Misbehaving stipa

I love these grasses and use them throughout the garden. They look very special among perennials. But a recently planted, quite large specimen seems to have "opened out" and is sprawling all over a fuchsia. It has been very dry here for the last two weeks - and we have been away. Do you think dryness is the problem? I know these grasses sometimes do this later in the year but not in June....