With trumpet-shaped yellow flowers all season, this tough perennial thrives in hot, dry conditions and creates a stunning combination with blue ornamental onion.
Noted for its reliable show of snowy-white flowers in both spring and fall, this tall bearded iris is easy to grow and bears ruffled blooms on 30-inch-tall stems.
Enjoy lilac's fragrance in spring and again from midsummer into fall with this compact variety, which bears a heavy crop of lavender-purple flowers perfect for cutting.
Unlike most hydrangeas, Endless Summer blooms on new growth, ensuring a spectacular show of flowers several times each summer, even in cold climates.
Beautiful and virtually disease-free, Knock Out roses bloom almost continuously through the summer. Shown here is Pink Double Knock Out, part of a series that includes various colors.
Jazz up your garden with royal purple petals covering the Jackmanii clematis in early summer, with sporadic blooms throughout the season.
Putting on a show of deep purple spires in late spring, May Night salvia can bloom again later in summer if you remove fading flowers.
Perfect for small-space gardens, this perennial blooms all summer, slowing down during the warmest days but picking up the pace again in autumn.