Question
QUESTION: This is the second season for my yellow smoke bush in full sun till late afternoon.  It tripled in size this season and all of a sudden the leaves in the middle of the plant began turning color, drying up and dying.  It looks like it is dying from the inside branches out. Could this be verticillium wilt? If it is, can it spread to my other shrubs/trees (maple?)
Thank you for any information you can give me.

ANSWER: Hello Dianne

Thank you for your question.

Smoke Bush (Cotinus) is affected by verticillum wilt.  The only way to be sure your plant is infected is to remove a strip of the bark from an affected stem.  An indication of verticillium being present is brown or purple/brown streaks along the length of the stem.

Verticillum wilt is caused by a fungus, which is found in the soil, in plant debris (fallen leaves, dead twigs, etc.), and in the plant itself.

There is no effective control, unfortunately.  It will eventually kill its host - it may take a few years or it could happen over a single growing season.

The only thing you can do is remove the infected plant completely, together with the soil near the roots, as soon as you identify the problem.  

This infection is wide ranging and can be harbored in other shrubs and even garden weeds, and can be spread on the garden tools you use on an infected plant, so after every use of a tool be sure to thoroughly clean it, using  garden disinfectant.

Your maple is also known to be vulnerable to this infection along with sumach, lime, berberis, daphnes, quince, apples and pears.

Keep an eye on your maple and do not plant a new Cotinus in the same area.

I do hope you are able to contain this problem.

---------- FOLLOW-UP ----------

QUESTION: You indicated that sumach is also vunerable to this disease.  I have 3 Tiger Eye Sumac trees that were planted this past spring.  Are they the same as "sumach"?

Answer
Hello Dianne

Yes I'm afraid that Sumac and Sumach are the same thing, just a difference in spelling.

If you have planted you new Tiger Eyes well away from the Cotinus that is affected and you remove it and the soil in the vicinity of its roots as described yesterday, they may well be alright.

If, on the other hand they are quite near the Cotinus, it may be possible to move them if they are still small, though this may risk spreading the infection - I'm afraid this has to be your call!