This section is from the book "The Gardener's Monthly And Horticulturist V21", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
F. B., Brooklyn, New York, writes: "I see you recommend white-washing the stems of fruit trees. I was about to order mine done so, when I happened to read in a standard work on horticulture that it would kill the trees, and there was a long article to show that trees so treated must of a certainty die, because the white-wash stopped up the pores of the bark through which the trees breathed. I have sufficient confidence in the teachings of the Gardener's Monthly to have my trees washed this Winter, but I cannot help calling your attention to the different teachings of science and practice".
[There is no difference between science and practice, but the teacher of science referred to did not happen to know exactly what he was writing about, and this is a very common misfortune. Trees do "breathe" if absorbing the gases of the atmosphere through their dermal tissue can be called "breathing," but this is only when such tissue is young. If we were to cover leaves and the young branches with white-wash, it is likely the trees would suffer. But old branches make a different condition. The tree itself throws old bark off as soon as it can. There is no " breathing " through this old bark, and you may safely help the tree to get rid of it. The work you refer to must be very old. Such statements were frequently met with before the Gardener's Monthly came into existence, and amongst the first sneers at our magazine came some because we showed that the old " Dutch" practice of white-washing trees, was not to be classed with planting under the " signs " of the moon. No good cultivator objects to white-washing the trunks and main branches of trees in these days. - Ed. G. M].