direct sunlight for the first time ... we were removing the new growth but frankly, the entire limb was stuffed.

 

[BayouTree]

I think it's a cultural thing that has been passed down. People think it will keep the "bugs" out of their trees, and when someone else sees it done they want to "protect" their trees too. I don't see it as frequently here as I used to, but it seems pretty common in Mexico ( I guess going back to that cultural thing). Bark beetles seek out dark vertical objects, so maybe they would have trouble percieving a "light" vertical object and they might be less likely to chew through paint. I don't imagine it could be very effective though.

 

[DGG]

I have also seen it on military bases. I always figured it was a make work job for the poor chain-gang newbie types to impress the big cheeses, wardens, colonels, etc..

 

[kapow2826]

Aesthetics?

In Fresno Cal.Walnut and Fig trees are white washed to prevent sun scald. This also helped to make the Carpenter worm borer gallery openings easer to see.

 

[BlueRidgeMark]

It used to be done a lot in southern California. It's thought to keep bugs out of the trees. I suspect it's an old wive's tale.

 

[Ed Roland]

In some northern areas, it is done with the idea that it will reflect the sun in winter and keep the side of the tree from heating up and suffering "sunscald" as it refreezes quickly at sundown. Don't know how successful it is, but I also saw it in Russia when I visited there. It kind of makes sense for real smooth barked trees.

Would the benefits outway the detriment of having a sealed barrier over that portion of the lenticils? Just curious.

 

[treeseer]

what are the ingredients of whitewash? CaCO3? sounds like a trunk drench of an essential micronutrients. Indians in california used to grind up oyster shells and make a paste to put on trees. I see a lot of sunscald and I think it makes a lot of sense for all the other reasons above too. re lenticels, i think gas will exchange through whitewash but less through latex/oil paint.

 

[kevinj]

In Michigan, it's usually just a white latex paint to prevent sunscald.
And mostly on fruit producing trees.

 

[kapow2826]

I think it's a cultural thing that has been passed down. People think it will keep the "bugs" out of their trees, and when someone else sees it done they want to "protect" their trees too. I don't see it as frequently here as I used to, but it seems pretty common in Mexico ( I guess going back to that cultural thing). Bark beetles seek out dark vertical objects, so maybe they would have trouble percieving a "light" vertical object and they might be less likely to chew through paint. I don't imagine it could be very effective though.

Would the benefits outway the detriment of having a sealed barrier over that portion of the lenticils? Just curious.

kapow 2826 I have worked in both white washed Fig and Walnut orchards. I did not see any problems.

 

[kapow2826]

I Am A Retired Insect Pathologist And Worked On White Washed Fig And Walnut Trees In Early 1980. My Concern Was The Commercial Development Of A Beneficial Insect Parasitic Nematode For The Control Of Carpenter Worm Tree Borers. The White Wash Was Applied By The Grower And Not Part Of My Reseach. The Grower Applied Latex On The Fig And Hydrated Lime On The Walnut. The Latex Trees Had Borer Galleries On The Trunk And Major Limbs. The Hydrated Lime Treatment Had The Majority Of The Galleries On The Major Limbs Instead Of The Trunk. One Additional Advantage To The Lime Application Is That It Also White Washed The Ground Under The Tree Canopy. The Contrast With The Fresh Redish Brown Frass Droppings Makes It Easier To See For Determining Active Borer Infestation. The Nematodes Worked And They Are Commercially Available Internationally.
I Recall, It Looks Like Hydrated Lime Has Potential. You Might Contact Your Local Farm Advisor. Kapow2826

 

[cobbler]

Security?

I often thought that the white tree trunks gave you a better view of someone sneaking around at night. In the days before street lights the bad guys would show up when they crossed in front of a white tree. Sort of like how a deer will show up nice when they cross a white birch stand. In the same vein folks in the south used to sweep their yards so that they could follow the track of a snake that came near their house in the night. Cobbler

 

[kapow2826]

Cobbler You made my day. I remember my Dad saying His job was (as a kid to sweep the dirt in the front yard. I guess lawns were not popular in Fresno Ca. in 1904.

 

[MadelineG]

I Am A Retired Insect Pathologist And Worked On White Washed Fig And Walnut Trees In Early 1980. My Concern Was The Commercial Development Of A Beneficial Insect Parasitic Nematode For The Control Of Carpenter Worm Tree Borers. The White Wash Was Applied By The Grower And Not Part Of My Reseach. The Grower Applied Latex On The Fig And Hydrated Lime On The Walnut. The Latex Trees Had Borer Galleries On The Trunk And Major Limbs. The Hydrated Lime Treatment Had The Majority Of The Galleries On The Major Limbs Instead Of The Trunk. One Additional Advantage To The Lime Application Is That It Also White Washed The Ground Under The Tree Canopy. The Contrast With The Fresh Redish Brown Frass Droppings Makes It Easier To See For Determining Active Borer Infestation. The Nematodes Worked And They Are Commercially Available Internationally.
I Recall, It Looks Like Hydrated Lime Has Potential. You Might Contact Your Local Farm Advisor. Kapow2826

Hi. Do you know if there is a way you could contact me? I am writing an informal article about white washing trees and I would love to quote you as an "expert". Thanks!

 

[treeseer]

It has been reported that native americans in california made a paste from oyster shells to put on oaks. Nowadays, calcium is applied to combat sudden oak death.

:jawdrop:

 

[Husky137]

Hi. Do you know if there is a way you could contact me? I am writing an informal article about white washing trees and I would love to quote you as an "expert". Thanks!

An expert who capitalizes every word?