Perennials

There are probably at least a hundred perennials that will thrive in your garden — but this sampler gives you a good starting point as you begin to build your collection. The group includes some of the most popular perennials grown today.

Susan A. Roth
Astilbe

• Zones 1-7, 14-17, 32-45
• Partial to full shade; accepts some sun in cool summer climates
• Regular watering

Mainstays of the summer shade garden, astilbe provides both bright flower color and attractive foliage. Feathery, plumelike flower clusters in white and a wide range of pink and red shades emerge from loose clumps of toothed, dark green, almost fernlike leaves. Heights vary, but plants typically average 2 to 3 feet tall and wide. By planting varieties with staggered bloom times, you can enjoy flowers from late spring through summer's end.

Astilbe needs rich, moist, well-drained soil. It does best in shade but tolerates sun if temperatures are fairly cool and sufficient water is provided. Survival in the coldest zones (1, 43, 45) depends on good snow cover. During the growing season, apply a complete fertilizer regularly (monthly to bimonthly, depending on soil). Divide clumps when flower production lessens, usually every 3 to 5 years.

Charles Mann
Rudbeckia fulgida 'Goldsturm'

• Zones 1-24, 26-43
• Full sun
• Regular to moderate watering

Bright colored and easy to grow, black-eyed Susan is covered with 3- to 4-inch-wide, dark-centered yellow daisies from midsummer until late fall. The flowers are borne on multibranched, 2- to 3-foot stems that rise from a 2-foot-wide foliage clump; leaves are medium green, elliptical in shape, up to 5 inches long. Cut for bouquets or deadhead during the season to prolong bloom, but leave the last blooms of summer in place; the dark centers that remain after petals drop can be used in dried arrangements or left on the plants as food for birds.

Black-eyed Susan grows well in ordinary garden soil, spreading by underground rhizomes to form large clumps (you can remove newly emerging plants if they overreach their boundaries). Divide clumps when they lose vigor and their centers stop growing and blooming (every 4 to 5 years or so).

Saxon Holt
Phlox paniculata

• Zones 1-14, 18-21, 27-43
• Full sun; flowers may fade in hot-summer climates
• Regular watering

Border phlox is deservedly popular for the showy, dome-shaped clusters of fragrant flowers it produces throughout the summer. Plants reach 2 to 4 feet tall and almost as wide, making a dramatic addition to the border. Leaves are dark green, 3 to 6 inches long; individual flowers are just about an inch across and come in a wide variety of colors.

Given the growing conditions it needs, phlox will reward you with healthy foliage and a long bloom season. Soil must be rich and well drained; dig planting beds deep and amend well with organic matter such as compost or well-rotted manure. Fertilize annually in spring. Deadhead spent blooms, since seedlings will not bloom true to the parent. Divide every 2 to 3 years, replanting only divisions from a clump's edges.

Powdery mildew can cause serious problems in hot, humid areas. To combat it, plant mildew-resistant varieties such as 'Ice Cap'. Cut mildew-infected plants to the ground each fall; then discard the cut-off portions and any debris.

Charles Mann
Nepeta faassenii

• Zones 1-24, 30, 32-43
• Full sun
• Moderate watering

Catmint blooms from mid- to late spring into summer, when loose spikes of small, clustered flowers form a lavender blue haze above the undulating mounds of soft gray-green, 1-inch leaves. The delicate-looking plants provide a nice contrast to larger, stiffer flowering perennials and annuals; they're an excellent underplanting for roses, too. And in cold-weather climates, they offer an alternative to lavender (Lavandula).

Catmint needs only moderate watering, but will take more if soil is well drained. If dead flower spikes look unsightly after the first flush of bloom, cut them back with hedge shears; this may encourage a second bloom in late summer. If the whole plant looks untidy and floppy after bloom, shear it back by two-thirds. Division is rarely required.

Charles Mann
Geranium endressii 'Wargrave Pink'

• Zones vary
• Full sun or partial shade; must have afternoon shade in hot-summer climates
• Regular watering

Not to be confused with common garden geranium (Pelargonium,) the cranesbills include spreading, mounding, and upright plants that make beautiful additions to the summer garden.

