I have mine planted in full sun and sometimes the sun can be quite intense. Years when it has been cooler, it has done better. Nevertheless, I'm going to move mine to the side of the bed where it will get only a few hours sun instead of full sun all day. Marg

From what I've observed over the years, it's pretty much just what they do -- after they flower, they get floppy, the tops yellow, they try to grow seed pods. I always just cut them off to the ground, and new stalks grow and often will flower if it's a moist summer. I've got all colors of them, light and dark blue, white, magenta purple, pinkish purple.

I have this problem and I thought it was because I had it growing in the sun. My mom and grandma also grew it with no problems and theirs was always in the shade, always luch green even after flowering. I moved mine to the shade and it still does the same thing. I wonder if the plant I have is a cultivar that is just not as heat tolerate as my mom's (which came from my grandma's). Mine came from a nursery. Mine is medium purple and looks like my mom's but they could be very different.

If you can find the native blue spiderwort, tradescantia ohiensis, I find that it is very upright and rarely flops. I grow mine in part shade and the plants remain good looking for a long time, and keep blooming too.

unfortunately, i think that's what spiderworts do! i love them - and hate them for that reason. i just cut mine back when they get ugly and they regrow in a short period of time. here's a good link - http://www.ehow.com/how_6979336_cut-back-concord-grape-spiderwort.html

It's what spiderwort does. When it begins to look too tatty for the gardens, take a pair of shears and cut it back severely, within a few inches of the ground.
The plant will put on new growth and will be a blooming machine again by the autumn.