Many flowers will bloom longer or bloom again after a short rest if the spent flower stems are removed once the blossoms fade.
Wildflowers such as Penstemon may be longer-lived if the spent flower stems are removed before the plants put energy into producing seeds.
Unwanted self-sowing can also be prevented by cutting back plants after they bloom but before they form seeds.
Flowers in habitat gardens may be allowed to set seeds to provide food for wildlife and cut back after the banquet is over.
An extra deep watering or two may keep plants in bloom longer, especially if the weather has been hot and windy with little rain.