Flowers are five petaled, often in shades of rose, blue, and purple; a few varieties have pure pink or white blooms. Beaklike fruits follow the flowers, hence the common name "cranesbill." Leaves are roundish or kidney shaped, shallowly or deeply lobed.

One excellent choice is G. endressii (Zones 1-9, 14-24, 31-43), a 1- to 1 1/2 footer that blooms from late spring to fall (to early summer in hotter regions); its variety 'Wargrave Pink', with salmon pink blooms, is most widely grown. Also popular is G. sanguineum (Zones 1-9, 14-24, 30-43), a spreading, trailing plant to 11/2 feet high, 2 feet across, with deep purple blooms from late spring into summer.

Cranesbills grow best in cool- and mild-summer regions, where they will tolerate full sun or light shade. Where summers are hot, provide afternoon shade. Give moist, well-drained soil. Clumps can be left in place for many years before blooming declines due to crowding; when this happens, divide in early spring.

Claire Curran
Delphinium elatum

• Zones 1-10,14-24, 32, 34, 36-41
• Full sun
• Regular watering

Delphinium's majestic bloom spikes are a mainstay of many summer gardens. Flower color covers the full range of blues and purples, and you'll find cool pinks, cream, and white as well. Individual blooms are flat, to 2 inches across, borne in narrow, upright spikes. Leaves are dark green and deeply lobed. The tall-growing cultivars of D. elatum are most widely grown; they form 1- to 2-foot-wide clumps and send up 5- to 6-foot flower spikes.

Delphiniums prefer cool, moist summers and chilly but not excessively cold winters. They need rich, porous, nonacid soil; if soil is acid, amend it to neutral before planting. Also work in organic matter and a high-phosphorus fertilizer. When new shoots appear in spring, remove all but the two or three strongest and apply a complete fertilizer. Stake flower stalks early. Cut back stalks after bloom, leaving foliage at the bottom; when new stalks emerge, fertilize again to encourage fall bloom.

Even under ideal conditions, delphiniums are usually short lived; dividing them each year in spring may prolong their lives. If grown outside their preferred climate, they're best treated as annuals. Plant in fall in mild-winter zones, and just after frost danger is past where summers are hot.

Besides cultivars of D. elatum, tall delphiniums include the Pacific Hybrids, with flower spikes up to 7 feet.

Hybrids of D. belladonna, such as 'Bellamosum', are somewhat hardier and less prone to disease than other delphiniums. Don't pinch or disbud these; just let them grow as they will. Their blossom spikes are shorter but more numerous than those of D. elatum.

Chinese delphinium (D. grandiflorum) is somewhat more forgiving of less-than-ideal conditions than D. elatum, though it does have the same soil and climate needs. It's a many-stalked plant that grows just 1 1/2 to 2 feet tall, bearing flowers in blue shades.

Saxon Holt
Anemone hybrida

• Zones 3-24, 30-39, 41
• Partial shade
• Regular watering

Prized for its late-summer bloom, this graceful plant bears loose sprays of slightly cupped, gold-centered white or pink flowers that resemble wild roses. Blossoms are single or double, 2 to 3 inches across, carried on 2- to 4-foot flower stems that rise from clumps of dark green, softly hairy foliage. Leaves are three to five lobed, up to 6 inches across. Foliage clumps are low in early spring, then increase in height as the season progresses. Japanese anemone is especially attractive planted in front of deep green shrubbery, where its flowers stand out dramatically against the dark backdrop.

Japanese anemone prefers good, well-amended soil; it will take claylike soil as long as drainage is good. Plants tolerate some sun in cool-summer climates but need protection from afternoon sun where summers are hot. Where winters are severe, mulch plantings heavily in fall.

Plants establish somewhat slowly but spread freely by rhizomes when mature; you can pull up new shoots to keep plants in bounds. Divide clumps every 5 to 7 years.

