Armeria maritima (Sea Thrift) is a compact, evergreen perennial boasting round clusters of pink to lavender (or sometimes white) flowers borne atop slender stalks that rise well above the foliage. Blooming profusely in mid to late spring, sporadic additional flowering may occur throughout the summer. Sea Thrift forms a dense, mounded tuft of grass-like, dark green leaves that will spread slowly. A charming little plant that is ridiculously easy to grow and is perfect for edging walks or borders. The flowers can be used as cut flowers too.

One of the most popular foliage plants, award-winner Artemisia schmidtiana 'Nana' is a compact, semi-evergreen perennial forming a low, spreading mound with soft, silvery leaves divided into hair-like segments of extremely fine foliage texture. Tiny, yellow nodding flower-heads appear in mid or late summer, but they are ornamentally insignificant and are best cut off to keep the foliage at its best. A great choice as a neutral spacer or framing plant, Artemisia schmidtiana 'Nana' is a graceful addition to the landscape. One of the few Artemisia that is not invasive by underground rhizomes.

Easy care, drought tolerant and deer resistant, Asclepias tuberosa (Butterfly Weed) is a bushy perennial prized for its brilliant clusters of bright orange to yellow-orange flowers which bloom continuously throughout summer. Sitting atop upright flowering stems clad with stiff, lance-shaped leaves, the colorful umbels, 2-5 inches across (5-12 cm), are followed by attractive seed pods in fall. The abundant foliage provides a dark-green backdrop which nicely compliments the cheerful flat umbel flowers. Butterfly Weed has no milky sap, unlike many of the other milkweeds.

Tough and durable, Baptisia australis (False Indigo) is an upright perennial with a long season of interest. In spring, this native to the North American prairies bears spikes of pea-shaped indigo blue flowers, resembling Lupines. They last for about three weeks and attract butterflies, bees, and hummingbirds. When the flowers fade away, the lovely blue-green, trifoliate leaves remain neat and form a lovely backdrop for the other perennials in the garden. If left untrimmed, the plant forms interesting seedpods turning deep black in the fall and persist into winter.

Resembling wine cups, Callirhoe involucrata (Purple Poppy Mallow) decorates cheerfully the landscape in late spring and early summer with its masses of brilliant magenta cup-shaped flowers atop ground-hugging stems. The eye-catching, upward-facing blossoms, up to 2.5 in. wide (6 cm) open in the morning, close in the evening and remain closed after pollination. Poppy-like, they consist of 5 petals with a white spot at their base surrounding a prominent central column of stamens. Evergreen in mild climates, the unique and striking foliage of deeply lobed, palmately divided (hand-shaped), green leaves adds some winter interest to the border. Mat-forming, this native prairie plant is an attractive, spreading, drought-tolerant perennial.

The flamboyant, rich blue flowers of Centaurea montana, known as Mountain Cornflower or Bachelor's Button, are pretty additions to the garden. This attractive perennial plant features showy blue, fringed flowerheads, 2 in. wide (5 cm), with reddish blue, thistle-like centers from late spring to early summer and usually blooms again in late summer - fall if plants are cut back hard after the first flush. The foliage consists of simple or lobed, silvery green leaves.

Blooming profusely in late spring and early summer, Cerastium tomentosum (Snow-In-Summer) is a low-growing, short-lived perennial that forms a dense mat of silvery-gray foliage dotted with star-like, pristine white flowers with notched petals. Evergreen, it spreads quickly by reseeding itself and makes a great ground cover for sunny areas.

Indispensable element of waterwise landscapes, Delosperma 'Fire Spinner' (Ice Plant) is a vigorous, spreading perennial creating a stunning carpet of attractive succulent foliage, covered in late spring to early summer with a profusion of brightly colored flowers, 1.5 in. across (4 cm), which keep reappearing all summer until fall. Evergreen in warm winter areas, the striking foliage of fleshy, medium green leaves, delicately covered with transparent flakes resembling small pieces of ice (hence the common name), adds winter interest to the landscape. The intensity of the flower color, an incredible mix of brilliant orange and magenta petals with a central white eye, combined with the long blooming season and evergreen foliage reinforce the ornamental interest of this perennial plant.

