In article , "Anna Merchant"
wrote:

Isn't Oxalis a weed ? Or are there many differing types of oxalis, and only
one is a weed ?

I grow several oxalises & some are aggressie & others are very delicate.
"Iron Cross" is not notably invasive but becomes quite an enormous clump
with huge pink flowers. I also have a tender oxalis called O. siliquosa
"Velvet Sunset" which has bright orange & yellow leaves just as flowery as
the flowers themselves, which are bright-bright pink. It spreads nicely
but not invasively. I've the evergreen form of our own Northwest native O.
oregana, which is a bulbous variety that spreads rather slowly even
though hardy as the dickens. I've something called Chilean Wood Sorrel
(O. adenophylla) that hardly even looks like oxalis the leaves are so
strangely folded; it's at some risk of dying out of the garden in wet
winters as it likes to be dry when dormant, but if located in extremely
well-draining soil, should naturalize without becoming invasive. But I
also have Oxalis corniculata var. atropurpurea, a purple-leafed sorrel,
extremely pretty, but highly invasive. I never planted that one, it just
always lived here, but since a certain number of weeds in the garden are
inevitable, this is a good one as weeds go.

By & large it is unfair to the many restrained species & varieties of
sorrel to blame all of them for the weedy behavior of O. corniculata &
some few others that once established are never gonna go away.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/