So, does anybody have a definitive answer as to why all the tree trunks get painted white?

Failing that, I suppose I'll accept wild speculation and failed attempts at humor from Chingis.

i've heard a few theories but the most plausible are that it's insecticide or that the white paint is to make them more visible at night and therefore help drivers not to hit them, especially when reversing. i'd go with the former if i had to choose but i personally feel that it's often down to habit.

by the way, does anyone know why they feel the need to cover anything else within a meter radius with with that white paint? i've seen grass, shrubs, concrete, fenceposts and even a few bicycles splattered with that stuff.

My wife, who is a long time Kunming native, tells me it's an insecticide.

The spatter around the area is likely caused by inattentive painters who don't really give a damn what else they hit. I've seen the same from guys watering road side plants from those big truck and soaking anything else that was in close proximity including electric bicycles and people.

They do this all over china, including the splatters, drips and spills.

I asked a friend, a botanist that worked at Kunming Botanical Institute, why is was done. She said she didn't know. Maybe it is insecticide but she didn't think so. But, says she, her specialty is mushrooms.

It's KIND of an insecticide - but more designed to keep ants at bay. Ants are actually a useful pest, but their symbiotic partners - aphids - are a nuisance pest. As for the 1 meter radius - just your typical lazy unskilled laborer with no job pride or satisfaction.

It's always been a msytery to me too, but last week I asked an English speaking lady whose large business does "city-based horticulutre" in Kunming and elsewhere. As others have said, she confirmed it was a form of insecticide, but widely acknowledged to be pointless and unnecessary, expecially in cities. However, she pointed out that it provided cheap employment for unskilled labour and "some things in China are more troublesome to stop than to allow to continue". Indeed. Wise words!