"JohnS" expounded:


These plants can get like the weeds. They drop many many seeds and tubers is
deep, not so easy to remove them all. We can not dig them all out so this
year I will use Roundup on them. They took over iris bed. After years they
get to be tall ugly plants with red flowers.

Depending on your climate only. They are in no way weedy up here.
--
Ann, gardening in Zone 6a
South of Boston, Massachusetts
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