View Full Version : Why are tree bottoms painted white?

06-01-2002, 07:34 AM
Telephone poles too. You know what I mean, the bottom portion of the trunk or pole is painted solid white, up to about hip or waist level. I thought it might be for reflective purposes, but a friend thought maybe for pest control. So--anyone know for sure?

06-01-2002, 07:43 AM
To reflect car headlights ?

Stupendous man
06-01-2002, 07:57 AM
I have seen trees painted with a special coating that prevents catterpillars from crawing up to the leaves..

06-01-2002, 11:43 AM
It's to protect against rot. In Arizona, the bottom of orange trees are painted white because of flood irrigation: the trees will be in standing water all day. I've never seen telephone poles here painted like that, but if you're in a area that gets a lot of snow or other moisture, it would make sense.

06-01-2002, 12:43 PM
For telephone poles, I would generally think it is strictly for visibility.

For trees, it can be several things:
- visibility
- insect repellent (one white, sticky product prevents ants and other crawling critters away from fruits; a separate white product reduces the opportunity for borers to get into the tree)
- anti-windburn (this would appear only on smaller trees with undeveloped bark in areas where there are frequently high (or steady) winds during the cold months)

Since borers prey on live trees and the telephone and power line fruits are generally inedible, I would not expect to find insect repellent on those poles. Termites might be an issue, but those poles are saturated with anti-rot products that would, I would think, make them fairly hostile to termites (and borers), anyway.

06-01-2002, 01:35 PM
I had only seen this done in Latin America, and never got a straight answer as to why. The most common response is that it had something to do with insect repellent. One day in Venezuela we noticed same guys painting the trees in a plaza, and the four intelligent, knowledgable people I was with four different answers. So I walked up to the guys and asked them, and they said it was to make the trees look nice. In other words, they were too embarrassed to admitt they had no idea. The most reliable answer I ever got was that it was to protect against insects, but that it was a stupid practice because the paint harmed the tree more than the insects.

06-01-2002, 02:37 PM
So many choices!

Thanks for all the info guys, I guess me and my friend were both right.


06-01-2002, 02:57 PM
I believe folks who paint their trees and rocks are those who remember fondly their time in the military. The only effective bug stuff I'm aware of that you paint on a tree is Tanglefoot for insects. It's a gooey stuff you put on the trunk, and it keeps ants from carrying aphids up into the tree. You make a band a few inches wide around the tree, and it's not white. Really, really nasty stuff to deal with.

06-01-2002, 05:58 PM
I used to work with an old gentleman who had been in the landscape industry since just after WWII. According to him, it originally was done to prevent sun scald since the white paint reflected the sunlight*. Same reason people use paper tree wrap now on young trees. Anyway, he also said that a lot of people back in the day simply did it because they saw their neighbors do it and thought it was the fashionable thing to do. So a whole lot of trees got painted for no real reason at all.

*I'm not saying it worked, just that he maintained that was the reason they were doing it.

06-01-2002, 06:45 PM
I asked this question some months ago, and now it is in that group
of threads that went "POOF". Here in Brazil this is a habitual
thing. Can't be because of traffic, because I have seen LOT'S
of cars smashed into phone polls and trees that were painted white
(didn't seem to help THEM any way) I have personally gone to eat
guavas from a tree that was painted white and the fruit was infested with
Black Bee maggots, and the tree itself had a whole road of ants
trucking right up the trunk over the paint - I have also seen
high rise buildings with rooftop gardens that had this white tree
base thing - as ugly and un-natural as ever - where there were
no real bugs and no traffic either. as I recall the best responses

1) In municipal areas (parks and what not) It gives consistency.
Nice green lawns, well manicured bushes, nice white tree trunks.

2) On roads, see #1, and to help with the visibility issue, as in,
this black area is the road, all these white posts ARE NOT.

