CULT: Dan's Borers and 'The Received Wisdom'
In a message dated 12/1/98 10:22:55 AM Eastern Standard Time,
<< I try to follow the advice given above. I have seen it often
repeated, and it may probably be true. It's just that with
my experience with the first iris I grew, when I tried
growing it with clean cultivation, no debris, sunniest, best
drained position in the yard it was bothered immediately and
extremely by borers. This same iris when it had grown more
than ten years without cultivation, with mid-day shade, cool
earth, lots of debris never cleaned up, etc. flourished.>>
Yes. I hear you plainly, and I cannot explain it either, beyond noting the
commonplace that every year is different in the garden. Always some 'fresh
hell' as Dorothy Parker termed them...and the delights of course.
May I rave crazily in your direction for a moment, Dan? Consider: maybe when
the old rhizomes become impacted it changes things somehow below the soil line
to make it unhospitable for the borer, or makes it difficult for the borer to
exit into the soil, or results in some buildup of something in the soil. We
hear from time to time that some folks think that irises--and especially
Japanese Irises--may not only deplete the soil but also leach, deposit, exude
or otherwise put something into the soil which, along with overcrowding and so
forth is said to diminish performance. Maybe that is the natural borer control
we haven't been able to otherwise identify. The fact that some
plants--primulas come to mind--exude an allopathic substance that makes it
difficult to impossible to grow them in a place that one of their fellows grew
before is widely accepted.
Of course, your transplanted plant probably differed from the others....
growing all fresh and lush and easily accessible in its nice cultivated new
dirt and looking so succulent, and the rhizomes were not crowded or woody or
wizened...... just thinking aloud here, friend, in lieu of any real
substantial information, but wanting you to know we are all rooting for you.
But I must say that I've seen plenty of 'naturally grown' clumps of irises
riddled with borers, and I know there must be many that are long since gone
that the borer and rot --or their own hypothetical allopathic
<<This first experience makes me skeptical that clean
cultivation discourages borers from bearded irises and
skeptical that bearded irises are best grown all together in
one patch. >>
I like skeptics. It is always best to know what the received wisdom on a
subject is but have enough confidence to acknowledge anomalous situtions since
there may well be something to be learned there. And you won't hear from me
that irises are invariably best grown all together. Any horticultural
monoculture is ripe for problems since diseases and pests can move through
them unhindered and all the plants use up the same stuff in the dirt.
Just give the usual thought to cultural compatibility of soil, sun, root run,
fertilizer and water needs when you select your companion plants and if you
can avoid things that have the same insect pests as your irises--like
aphids--so much the better.
So Dan, please tell us some more about the little historic iris in question.
What does it look like and so forth? We like little historic irises around
here...You been to our HIPS page yet? We invite you to check it out:
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