A fabulous little plant that you should not be overlooked! Among the purest of garden whites with its abundant clusters of 4-petaled white flowers, enhanced by delicate yellow dots on each petal and standing out starkly against the dark green, leathery, evergreen foliage, Iberis sempervirens is an enchanting low, sprawling, woody-based perennial that will charm your garden for weeks in spring and early summer.

Valued for its showy fluffy vertical flower spikes contrasting with a lush, finely textured, grassy foliage, Gayfeather or Blazing Star (Liatris spicata) is a perennial of great ornamental value. Interestingly flowering in succession from top to bottom over 4 weeks and more, its button-shaped, purple, rosy red or white flowers resemble blazing stars (hence its common name). Attractive to bees, butterflies and hummingbirds, this beautiful native American enjoys a long season of interest from mid summer to fall and supplies winter bird food. The narrow, opposite leaves stay attractive all summer and turn a rich bronze in fall. Easy to grow and low care, Liatris spicata adds a strong vertical accent in sunny borders or prairie gardens. It helps create outstanding combinations with the warm golds of Rudbeckia or the purple blossoms of Echinacea.

Very free flowering and one of the tallest, Nepeta 'Six Hills Giant' (Catmint) is a vigorous herbaceous perennial noted for its billowing, aromatic, gray-green foliage that is topped with 9-12 in. spikes (22-30 cm) of rich violet-blue flowers in early summer with repeat blooms throughout the growing season. Although the stems are 2-3 ft long (60-90 cm), the arching habit of this Nepeta brings the height down to 18 to 24 inches (45-60 cm). Plant large drifts of Nepeta 'Six Hills Giant' along a walkway to create a garden space that overflows with color and enjoy its lemon scent when bruised!

This showy evening primrose, is a sprawling perennial that will turn heads. It is packed with very large, mildly fragrant, bright yellow flowers that rise atop a foliage of narrow lance-shaped leaves with conspicuous silvery midribs. Blooming profusely from late spring to early fall, the flowers open for only one day, usually late afternoon and wither the next day. They are followed by very distinctive seed pods bearing 4 papery wings, ready to be blown out by the wind. Winter hardy, this low-growing perennial grows only 6-12 in. tall (15-30 cm) and spreads 12-18 in. (30-45 cm).

Vigorous and showy, Oenothera speciosa (Evening Primrose) is a sprawling perennial featuring masses of fragrant, bowl-shaped, satiny white flowers, with the delicate texture of crumpled silk. Large, 2-3 in. wide (5-7 cm), the pretty flowers age to rose-pink with deeper pink veining. They rise on erect to sprawling stems atop rosettes of oblong to lance-shaped, toothed, medium green leaves. Blooming profusely from late spring to early fall, the flowers open in the evening and remain open until late morning. They are followed by oval seed capsules bearing 4 papery wings, ready to be blown out by the wind. A valuable plant for its ability to grow in poor soils and tolerate drought.

Perovskia atriplicifolia (Russian Sage) is a bushy, woody-based deciduous perennial with long terminal panicles of small, lavender-blue flowers, borne on thin white stems, clad with finely-dissected, aromatic gray-green leaves. Blooming for weeks from mid-summer to fall, this delicate-looking plant is a toughy that is resistant to drought, heat, pests and poor soils. Pretty and excellent for xeriscaping, its long blooming season, makes it an extremely valuable addition to the garden - even in winter when the stems create a beautiful feature in the landscape.

Award-winning Pulsatilla vulgaris (Pasque Flower) is a lovely early-blooming perennials, which bears a profusion of large, showy blossoms (2-3 in. wide or 5-7 cm) on short stems in spring. A single plant may thrust over 30 blossoms over a couple of months! The attractive bell-shaped blossoms, in shades of blues and purples, contrast beautifully with the luminous boss of golden yellow stamens. They are followed by equally ornamental, plume-like seedheads (resembling those of clematis) in fluffy spherical clusters. Its ferny, silky foliage remains attractive throughout the growing season. Pasque Flowers will seed themselves all over, if you are lucky, then go summer dormant. Enjoying a long season of interest, these low growing plants are suitable for rock gardens or the front of the perennial border. They combine well with spring-flowering bulbs and ground covers.

