or am I too late?

Cosmos and Zinnias come in various sizes, colors and forms. Bachelor's button is a very fast grower. How about nasturtiums? They come in climbing and bush varieties. If you are looking for more foliage type plants, you might look into the veggies. There are some lovely lettuces. If you want height, what about corn? Some of the ornamentals are great. And it isn't too late to try lots of the annual vines like morning glories or scarlet runner beans.

I'm looking for tall "cut-flower" types like zinnias.

You can still plant zinnias, cosmos, marigolds, sunflowers, cleome - even glads and get bloom this year. I do it all the time because some of them start to look tired in August/September and you get another fresh flush of blooms....

Lynne

Glads especially can be planted now and at two week intervals until mid July so you'll have cutting flowers until late fall.