Joanne Pavia
Helleborus orientalis

• Zones 2-10, 14-24, 31-41
• Full sun in winter; partial to full shade for rest of year
• Regular watering

Lenten rose blooms late in winter, bearing nodding, 2-inch flowers in shades of whitish green, soft purple, or rose, often spotted with purple. The "petals" are actually sepals that shelter the tiny true flowers, which are nestled in the blossom center surrounded by a clump of yellow stamens. These petal-like sepals remain on the plant for several months, long after the true flowers have faded and seeds have set. Leaves are large (to 1 foot across) and dark green, divided into five to 11 tooth-edged leaflets; they're evergreen in mild-winter climates, though you may want to remove tattered foliage during fall cleanup. Both foliage and flower stems emerge from a central point; plants eventually form clumps about 2 feet tall and wide.

Grow Lenten rose in a spot that receives winter sun but is later shaded by deciduous trees or shrubs. It prefers rich, well-amended, neutral to alkaline soil. Don't fertilize more than once or twice a year.

Lenten rose can be divided, but doing so is not recommended, since divided plants take several years to recuperate. However, plants self-sow readily — so to gain additional plants, simply let spent flowers go to seed.

David Cavagnaro
Aster novae-angliae

• Zones 1-24, 31-43
• Full sun, partial shade in hot-summer climates
• Regular watering

Asters are on many a gardener's list of favorite fall-blooming perennials. They're easy to grow and add color to the landscape when most other flowers are winding down for the year.

This aster is a stout-stemmed plant 3 to 5 feet tall with hairy leaves to 5 inches long. Pink to deep purple flowers are 2 inches across; two favorite varieties are dark pink 'Alma Potschke' and deep lilac 'Treasure'. Stake plants early in the season to keep stems from flopping over. Compared to many other asters, New England aster is more tolerant of climatic extremes, taking high humidity and colder winter temperatures. It performs best in rich soil. It prefers regular water and will thrive even in wet soil; if it dries out too much between waterings, it's prone to mildew. Divide clumps every 1 to 3 years.

Doug Wilson
Papaver orientale

• Zones 1-11, 14-21, 30-45
• Full sun
• Regular to moderate watering

Oriental poppy blooms in early summer, bearing flamboyant bowl-shaped blossoms on leafy, 2- to 4-foot stalks that rise from a low mound of long, narrow, notch-edged, bristly looking (yet soft-to-the-touch) leaves. The flowers are 4 to 6 inches across. The original color was orange, but today you'll also find red, scarlet, pink, salmon, white, and bicolor blooms. One clump can grow almost 2 feet wide; three planted near each other make a dramatic splash of color at bloom time.

Though Oriental poppy is a favorite in many parts of the country, it needs winter chill for best performance and thrives in cold-winter, cool-summer regions. In these preferred areas, it's easy to grow, flourishing in ordinary garden soil (as long as it's well drained).

Plant Oriental poppy from roots or containers in early fall. Plants will welcome a springtime application of complete fertilizer during their first season.

Oriental poppy grows from a fleshy taproot and is not a good candidate for dividing. The preferred method for increasing a planting is to take root cuttings in summer.

Marion Brenner
Penstemon gloxinioides

• Zones vary
• Full sun; light shade in hot-summer climates
• Regular watering

These bushy, typically upright plants are fairly short lived--but to make up for it, they produce lots of color over a long period. The tubular, 1- to 2-inch-long flowers, popular with hummingbirds, are carried on leafy, semirigid stalks that rise from clumps of narrow, 3-inch-long leaves. Flower colors of penstemon species are red, orange, and blue, but cultivars have increased the range to include white, soft pinks, salmon, peach, deep rose, lilac, and deep purple. Plants generally grow as wide as they are tall.

Two widely sold species, both offering many cultivars, are P. barbatus (Zones 1-24, 31-43), reaching 2 feet tall and blooming from midsummer to fall; and P. gloxinioides (Zones 7-9, 14-24), a 2- to 4-foot-tall summer bloomer.

