Are you growing it in a shady place. They like sun and some will take a bit of parted shade. I never trimmed one. They just grow wild here and there all over. In a mound.

They get plenty of sun... they have a taproot and I don't know if they send many shoots up from the ground... maybe I'll just let it limp along til fall and then cut it back and see what happens. Where are you that they grow wild?? I have actually had trouble finding them in nurseries.

If you prune it back by at least half it will force latent buds closer to the root to grow. This should thicken and bring your blackfoot back into shape if it is getting enough sun. Otherwise you may consider moving it to a sunnier location. Good drainage is important as well.

Happy Growing David (If you have not feed them this season this also may be a good time to charge it up a bit. They do respond well to organic or chemical fertilizers.)

I moved mine last fall and in the process cut them back severely. They looked all the better for it this spring. I am getting ready to do it again, but as I haven't done it in late-spring/summer before, I can't comment as to how it might affect bloom.

To answer you about where I live that Blackfoot daisy grow wild. I live about 30 miles southwest of Austin in the walnut limestone outcropping, high uplands. Limestone rubble, caliche, nothing special. I do not do much with them. I don't trim them, water them or plan them into my plantings. I don't rip them out either . They are welcome inhabitants. I did just take a break and I went out what looks like seed.- mara