I have notices my grapevine has some white powdery stuff on top of some of the leafs. Some of the branches have black spots on them as well. Is this due to the amount of ventilation and sun it's receiving or is it something else? What should I do?
Name: Daisy I Reno, Nv (Zone 6b) Not all who wander are lost
First, you should send some photos so we can see what you are seeing. Second, you should let us know where this plant is growing.
Daisy
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and proclaiming...."WOW What a Ride!!" -Mark Frost
President: Orchid Society of Northern Nevada
Webmaster: osnnv.org
Name: Suzanne/Sue Sebastopol, CA (Zone 9a) Sunset Zone 15
It's most likely powdery or downy mildew, the black spots are probably the damage caused by it. Yes, the lack of air circulation can comtribute to the problem.
Some photos and tips http://www.agr.gc.ca/resources...
