You don’t see sea hollies offered for sale everywhere but like many thistle-y flowers they make long lasting cuts. I bought some commercial cut sea hollies as decorations for a Christmas party and put them into little bouquets with statice. I hung these around here and there and they held just fine for a couple days without being in water at all. The flowers are small and clustered together on a little thimble surrounded by large, spiny bracts. The thimble and bracts are usually blue or gray. I like Patrick Lima’s description of them best when he says they, “seem more mineral than vegetable”.
Eryngium alpinum - "more mineral than vegetable"
I grew Eryngium planum for cut flowers the year after I started Good Scents but almost none of them made it into bouquets. The flowers and bracts were pretty but came in clusters that were too dense to combine easily with anything else. They are odd enough looking that 2 or 3 in a bouquet looks pretty cool but a whole bunch of them look too spiny to be really pretty. After a couple years I dug up all the Eryngium planum plants and threw them out. I hate killing nice plants of any kind but for the business I can't spare the room ofr anything I don't use. The commercial ones I bought at Christmas were Eryngium alpinum which has larger flowers and less dense clusters, so I am going to try starting some from seed this year. If everything works out they will start appearing in bouquets in 2009.
Sea hollies work nicely in a landscape because they are not only drought resistant but (listen up, Barton Hills) deer and rabbit resistant, too. The flowers are held in clusters on fairly long stems so they look better in a group, preferably with something dense in front of them to cover up the gawky stems.