Creating a wonderful scrim of gray and amethyst, Russian sage bursts forth in late summer or early autumn, rising 3 to 5 feet tall. It's an excellent companion to roses putting forth a final burst of bloom, to ornamental grasses, or to tall sedums. As long as it has good drainage, it is extremely low-maintenance.
Beginning to flower in midsummer, this plant blooms earlier and produces stouter plants than the similar species, Helianthus (often called perennial sunflowers). This plant also tolerates poor, dry soil and partial shade better than its taller cousin. Its numerous varieties bear semi-double or double flowers in yellow and yellow-orange with greenish-yellow or brownish-yellow centers, flowers from July until first frost. All make great cut flowers. Its dark green foliage has a coarse texture. It is shrublike and spreads to form extensive clumps. Plant in any well-drained soil.
Butterflies will flock to your garden when when you add the appropriately-named butterfly weed. Its clusters of orange, yellow, pink, and vermillion flowers appear in mid- to late summer, and are followed by thin, ornamental seed pods. Butterfly weed can reach 1 to 3 feet in height and is slow to emerge in the spring so mark its location well. Fairly drought-resistant, butterfly weed grows in many conditions except in soil that is wet or has lots of clay. It's a durable plant that is not susceptible to many pests or disease.
A terrific choice for the fall garden, boltonia grows 3 to 7 feet tall, depending on the cultivar, with a frothy explosion of white or pink flowers in late summer or early fall. A native flower, it's easy to grow as long as it has plenty of sun and good drainage. It's an ideal choice for the back of the border and combines well with other fall-blooming plants.
A good choice for beds, edgings, mass plantings, and containers, mealycup sage is an easy-to-grow annual known for its showy flower spikes in rich blue or silvery white that bloom from midsummer to frost. It grows 1 to 3 feet tall, depending on soil fertility, moisture, and the species.
Heliotrope is grown as an annual in Zones 2 to 9 and as a perennial in Zones 10 to 11. It bears wonderful clusters of purple or white flowers, which are intensely fragrant with a deep, grapey smell. Leaves are glossy and attractive with slight ribbing. The plant will grow a foot or two high as an annual, or up to 4 feet tall as a perennial, depending on the variety.
Garden stalwarts, zinnias have been a favorite for generations. They're a snap to start from seed and their bright colors are wonderful for late-summer bouquets. Dwarf types grow just 6 inches but others can grow up to 3 feet. Zinnias are ideal for attracting butterflies, who feast on their nectar. Common zinnia (Zinnia elegans) is the best known but narrow-leaf zinnia (Zinnia angustifolia) is quickly gaining in popularity because of its low, sprawling habit.
Even if you've never gardened before, you can grow yarrow with little effort. Yarrow is an amazing perennial that is hardy throughout most of the United States and can withstand heat, drought, and cold. It's valued in the garden for its ferny, gray-green or dark green, spicy-scented foliage and showy, flat-topped clusters of flowers in pink, red, white, or yellow appearing from late spring to early fall. Fern-leaf yarrow (Achillea filipendulina) is one of the best flowers for drying. In fact, it will dry right in the vase. Common yarrow (Achillea millefolium) dries less well but like fern-leaf yarrow, is excellent for cutting. Common yarrow can be invasive in some conditions.
Like a flock of butterflies, the delicate pale pink or rosy cream flowers of gaura bob and dance on long wand-like stems ranging from 3 to 7 feet, depending on the species. This native of Louisiana, Texas and Mexico does well in poor soils with little water and blooms for many weeks, sometimes as long as late spring through frost.
Snow-in-summer's striking combination of snow-white blooms covering low silver foliage can stop passersby in their tracks. Blooming in late spring or early summer, it's an excellent plant for any sunny, well-drained spot, such as a raised bed, rock garden, or wall, and is good in combination with spring-blooming bulbs.