These are the globe alliums growing around the Finger Rock I recently posted. Though I've had these photos for a couple of weeks, they just kept getting overlooked for posting ... my bad! Anyway, what finally got me moving was this post over at Tales From Far Manor, FARfetched's blog. He has discovered some kind of rogue allium growing on the Manor grounds and wanted some help identifying it and wondered if it was worth keeping or was a potential pest. His specimen is definitely some sort of allium (of which there are some 1250 species in the genus, according to Wikipedia), but since the buds are just beginning to open, it's anyone's guess as to what it will turn into.
Since he says it's over 5 ft tall, for his sake, I'm hoping it's one of the Globe Alliums, and Giganteum would be a nice surprise for him, though I suspect it may turn out to be something a bit less showy. Well, he should know soon enough, but identifying the exact species may be a bit tricky, given the huge numbers of species.
Ours are much more mundane, only reaching about 3-4 feet in height at bloom stage, but they're still very pretty and welcome tenants in the late spring garden, where we have three planted in proximity to Finger Rock. I have no idea what species we have (the blooms on these are not the huge variety, merely about 6 inches in diameter) because they came in a "bargain pack" of allium bulbs that my sister bought a few years ago and she graciously shared a few with us. We're just happy that they're purple!
Alliums are very easy to grow and with time, will produce offsets and multiply. They're also very beneficial plants to have in the garden, because not only do they repel many garden pests (deer and squirrels), they also add sulfur to the soil over time, which is a welcome "side effect" to some plants, especially those susceptible to powdery mildew. We have ours planted right at the edges of our Monarda (Bee Balm) patch because when we first grew it we used to have problems with powdery mildew in the hot summer months. But since the alliums have been there (3 years now), not a hint of that problem. So, if you have any plants with that particular problem, planting some alliums nearby may well solve your dilemma. Besides, they're really striking 'architectural' plants in the border, attracting many bees and other pollinating insects in late May.
In general, we're big fans of most alliums (especially the edible types!), but one example stands out as a 'never want to have near our garden' species is the 'Egyptian Walking Onion' (Allium proliferum) because they are downright thugs! Over the years I've known a few people who actually let them loose in their yard and lived to regret it ... see, these guys "walk" across the area, dropping seeds and bulblets, spreading rapidly in the space of just a few years. When I was in graduate school in Madison, WI, I used to mow a friend's yard once in a while and he had them in abundance in his yard. When you mow over one of them, you really know it! They really get the lacrymal glands going in no time! And if you're brave enough to eat one, you'll have perhaps the most intense onion-y experience of your life! I'm amazed that some people actually like to eat them (that link to Daves Garden had no negatives associated with it!) One of our neighbors across the street has them all over their yard and thankfully, there is a good bit of street and curbs between there and here, because we'd be horrified to see them start showing up in our yard. I guess it's all in the eye and taste buds of the beholder/taster, but I tried them once and they were way too much for me, and I have a very high tolerance for spicy foods and most of the culinary alliums. Caveat emptor is definitely in order for anyone considering letting these loose in their garden ....