Rot and borer resistant iris: a myth?

Carolyn asked:

 >> What are your cultural practises that rot and borer is such a
 >> devistating problem??

They're not problems of any kind in my garden, so far.  I'm only growing a few
varieties of TB, and that only for two seasons. But Jim Wilson said that
depending on where you garden, losses are inevitable without spraying,
regardless of cultivar.  As an organic gardener falling in love with bearded
iris, I don't want to believe that, but at my level of experience, or lacking
more resistant cultivar suggestions from this group, I can't just flatly
disagree.  The 'search for Cygon' thread makes it sound as if a lot of you
depend on it.

It's good to hear that cultural practices can reduce the problems to a
tolerable level. Any practices in particular to recommend besides what I'm
already doing: removing old leaves promptly, regular resetting, and providing
well-drained fertile soil and good siting (air circulation, sun)?

 >> How about starting a breeding program with hardy historics...?
 >> How about looking at the breeding that is in the cultivars that are
 >> Duykes winners and other winners and see what is in their parentage
 >> and figure out whether hardiness and resistance to rot is a factor?

I'm a HIPS member, and 90% of my iris order list for this season are pre-1940s
cultivars.  With thousands and thousands of bearded iris in commerce, I have no
intention of hybridizing; thought that might have come across fairly clearly in
a previous message.  I'm hoping to select from what's out there.  I've
downloaded the index to the LIST archives from Tom's web site in an effort to
catch up on the discussion Linda's referring to (but now that planting season
is here, very much hope I don't have to plow through the whole two months'
worth to find it).

Not sure how at my level of knowledge I could tell anything at all about
hardiness and resistance to rot by looking at a pedigree chart. Frankly, I'd
rather figure this out by talking to people who've grown lots of iris.  A
number of list members who might have some thoughts on this issue are already
heading off to the convention, so I'll stay quiet and read the archives until
after next week. Your poll on cultivars that stand up by themselves is most
welcome, so maybe you'll want to give that a post-convention 'push', too.

Re: hemerocallis -- The breeding-induced problems and weaknesses Munson was
warning against with daylilies are much more serious than simple lack of
hardiness in the north; they include rot of established clumps and increased
susceptibility to insect pests previously unheard of with hems. You're
certainly right about newer iris being refreshingly inexpensive compared with
the madness in the daylily world, but I'm sticking with the older cultivars in
any case. (Though I wait with open ears to hear how Clarence's LADY BIRD
JOHNSON does for anyone; what a stunner.)

 Nell Lancaster, Lexington, VA   75500.2521@compuserve.com    USDA zone 6b
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index