Hello Steve in scorching Delaware, Something sounds amiss with your "Allium atropurpureum". > 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? Allium atropurpureum is a member of the Melanocrommyum section of Allium (think of the big ball type, Allium giganteum, A. 'Globe Master', A. hollandicum 'Purple Sensation', etc.). Allium atropurpureum comes from parts of Europe, to Turkey, to Siberia, and is related to Allium nigrum and the true A. cyrillii (not A. cyrillii as most often distributed in Hort). All alliums in this section take 5-6 years to flower from seed. When the seed falls, a winter cold period is required before germination. They are NOT bulbiliferous species that produce bulbils in the flower head which can sprout as soon as they hit the soil. My guess is, you do not have the true A. atropurpureum, but have a weedy imposter instead, because to me it seems highly unlikely that there would be any sprouting bulblets at all from that species. I'm not that far from Delaware, being in Massachusetts, and I find this species slow and actually difficult to keep going (and yes, it is blazing hot here these days too;-). Do you have any photos of your plant that you can share? If you don't have a place to upload them, forward some to me and I can post them on my website and supply links to further this conversation and plant ID. Here's what mine looks like, photo taken 05-30-2010: The stem is about 3' tall. http://plantbuzz.com/misc/… here's what the seed pod looks like, taken today, not ripe yet, there are no bulbils, never seen bulbils nor proliferating bulblets on this species: http://plantbuzz.com/misc/… Regarding invasive alliums, sure there are a few bad ones that can proliferate too much, but given a genus of nearly 1000 species, don't let a few bad ones completely put you off this fun, ornamental, and most worthy genus, there are many excellent species. Be cautious of advice from alliumphobes who have abolished the entire genus because of a couple poor Allium choices. I recommend taking a broader view of plant invasiveness versus weediness. I grow hundreds upon hundreds of different Allium, and can honestly say, my Allium garden has not gotten out of control, there are no uncontrollable thugs... I was careful to avoid a few known weedy types, although still working on getting rid of A. tuberosum, a thug which seeds about too enthusiastically. However, there are whole parts of my yard, my woods, my lawn, forever taken over by and lost to Campanula takesimana, one of the most beautiful yet horrible weeds out there. Campanula punctata was nearly as bad, but can't withstand drought, and I finally eradicated it after about 10 years trying. But C. takesimana is taking over my property, and escaping to the neighboring woods and street edges. Do I shun the entire genus Campanula because of these two most horrible of horrible thugs? No, surely there are good Campanula species too. On a positive note, there's a chance that Campanula takesimana might prove to be an effective competitor and control against poison ivy ;-) Here are some links to Campanula takesimana taken on my property today: http://plantbuzz.com/misc/… http://plantbuzz.com/misc/… http://plantbuzz.com/misc/… http://plantbuzz.com/misc/… http://plantbuzz.com/misc/… Don't be fooled by the pretty looks of this siren beauty, many nurseries carry it and many named color forms; avoid it like the plague. Mark McDonough Massachusetts, USA, near the New Hampshire border, USDA Zone 5 antennaria@charter.net http://www.plantbuzz.com/