Santolina or Lavender Cotton (Santolina chamaecyparissus), a favorite of Mediterranean gardens, is a beautiful evergreen shrub noted not only for its dense, fine, silvery gray-green foliage all year around but for its drought tolerance. Blooming occurs in summer with a display of small button-like bright yellow flowers, but Santolina is mostly grown for its foliage.

Marking the end of summer with its sprays of bright yellow flowers, Solidago rugosa 'Fireworks' (Rough Goldenrod) is a clump-forming perennial that provides a bold splash of color in the late season garden. Blooming for weeks from late summer to late fall, this eye-catching beauty features arching flower panicles that resemble fireworks cascading off the plant. They are a great source of nectar and pollen, attracting various species of insects, including small bees, wasps, flies, small butterflies, skippers, and beetles. The fine-textured leaves emerge burgundy in spring and change to dark green in summer. Ornamental throughout the season, Fireworks is subject to less spreading than the species, and can be mixed with other perennials without fear of it becoming invasive.

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.

Blooming its heart out from late spring to frost, Award-winning Verbena 'Homestead Purple' is one of the most popular trailing verbenas with its indefatigable clusters of rich, bright purple blossoms so useful at filling large areas of one's yard! The glossy, dark green foliage creates a lovely foil for the slightly fragrant purple flower heads. Easy to grow, resilient to most pests and diseases, this low maintenance plant is also drought, heat, dry soil and rocky soil tolerant!

Named after Achilles, hero of the Trojan Wars in Greek mythology, who used yarrow to heal the wounds of his soldiers, Achillea is valued for its pleasantly fragrant, feathery foliage and its long-lasting, conspicuous, flat umbel flowers. Vital ingredient of herbaceous borders, cottage gardens, meadows or prairies, Achillea typically blooms for weeks from late spring to late summer, in a wide range of colors. Easy care, drought, deer and rabbit resistant, Achillea is rich in many qualities!

Eye-catching, Anthemis tinctoria is a vigorous perennial that will light up your garden throughout summer and sometimes into fall with its abundant blooms of shining golden yellow flowers atop a fragrant lacy foliage. A low-maintenance plant, it adds long-lasting color and contrast to the summer perennial border.

Providing a bold splash of color in the late season garden with its masses of lavender-blue starry flowers, Italian Aster (Aster amellus) is one of the first Asters to bloom, doesn't need staking and is not sensitive to mildew. Native to Europe, it is easy to grow, is long lived, brings cheerful fall color and is a great source of nectar for butterflies! As opposed to the New England Aster (Aster novae-angliae) or the New York Aster (Aster novi-belgii), it doesn't produce tall, pyramidal plants but the size and beauty of its blossoms, coupled with its neat and compact habit, make the Italian Aster among the most desirable of all Fall Asters.

Providing an outstanding late season show with its masses of violet or lavender daisy-like flowers, New England Aster (Aster novae-angliae) is one of the tallest and most spectacular of the Asters. Native to North America, it is easy to grow, long lived, brings cheerful fall color and is a great source of nectar for butterflies.

Coreopsis, commonly known as "Tickseed", are prized by many gardeners for the bright colors of their flowers and their ability to put up with most garden soils. There are over 100 species available and countless hybrids, including both annuals and perennials. Most of them are low maintenance, drought tolerant and enjoy a long blooming season, generally from early summer to fall, or even longer if deadheaded. Native American Coreopsis are not only workhorses in sunny borders, they also make excellent cut flowers.

Tough as nails, Coneflowers (Echinacea) are wonderful additions to the landscape with their brightly colored blossoms to be enjoyed over a long flowering season. Simple to grow, mostly trouble-free, thriving on neglect, these members of the Asteraceae family (along with daisies, sunflowers and asters), are reliable performers that are tolerant to almost everything! Loved by butterflies, birds and bees, Coneflowers have won the hearts and minds of many gardeners and are increasingly in vogue as garden perennials, as cut flowers or landscape plants. They enjoy such a long list of virtues that should not be overlooked!

