Spindly Veronica

The veronica in our front garden have been poor this year. They have been quite spindly, so much so that many of them have collapsed and just laid on the ground usually they have been quite sturdy plants with only the odd one collapsing. Also the flowers have not lasted anything like previous years. Can this be put down to the late frosts and extremely strong sun or do the plants need to be replaced?, they have been in place 10 years.