Re: CULT: toxic Canada thistles?
- Subject: Re: [iris-talk] CULT: toxic Canada thistles?
- From: l*
- Date: Mon, 1 Oct 01 09:02:58 -0600
>Is it not possible that the effect is simply due to robust competition from
>the thistles and shading of the clumps by their vigorous growth?
Yes, it's possible, but I haven't allowed the few thistles in the iris
bed to get large enough to produce any shade, and I also haven't allowed
them to grow abundantly enough within the irises to compete anywhere near
as aggressively as a whole bunch of other weeds (clover, dandelions,
plantain, grasses, etc, etc, etc). None of the other weeds have had this
effect on my irises, but when a Canada thistle comes up in the middle of
an iris clump, all of the iris's top growth starts to die off, and the
rhizomes go into a dormant state. They don't begin to recover and start
new growth until the thistle is killed. This even happens if I keep the
top growth of the thistle pulled or hoed out regularly.
>While many
>plants do produce inhibitors, I don't recall this being said of Canadian
>thistle.
Me neither, but it still seems as though the Canada thistle roots must
contain some deleterious chemical. Of course, it could be that they're
just so aggressive and nutrient-sapping underground that their
competition is a lot more substantial than I realize. Whatever the
reason, Canada thistles and irises do NOT play nicely together in my
garden!
Laurie
-----------------
laurief@paulbunyan.net
http://www.geocities.com/lfandjg/
zone 3b northern MN - clay soil
------------------------ Yahoo! Groups Sponsor ---------------------~-->
FREE COLLEGE MONEY
CLICK HERE to search
600,000 scholarships!
http://us.click.yahoo.com/Pv4pGD/4m7CAA/ySSFAA/2gGylB/TM
---------------------------------------------------------------------~->
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
