This section is from the book "The Gardener's Monthly And Horticulturist V20", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
I notice with considerable interest a communication on page 83, of the Monthly, in reference to the bad effects of the use of linseed oil on Pear trees, and also notice that the editor is disposed to attribute the trouble to"adulterated oils".
Now I have most thoroughly tested this subject, with precisely the same results as E. 1. B., and can further advise that when blight sets in after the trees have been well oiled, the death of the entire tree is bound to follow. My last year's experience was very discouraging. Usually, with me, when a tree has become seized with blight, I can arrest its progress by trimming out the diseased parts, which still does very well if the tree has not been oiled; but when it has, no care or attention will save it, and even a slight attack means certain death.
My orchard is planted on a southern slope, well drained, and the trees carefully looked after. But the destroyer still comes, and this last Summer it took Manning's Elizabeth, Clapp's Favorite, Flemish Beauty, Buffum, St. Ghislain, Madelaine, and others, and those I have remaining look black and ugly. Some of the trees have been done two years.
I feel quite certain the oil is pure, as it came from the most reliable druggist I know of, Robt. Shoemaker & Co. I am now experimenting with oil on Marechal Neil Rose, but can tell better later on.
[This is valuable testimony, and seems to put a solution of the enigma further away than ever. The success of the Mississippi trees under oil is undoubted; and several hundred apple and pears on the grounds of the editor of the Gardener's Monthly were painted with linseed oil from top to bottom, with the very reverse of injurious effects. We have offered our explanation why other people's died, which does not seem wholly satisfactory. We will now ask why these cases should have been so successful. - Ed].