From: "Mike LaMana" fake@MikeatHeartwoodConsultingdotnet



Clumps are made by plating 2-4 liners in contact with one another in a
single hole. Usually this is not done with papyrifera. especially in NJ area
because of the species vulnerability to Bronze birch borer and birch leaf
miner. The more common clumper in the trade is Euro. white birch (B. alba)
and its CVs as well as river birch (B. nigra) its CVs.

If I plant the White Birch(s) in Z6, NJ, then I WILL get birch borer?