Cosmos shrub all droopy

TropicalDream

Planted Cosmos from seed late last autumn, it grew nicely but became very leggy this spring. After a few weeks of flowers appearing, the stiff upright stems seem to have lost the will to do so and have become floppy and droopy. Is it due to the lack of watering in the hot weather, or did it need staking? The whole shrubs have become rather messy and unpresentable. 

Also, is Cosmos a perennial and if so when is the best time to transplant it? 

nutcutlet

I think Cosmos is an annual but it's definitely annual in the UK, It  doesn't survive out winters. If foliage is droopy (limp) it's heat and dryness. If it's fallen over it needed staking or pinching out to make it shorter and sturdier