horrible black spot - what would you do?
Hi All -
I have been battling black spot on my iris for the past 4 years and I am at my wits end - I do not know WHAT to do.
First off - we have a LOT of bearded iris. We have a 2 acre yard and the entire thing is bordered by about a foot wide bed of iris. It is all in the full beating sun, at the top of a hill (in fact, it borders the yard and on the other side is all downhill rock so it should drain very well), and spaced well, so the fact that we have black spot at all is surprising.
I first noticed black spot about 4 years ago, and have kept up the basics - cutting away affected growth, keeping the beds clear, cleaning the shears between cuttings, etc etc. This spring we started in with fungicide spraying once a week because it has gotten SO out of control - to the point that the iris leaves begin to spot and wilt before it even blooms. At this point in the year, almost every leaf is affected. Nothing seems to be helping - and since the bed is so big it almost seems like I am doomed.
So my question is - What Would You Do? I am tempted to just weed-wack the whole bed down to 6" and then keep it clear from there to see if it helps? I am so upset - I think I am loosing my iris!
Sad note - this is the first year I would say the blooms have been affected. We probably had 50% of the blooms we usually do this spring. I am devastated. Any and all advice would be appreciated!