Randy, That's pretty much the conclusion I have come too. I thought I had eliminated them from a bed where I layered newspaper and mulch, but they 'returned' after a couple of years. I must have missed seeing them when they were very small. In another area I have had excellent results by weeding every scrap I can find once each month during a single season. I believe the first weeding takes care of most of the original bulbs strength, the second takes care of the rest, and by the third/fourth weeding there is nothing left to generate bulbs for the next season. This is only really practical where the ground is mostly clear of plants unfortunately... Chad Los Gatos, California -----Original Message----- From: email@example.com [mailto:firstname.lastname@example.org] On Behalf Of Randall P. Linke Sent: Tuesday, February 14, 2012 6:01 PM To: Pacific Bulb Society Subject: Re: [pbs] Chacun a son gout On Tue, Feb 14, 2012 at 4:02 PM, Leo A. Martin <email@example.com> wrote: > Oxalis pes-caprae isn't invasive here in Phoenix...Now O. corniculata is > another story. Both are a pain in my garden in the central Monterey Bay area of California. I covered a few beds which were infested last year with a heavy mulch and the number of plants of both types that came up this year were minimal. I am still pulling them up as they appear and I see them. The O. pest-crapae is now just developing new bulbs, so I am making extra effort to weed it out over the next few weeks. It appears that if you can remove them between the time they exhaust their original bulb and before they can make new ones you have a good chance of controlling it. Randy PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies).