Agastache 'Blue Fortune' (Giant Hyssop) is a top pick for gardeners. This upright deciduous perennial is prized for its long flowering season, showy flower spikes, licorice-scented foliage, low maintenance, and deer resistance. A crowd-pleaser that is also adored by bees, hummingbirds, and butterflies. Generally disease and pest free and resistant to deer and rabbits.

A very attractive dwarf variety, New England Aster 'Purple Dome' (Aster novae-angliae) features masses of semi-double, daisy-like, deep purple flowers, 1.5 in. wide (4 cm), with sunny yellow center disks, which can fully cover the plant. Blooming for 4 weeks or longer, from late summer to late fall, this eye-catching beauty easily enlivens any sunny corner of the garden. Native to North America, it is easy to grow, long-lived, brings cheerful fall color, and is a great source of nectar for butterflies. Typically grows up to 18-24 in. tall (45-60 cm) and 12-18 in. wide (30-45 cm). Perfect for small gardens. Deer and rabbit resistant!

For summer to fall exquisite beauty on easy care plants, few perennials can compare with Aster x frikartii 'Monch' (Frikart's Aster). One of the first Asters to bloom, this lovely perennial plant creates a bold splash of color in the landscape over an extraordinarily long season with masses of attractive, soft lavender-blue, star-shaped blossoms, 2 in. wide (5 cm), with slender rays and golden-yellow centers. Such a gentle color that it blends with almost any other color in the garden. Free flowering, well-branched with sturdy stems that do not need staking, this aster is easy to grow, trouble-free, mildew-resistant and a great source of nectar for butterflies!

Bushy, well-branched, with one of the longest blooming seasons, Red Valerian (Centranthus Ruber) is a popular perennial grown for its ornamental and showy star-shaped flowers. Fragrant, this border beauty is also easy to grow, fairly pest and disease free and attracts butterflies. What else to ask for? A prolific bloomer from early summer to fall, it produces abundant, rounded clusters of crimson ('Coccineus'), pink ('Roseus') or white flowers ('Albus'), rising atop a blue-green, lance-shaped foliage.

Among the most popular reblooming Daylilies, multiple award-winner Hemerocallis 'Stella de Oro' ranks very high! Why? It is compact, vigorous, fragrant and enjoys profuse blooms over an extremely long blooming period. This Miniature Daylily produces masses of golden trumpets, up to 2.75 in. wide (7 cm), with ruffled edges and small green throats atop mounds of arching, blade-like leaves. This diploid Daylily is dormant (deciduous). Blooming from early summer to fall, this clump-forming deciduous perennial grows up to 11 in. tall (28 cm) and spreads slowly via rhizomes to 12 in. (30 cm). Won multiple prestigious awards including the Silver Stout Award.

A North American native that is perfect for the late summer garden, Lobelia siphilitica (Great Blue Lobelia) is a popular, upright perennial which produces long-lasting spikes of bright blue flowers atop a finely-toothed, lance-shaped foliage from late summer to mid-fall. Quite an architectural plant that adds vertical interest to the landscape. The nectar and pollen of the flowers attract primarily hummingbirds, bumblebees, and other long-tongued bees. Extremely hardy, low care, and fairly pest and disease-free, Great Blue Lobelia tends to be short-lived, although it may self-seed in ideal growing conditions (without becoming invasive).

Eye-catching, with maybe the deepest and purest blue flowers in the world of plants, Salvia patens (Gentian Sage) is an erect, tuberous perennial with showy racemes of slightly nodding, 2-lipped blue flowers. Blooming from mid-summer to mid-fall, the blossoms are borne above the foliage of ovate to triangular mid-green leaves. Salvia patens is fairly pest-free and low maintenance. Add this charming and graceful perennial to the landscape, and you will be rewarded with abundant butterflies, hummingbirds, and pollinating insects. Native to Mexico.

Lamb's Ears (Stachys byzantina) is a wonderful evergreen perennial, mostly grown for its rich rosettes of showy, velvety, silvery tongue-shaped leaves, resembling lamb's ears and bringing interest to the border. Pink-purple flower spikes appear in late spring or early summer. Their fuzzy flowers add textural interest, but cutting them off promotes foliage growth and improves the plant's vigor.

Incredibly pretty and exotic-looking, Tricyrtis formosana (Toad Lily) is a shade-loving perennial with small, orchid-like flowers, 1 in. long (2.5 cm). The blooms feature six showy white tepals, heavily sprinkled with purple freckles and a yellow throat. Quite showy, they are born in lax clusters at the top of erect stalks and sparkle in the garden in late summer to early fall. The foliage of shiny, lance-shaped, dark green leaves usually remains attractive throughout the growing season. Tricyrtis formosana is regarded as a top performer in the 2001 Chicago Botanic Plant Evaluation study as a result of its superior floral display, robust habit, winter hardiness and disease resistance.

Native to North America and Central America, Helenium is a great perennial for the late season garden as it provides weeks of splashes of color, from early summer to early fall, when many other perennials are starting to fade.

Late summer and early fall often represent a challenge to gardeners as summer-blooming plants begin to fade while fall bloomers have not quite reached their apex. Fall-blooming anemones, commonly called Japanese Anemones or Windflowers, are fabulous perennials, helping with this transition from one season to the next.

Monarda has very distinctive, brightly colored flower-heads that create impressive border displays and provide a great impact when used in a mass planting. The blooms consist of asymmetrical, two-lipped tubular flowers borne in dense, globular terminal heads, which rest upon a whorl of decorative bracts that attract scores of butterflies and hummingbirds. It is also grown for its aromatic foliage that can be enjoyed in salads or simply by passing by.

Rudbeckia hirta, commonly known as Black-Eyed Susan, Gloriosa Daisy or Yellow Oxeye Daisy is a cheerful, widespread wildflower that belongs to the Asteraceae family. It is renowned for its showy golden-yellow or orange-red, 2-3 in. wide (5-7 cm), daisy-like flowers with dark chocolate central cones. The single or double blooms rise atop sturdy, upright, scattered stems. Their foliage of oval green leaves is covered with bristly hairs that give it a slightly rough texture. Black-Eyed Susans flowers are attractive to butterflies, bees, and other pollinators and beneficial insects. They are considered deer-resistant plants due to their typically rough leaves and stems.