3) Because we have ALWAYS done this. The "Prefectura" (Mayor) pays
scads of electric orange clad workers to do SOMETHING, and
when they are not extorting money from citizens at Christmas time
(see tipping thread) they can be seen splashing white paint on
almost ANY stationary object from the waist down.

4) HI dead horse!:rolleyes:

06-01-2002, 07:29 PM
Anyone who is inclined to drive off of roads in their car is going to hit the tree weither it is painted or not so I expect it's not for them. Mind you, since when did anyone ever think twice before doing anything ever. They probably are there to say to people "this tree is here, please try not to hit it when you decide to completely veer onto the pavement".

06-02-2002, 05:03 AM
Well around here we put the plastic around the trunk of a tree to prevent rabbits from eating the bark during the winter. A rabbit will sometimes skirt a whole tree during the winter killing it off. My guess is paint would make it much less appetizing and have the same effect.

That being said that doesn't explain telephone poles. Several years back NYSEG wrapped all the poles along their local high power line with heavy, small squares, wire mesh up to a height of about three feet. I've heard it explained (I've got nothing to back that up) that skunks (IIRC, it was a while back) were chewing on the bottom of the poles because the chemical they were treated with (do they still use creasote ?) tasted good to them.

My guess would be a variety of reasons and pests.

Bosda Di'Chi of Tricor
06-02-2002, 05:40 AM
Originally posted by Janx

4) HI dead horse!:rolleyes:

I wish to point out that, at least some of the time, OpalCat smells better than this.


See, Opal? I'm sticking up for you! :D

06-02-2002, 02:46 PM
- - - Because they can't reach the tops.

06-02-2002, 05:38 PM
I'd assumed that the whitewash on trees was done for visibility as I've only ever seen in on trees right next to the road.

Insect repellent paint is (as others have already mentioned) very sticky; a variant of this is the greaseband - a broad paper strip coated with a sticky compound, usually (in the UK) applied to apple trees to prevent Winter Moths from crawling up the trunk (the female is wingless).

06-02-2002, 09:01 PM
I emailed a citrus grower in Phoenix and this is what they wrote me:
The trunks are painted white to protect the bark from the ultraviolet rays. Citrus bark is very thin, and if exposed to the sun, the bark burns, peels back from the inner cambien layer, which is the transport for nutrients from the root system to the foliage. The inner cambien layer keeps the tree alive. If people let the trees grow naturally, i.e., with the branches growing to the ground, this white paint routine wouldn't be necessary. Plus, the best citrus fruit is harvested from these lower branches, as it's cooler there and more protected from the sun and heat. Trees in groves are growing to the ground. Hope this helps with your message board group. Thanks for the email.
Aha! :cool:

06-03-2002, 06:41 AM
Interesting. I've only seen this phenomenon in Romania, where it's certainly not done to thin-barked citrus trees. Like other people in this thread, I was unable to get any reliable response. The best I can figure is that it's done for visibility purposes, as I generally see them painted white only on the sides of the road. If you've ever driven at night in Romania, then you'd know how much of a help it actually is. However, I'm not completely satisfied with this explanation, as I've occassionally seen the odd tree nowhere near a road with the trunk painted white. Perhaps somebody thought it looked nice and decided to paint their own trees white. I don't know.

The explanation about insect repellant and preventing sun-scalding, though, doesn't impress me either. At least not for the trees in Romania. The trees that were painted didn't seem any different than the trees that weren't painted. All the trees looked fairly healthy, producing fruit, regardless of the condition of their trunks.

06-03-2002, 07:11 AM
I recall my grandmother white washing her trees, and this was in the 40's and 50's in western Kentucky. Everyone did it, and as a child, i just accepted that adults did weird things and never asked why. I assume because it made the yard look a little tidier.

06-03-2002, 07:50 AM
I've only seen it done to citrus trees in Arizona--no one in my home state of Pennsylvania seems to do it. How puzzling, and how eye-opening to me to find that it's done all over the place!

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