I've got Globemaster and another really tall one that my MIL gave me bulbs for but didn't know the variety. The foliage dies back on them both. This was a great year to test their standability. We've had a LOT of wind, and not a one of them went over. I've got them spaced pretty far apart, and have obedient plant (yeah, I know) that gets tall and takes their place once they've died back. I've had mine two or three years, and I don't see that they've increased any, but MIL says the ones she gave me will. They look just like Globemaster, but are quite a bit taller, and have somewhat smaller globes.

I have two kinds - I think they're Globemaster and Gladiator. One tops out at about 3' tall and the other blooms shorter and a bit later in the season. Their upright habit does not appear to be at all affected by wind or rain.

On both, the foliage dies back fairly rapidly after bloom and they stay dormant until the following spring. Mine have increased more rapidly than I would have expected and I would estimate that several have doubled over one growing season. Or maybe I've just forgotten how many I planted!

I can't find anything negative to say about the ornamental onions except that the bulbs are expensive. Totally worth it in my view, though.

In my old garden, I also grew a little one called I think a. azureum which bloomed very late in the onion season, but was a nice shade of blue. In my current garden, I was a sucker and ordered some a. roseum as freebies from a catalog I normally avoid. These are not worth the space they take up.

Thanks, Leslie! I bet Gladiator is the one my MIL gave me. What is your soil like? Mine is pretty heavy-I've wondered if that's why they're not multiplying for me. My MIL is on sandy ground, and she's got a ton of them.
Brenda

When do you remove seedheads on Purple Sensation? The seeds formed very soon on mine. If removed them immediately I'd have enjoyed the flowers only for a very short time. I did not do it and now look at green globes standing outside my window. I've read this will reduce the number of bulbs for the next year. Is this true for you? I also wonder if I should dig and store them until fall? I'm done with most of my tulips but have not touched the alliums.

I'm glad to hear no one has problems with them toppling over in our springs storms.

Anna beth, that's a good point about cutting off the seed heads. I read something about that a long time ago, but forgot until you mentioned it. I better snip the heads off mine. Maybe save them for a dried arrangement.

Leslies and flowerluvr, thanks for the positive input about globemaster and gladiator. I think I'll try a small grouping of 3-5 of each and see if I like the look.

The foliage of Alliums often dies back just as they begin to bloom. If you don't remove the seedheads, those green seedpods will open up and they will eventually drop their black seeds and then you will have them reseeding in your garden. It will take a couple years until they become large enough to bloom, but they will pop up all over the place. The bulbs also split and increase the number of alliums that will come up in future years. There is no need to dig them up now or ever, unless you want to move, or divide, them. They are pretty sturdy growers, and storms usually don't bother them.

Anna beth, don't dig them up. They're OK to stay in the ground all year.

flowerluvr, my soil is red Virginia clay partly amended with horse manure. I would guess that my allium bulbs are pretty much in clay, way down there where I buried them!

Don't worry about deadheading 'Purple Sensation' if you want more of them. Or make that UNTIL you DON'T want more of them. Dang things seed like crazy. The seedlings will look like wimpy little blades of grass, so don't get too wild with the weeding next spring. In about three years you will have a knockout display of 'Purple Sensation' if you didn't deadhead.

As for the bigger ones, Allium christophii is doing okay in spite of no deadheading for me, and one of the other big ones ('Giganteum'? 'Gladiator'?) returned without any decrease in size. A. sphaerocephalon also seeds nicely if left to its own devices, but be sure you plant it in full sun or it gets too floppy.

I'm not seeing seedlings from my other Alliums yet, but I really don't expect to see any increase for another couple years.

I grow A. Globemaster, cristophii, Gladiator, Purple Sensation, aflatunense, spherocephalon, schubertii and molly.

Gladiator multiplied for me, but petered out after 5 years. The stem of this one snaps after a heavy rain. No other Alliums do that in my garden.

Globemaster also multiplies, but the flower head gets smaller every year. I like this one for its long bloom time. It has secondary florettes, that's why. The stem is very sturdy.

I like schubertii too. Pricy, so I planted only 5 last year and 5 the year before. Only one showed up this year. I crammed too much in one spot, so they have no room to grow.

The most favorite of mine is cristophii/christophii/albopilosum:
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I leave the seedheads alone until the wind blows them away in late fall. I actually leave all of the Allium seedheads until they breakway by themselves. I have heavy soil and I mulch heavily. I get a lot of seedlings but they never grow enough to bloom for me, because I mulch thickly every spring and fall.

May I ask why A. roseum "not worth the space they take up."? I don't have this one yet, but the photos look great. It's not a big ball of color, but looks charming. Anyone else growing it?

I never met an allium I didn't like, although A. bulgaricum is my favorite:
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It slowly increases, so after about 5 years I've got about twice what I started with.

I also really like A. moly, A. sphaerocephalon, and A. azureum (aka A. caeruleum) for its unusual true blue flowers.

I'd have said my favorite is Society Garlic, but it's not a true allium anyway, it's a close relative in the amaryllis family, Tulbaghia violacea. Sure smells like an allium.

About a. roseum: I wasn't expecting a big ball of color, but I was expecting a little ball that was at least visible. To me, the flowers on this one always look past their peak, even when they've just opened, and the color is pretty washed out. It's possible they'd do better in some shade.