Drought tolerant and delightfully colorful, Blanket Flowers (Gaillardia) are short-lived perennials renowned for their profuse, long-lasting, colorful mounds of bright, single or double daisy-like flowers atop an attractive gray-green foliage from early summer to fall. Named after the native Indian blankets, whose color pattern they resemble, their 2-3 inch wide flowers (5-7 cm) are a real magnet to hummingbirds and butterflies!

Native to Texas and Louisiana, Lindheimer's Beeblossom (Gaura lindheimeri) is a remarkably pretty perennial plant with tall, airy-looking flowers giving the appearance of butterflies floating in the garden. It adds a unique texture in the garden with its 4-petaled, pink tinged or white, 1 in. long (2.5cm), butterfly-like flowers borne at the top of the airy spikes. Enjoys a long blooming season, typically from early summer into fall. Forms a lovely vase-shaped clump of erect or arching, densely clustered wand-like stems. Tolerates drought, heat, humidity, partial shade and dry soils. Deer and rabbit resistant, Gaura attracts butterflies and hummingbirds.

Adding fabulous color and form to the early summer border, hardy perennial salvias are mostly represented by the hybrids of Salvia x sylvestris (Woodland Sage) and Salvia nemorosa. With their vertical, densely packed flower spikes, ranging from rich indigo-blue to violet to purple, these hardy salvias contribute to create incredibly beautiful and contrasting combinations with other perennials and ornamental grasses. Butterflies and hummingbirds love them as they enjoy sipping the nectar from their tightly bunched whorls of flowers.

Sun-loving, easy to grow, hardy, heat and drought tolerant, False Sunflowers (Heliopsis helianthoides) have plenty of qualities and appeal! Valuable additions to the landscape with their profusion of bright golden daisies (2-3 inches wide, 5-7 cm) on display for 6 to 8 weeks all summer until early fall, they also feature a lovely foliage that is pleasant to the eye. Use them to brighten up a sunny area of the garden or in a vase where they will last a couple of weeks!

Often called the 'perfect perennial' because of its numerous qualities: showy flowers, wide array of vibrant colors, drought tolerance, heat stress immunity, ability to grow in most hardiness zones and low care requirements, Daylily (Hemerocallis) is a remarkable and stunning addition to the garden! Each flower typically lasts no more than 24 hours, opening up in the morning and withering during the forthcoming night, possibly replaced by another one on the same flower stalk the next day.

Often associated with the famous purple fields of Provence, Lavandula angustifolia, also called English Lavender, is not native to England but to the Mediterranean. Ideal for garden borders, cooking and potpourri, this lavender also produces the best oils. Delightfully fragrant when brushed against or crushed, this lavender is celebrated for the wispy inflorescences that adorn the tip of each upright stem from late spring to late summer, creating lovely drifts of "cool" colors that sway in the summer breeze.

Highlights of the garden from late spring to early summer, Oriental Poppies (Papaver orientale) are truly eye-catching perennials with their huge, silky-satin flowers in shades of red, orange, white or pink. Planted in small groups, their bold blossoms will give a colorful punch to your borders and draw the attention! The seedpods that follow the fading flowers are also quite attractive and can be used in dried flower arrangements or left in the garden for the visual interest they bring!

Providing fantastic warm colors in the late summer garden, Rudbeckia fulgida are herbaceous perennial boasting golden yellow flowers with prominent, brown or black central cones. Blooming profusely from mid summer through early fall, they are borne atop sturdy stems and literally cover the foliage of lance-shaped, deep green leaves. Their joyous color range is fairly limited - from yellow to orange-yellow - but they differ in height and habit. Extremely easy to grow, they look stunning next to the cool blue colors of Geranium, purplish Asters or the soft tan ornamental grasses.

Sedums are almost the perfect plants. Vigorous, carefree, good-looking, with a season of interest lasting more than 6 months, who could resist? Even the bees and butterflies can't! These standout perennials grow more or less erect, up to 2 ft. (60 cm), and form a clump of thick, fleshy sage green to blue to dark red foliage topped with flower buds resembling broccoli. Gradually, these densely clustered buds reveal tiny, star-like flowers, in shades of white, pink or red, in late summer or early fall. As the weather cools, their colors grow deeper and richer. Both foliage and dead inflorescences remain attractive through winter, providing some additional interest.