Texas Gardening: Shasta Daisy issue with long stems, 1 by TXSkeeter

TXSkeeter wrote:
Having a problem this year with two groups of Shasta daisies... one group large and one group small. It seems that the stems on these plants have grown extremely long and bare for all practical purposes, leaving the stems to flop over into the surrounding greenery. The plants seem healthy enough and while the number of blooms is rather light this year, the plants are putting forth blooms and leaves as one would expect.
The larger group of plants is about two or three years old and has done well until lately when the flopping stem thing started. I was going to dig and divide this grouping late last fall but never felt it was dormant enough to do so although I did eventually cut the whole batch almost to the ground.
Have grown Shastas before and never had a problem so what am I doing wrong or better yet, what do I need to do to get this batch of plants back on track and pretty again? If it involves cutting all stems back to the ground or even digging up the whole planting, culling and then replanting, I'm at the stage where I'd be happy to do so even if it means losing blooms for the rest of the growing season.
Any advice will be most appreciated.
I've attached an image taken earlier today showing the problem.
Steve E