Hardly an alpine, I know, but I was wondering if anyone has come across a pest or disease in Yellow flag iris.
Iris Pseudacorus
Iris pseudacorus
The plant was healthy for years and years growing in an old galvanised laundry tub. The last year in that tub it developed the brown streaking in the mature leaves; I build a new pond where the iris was planted last summer. It emerged healthy from winter but the same 'rust' markings showed just before flowering, and since then the plant has declined up to the point as shown in the pictures.
A web search does not immediately show any pests or disease for this iris and it gives the impression that it is quite a trouble maker in many places. Maybe I have a biological control, or is it zinc or tin poisoning from the eroding galvanised tub? would that not leach away in the 3M3 water mass it is in now? Any ideas anyone?
