For gardeners, 'Chelsea' doesn't just mean the Chelsea Flower Show. It's also a reminder to give several plants the 'Chelsea chop', cutting them back by a third in Chelsea week. This looks drastic, but means more flowers and bushier plants a little later in the season, which will not be so inclined to flop.
Here is my Nepeta 'Walker's Low' before and after I set to with shears. And Bella rolling all over the prunings, delirious with the smell! Other plants that respond well to this treatment include sedums, such as Sedum 'Matrona', which tends to flop apart, exposing the middle of the plant.