I've grown it for several years and love it. Mine are the 'Queen' series (rose) and they get really tall, at least 5'. Usually around mid July or so I'll start deadheading. I don't do them all at once. When you deadhead, they'll get more side branches. They really get nice and full that way. Btw, they reseed like crazy, but just turn the soil over the next Spring and most will be gone. You'll still find some that pop up here and there, but if you don't want them, then just pull them out.
Enjoy!

Kat

I never deadhead cleome.....the first bloom just gets longer and longer with little fleurettes and those wing like seeds all along the stem, and it still gets the side branches. Sometimes I will cut off all the seed pods along the stem....just to keep down the reseeding.
Linda C