My 2nd favorite perennial ever. I've had the same one at my folks house for 7 years and she does NOT have a green thumb. Blooms from May til Halloween, no joke! This is Early Sunrise Coreopsis. The more sun, the better! Zone 3-9
Coreopsis. One of the easiest-care perennials. Long bloomer, starting up in summer and continuing through autumn. Daisylike flowers bloom in bright yellow, but there are also varieties with golden yellow, pale yellow, pink, or bicolor blooms. Deadhead flowers to encourage additional bloom. Zones: 3-9.