On 23 Jun 2010, at 11:48, Stephen Putman wrote: > I bought a pot of Allium atropurpureum... It has just finished with producing > some seed. I ... noticed that one of the flower stalks was down. Closer > inspection revealed about 17 bazillion ... little bulblets. ...how badly > invasive is this plant? Shall I get it out of the garden fast, or does it > remain more or less in one place with just occasional escapees? Dig the bulbs up and burn them. Carefully lift as many of the bulblets as you can manage, and burn those too. Boil a very large kettle of boiling water and pour it over the area where the bulblets fell. Mark the spot for close attention in future years. If this doesn't work, perhaps you can find a small nuclear device on Ebay. Admittedly your Delaware climate isn't the same as my cool Mediterrean climate in which alliums thrive, but my experiences with alliums proliferating uncontrollably have led me to abolish the entire genus from my garden, the only exceptions being Allium moly, and four locally native species. The difficulty is that commercial strains of alliums are selected for their ease of propagation, and if that includes bulblets in the flower head, underground offsets, and copious seed, so much the better. Methods similar to those in my first paragraph took ten years to eradicate the near-allium Nothoscordum inodorum, and the commercial form of Allium roseum is proving to be equally difficult to eradicate, perhaps moreso. -- Rodger Whitlock Victoria, British Columbia, Canada Maritime Zone 8, a cool Mediterranean climate on beautiful Vancouver Island http://maps.google.ca/maps/…