It may be to shady or you may be over fertilizing them. Al

Beth, normally you can't keep cosmos from flowering and speading all over the flower garden. I have even had them come up in pots in my pond and still flower.

Sounds like too much Nitrogen. Perhaps you could try superphosphate 0-20-0 or another fertilizer with a lower nitrogen number. What fertlizer do you use?

I think I probably over-fertilized my cosmos. As I said the plant grew like crazy, it just didn't flower at all.

Beth

I simply tried a different variety this year. My first experience last year was very much like yours...I had blooms, and they were pretty, but they were so monstrous! I swore off them until I found:

Sensation Mix
Cosmic Series
Summer Bride

All dwarf varieties that I'll be trying this year.

Hmmm... Unless there's more than one cosmos called sensation mix then it's hardly dwarf. Mine was 6 feet tall.

julie- Mine specifically says Dwarf Sensation mix on the packet...brand was Hart's I think. Hold and I'll try to find a pic. 18-24" on these pinks/whites:

Here' tis:

{{gwi:6945}}

Oh, ok. I was gonna say you could always try pinching them which I never did with mine. I also over-fertilized so I won't be doing that this year.