Question
Hi,

I just bought a chokecherry and it has this black stuff growing around a branch.  It feels like a cork and I was wondering if this is going to take over the tree and kill it or can I do something.  I just bought this tree a week ago.

Thank you

Cheryl Orr

Answer
What it sounds like is a disease called Black Knot of cherry. If left unchecked it will kill the plant. The control starts with prunning the infected branch and destroying the branch. Here are two web links that will discribe the disease and controls. http://web.aces.uiuc.edu/vista/pdf_pubs/809.pdf

http://www.msue.msu.edu/vanburen/e1330.htm

I did leave something out--Since you bought the treee a short time ago I would strongly suggest you return the plant to the nursery and ask for a disease free replacement. Most nurseries have a 30 day return policy.