cosmos question

[mothhawk]

How tall do your cosmos grow? This year I raised cosmos "Purity" from seed and planted them out. Most have done well, they are about 3 feet tall and have kept flowering since mid August. There is one plant, however, that obviously thinks it's a sunflower. It is well over 6 feet tall and only now beginning to develop buds. I've had to put a cane support in as they are shallow rooted and the strong autumn winds will tip it over. Is it unusual to have one so tall, or do sports like this often occur? It is in among all the others, so not getting anything different in the way of light or nutrients, but none are in full sun.

[Purple Primrose]

Mine are only about 2ft tall. A 6ft one must be great to look at. If you cloned it, you could have your own cosmos forest.

[Babru]

I grew Dwarf Sensation in a very large trough. Most were about 2 feet tall, but one went up and up, no flowers till much later than the others. Topped out about 5 feet tall. I assumed some other seed had crept into the pack - as happens more often than I'd wish. I just left it to grow, out of interest.

[mothhawk]

Glad to know it's not just mine then, Babru. perhaps not that unusual. If it manages to flower before it gets too cold, I'll try and save some seeds and see if I can grow a tall one next year too.

[Gearoid]

My Purity are about 3ft. As far as I'm aware, cosmos are naturally very tall plants that have been selected over the years to be shorter for gardeners, so it's possible to occasionally have one which retains the original height gene.

[peanut]

Mine tend to be between 4ft and 6ft, various varieties including one that was meant to be dwarf. I don't mind, I love them regardless of their reach to the sky behaviour