It is not clear to every one whether smearing trees with pitch or grease in order to keep off insects is mischievous or not; some people asserting that such applications are highly dangerous, others that they are highly beneficial. Considering how important it is to settle this point, Mr. Jaeger has recorded in the Monatsbericht fur Pomologie the result of some experiments that he has tried.

A mixture of tar and whale oil was applied to some fruit trees six years old in perfect health, in the spring before they were quite in leaf. 1. A tree, the trunk of which was covered all over by the mixture, pushed feebly; when the tar became firm the bark burst in various places, and began to bleed there. By the autumn the tree was well nigh dead. 2. When the trees had their stems covered only one-third or half-way up, they took very little harm, pushing freely the year afterwards. 3. When only a ring a hand's breadth wide was tarred they took no harm at all. - Botanical Magazine.

Smearing Trees #1

It is not clear to every one whether smearing trees with tar or grease, in order to keep off insects, is mischievous or not; some people asserting that such applications are highly dangerous; others that they are highly beneficial. Considering how important it is to settle this point, Mr. Jaeger has recorded in the Monatsberict fur Pomologie the result of some experiments that he has tried.

A mixture of tar and whale oil was applied to some fruit trees six years old in perfect health, in the spring before they were quite in leaf. I. A tree, the trunk of which was covered all over by the mixture, pushed feebly; when the tar became firm the bark burst in various places, and began to bleed there. By the autumn the tree was well nigh dead. 2 When the trees had their stems covered only one-third or half-way up, they took very little harm, pushing freely the year afterwards. 3. When only a ring a hand's breadth wide was tarred they took no harm at all.

Hence it is to be inferred that a mixture of tar and whale oil may be safe-ly used to form a ring which caterpillars or other insects that crawl up trees from the ground cannot possibly pass. - Botanical Magazine.