Re: California poppies & root rot
- Subject: Re: California poppies & root rot
- From: M* &* L* D*
- Date: Thu, 23 May 2002 05:46:41 -0700
Another possibility for root rot besides that caused by Phytophthora is
Rhizoctonia root and crown rot. I don't think it's easy to tell them apart.
However, Phytophthora really likes it wet (for example, plants sitting in
standing water), whereas Rhizoctonia likes it wet but just moderately wet
(but still excessive). I think if you have a root rot problem and you really
don't think it was that wet, then it's probably Rhizoctonia and not
Phytophthora.
Two years ago I had a flower bed with Vincas that had plants collapsing with
wilting. I think it was due to Rhizoctonia. I was giving the plants a good
soak but the soil had good drainage and it really wasn't that much water (no
puddling or standing water). Once I cut back on the water, then the problem
disappeared.
Both Rhizoctonia and Phytophthora have a very wide host range and could
attack almost any plant in a garden.
To complicate things, if the soil is too wet, then the plant can have
problems from lack of oxygen. I have heard debates between plant
physiologists (who think lack of oxygen for the roots is causing the
symptoms) and plant pathologists (who think that pathogens like Phytophthora
are causing the symptoms). Probably both factors are involved.
--Mark
