I leave my allium seed heads because I enjoy the structure even when they're done blooming. Some people spray paint them but I have no problem with brown. I've never had Globemaster reseed but this year I plan to save seeds and wintersow a container. Purple Sensation bloomed after just two years.

I've grown globemaster and purple sensation. I did not cut the heads down last year (my first year for both) becuase I, too, like the structure. However, none of my 3 globemasters came back this year (bummer at $7 a pop) and I definitely lost some of the purple sensation. I'm thinking it may be because I allowed them to go to seed rather than save their energy for blooming the next year. Just my thoughts and experience...

I am sorry to say it is also possible that a critter ate the bulbs.

My original GM bulb has increased to six and I've always allowed them to produce seeds. P.S. increase for me too.

mao

It's my understanding (from Armitage's book) that Globemaster is a sterile hybrid and doesn't produce viable seeds. However the bulbs split in half after flowering, so the clump slowly increases, with each half producing a flower stalk the next year. Purple Sensation will seed around by itself. You can help it along by allowing it to go to seed and sprinkling the seeds in any area you want more plants.

They also like well-drained soil (no winter wet) and a shot of bone meal
after flowering keeps them happy. . .

I always thought Alliums were "critter-proof" because they're members
of the garlic family. . .no?

Carl

Yeah Globemaster is sterile. I just leave them up until they start to look ugly. And I don't know of anything that eats Alliums. If you lost any it was probably due to drainage or some other problem.

I agree, they are critter-proof, and any loss was probably due to poor drainage. Remove the seedheads if you don't like the way they look, or don't want the seedlings (A. 'Purple Sensation') popping up everywhere.

Thanks to everyone for the great advice! I think I will cut the flower stalks off now so that the energy goes to developing the bulbs underground.

Thanks again! :)
Aunt Lou