Grow penstemon in average to sandy or slightly rocky soil; be sure drainage is good. These plants aren't divided, but simply replaced every 3 to 4 years. Don't fertilize them — doing so shortens their already brief lifespan.

Saxon Holt

• Zones 1-11, 14-16, 32-45
• Full sun; partial shade in hot-summer climates
• Regular watering

Peony flowers are exquisite: large, showy, silky, single or double, available in colors ranging from white and pale cream through pink, red, and even pure yellow. Individual blossoms are as large as 6 to 8 inches across; many are fragrant. Bloom time comes from late spring to early summer; for the longest display, plant varieties with early, midseason, and late bloom. The plant itself is a shrubby, 2- to 4-foot clump of lush dark green foliage, with each 8- to 10-inch leaf divided into elliptical leaflets. In many areas, leaves turn golden yellow in autumn before the plants die back.

The bush-form ("herbaceous") peonies just described are all cultivars of P. lactiflora; hundreds are available. Most need winter chill to bloom well. In milder climates, gardeners will usually have better luck with the Japanese cultivars, a popular group that blooms successfully in warm-winter areas.

Peonies are extremely long lived: choose a permanent site where they won't have to compete with other plants, and you'll be rewarded with years of bloom. Give rich, well-drained, neutral to slightly acid soil. Plant the tubers in fall, setting them 2 inches deep in the coldest zones, 1 inch deep in warmer areas (don't plant too deeply; if you do, the peonies won't bloom). Mulch the planting area the first year after the ground has frozen. Plants may not bloom the first year.

Charles Mann
Echinacea purpurea

• Zones 1-24, 26-45
• Full sun
• Moderate watering

Striking flowers and a long summer bloom season make this carefree plant a favorite. A North American native, it forms 1 1/2-foot-wide clumps of hairy, rather coarse, deep green leaves that reach about 8 inches long. Borne on stiff, 1 1/2- to 3-foot stalks that never need staking, the 4-inch, daisylike flowers have rosy purple petals that droop slightly from a brownish orange, dome-shaped center; they're popular with butterflies. The bristly cones remain after the petals drop; some gardeners leave them in place to provide food for small birds.

Purple coneflower needs no special treatment, though it appreciates some shade in the hottest regions. It does well in ordinary garden soil. It grows from a rhizomatous taproot and is better left undivided; because it grows slowly, individual plants can be left in place for a long period. To increase your supply of plants, take root cuttings in fall. The plant self-sows readily; remove seedlings if you don't want them or if they do not grow or bloom true to the parent.

David Cavagnaro
Salvia x superba

• Zones 2-10, 14-24, 31-41
• Full sun
• Regular watering

One of the most reliable of the hundreds of salvias grown for the garden, Salvia superba lends vivid purple-blue shades to the garden throughout summer and into fall. The 1/2-inch flowers are carried on 1 1/2- to 3-foot-tall spikes that rise from clumps of gray-green, 1- to 3-inch, elongated oval leaves with the distinctive sage fragrance common to many salvias.

Among the many available cultivars, two outstanding choices are 'May Night', a compact plant (to 1 1/2 feet high and wide) with deep purple-blue flowers, and 'Blue Hill', also with deep purple-blue flowers but reaching nearly 2 1/2 feet tall and wide.

This salvia grows well in ordinary soil but appreciates soil amended with organic matter. It tolerates some dryness but prefers regular water. To prolong bloom, cut spent flower spikes to the ground. Divide every 4 to 5 years, when clumps become too large or die out in the center.

Michael S. Thompson
Sedum 'Autumn Joy'

• Zones 1-24, 29-43
• Full sun or partial shade
• Moderate to little watering

This plant is a deservedly popular for the year-round interest it brings to the garden. It starts the growing season with fresh green foliage. Dense, dome-shaped, 6-inch-wide clusters of pale pink flowers appear in late summer; in autumn, they turn coppery pink, then rosy rust. The spent flower heads can be left in place for winter decoration and cut back when new growth emerges in spring.

Upright or slightly spreading stems reach 1 1/2 feet tall and are evenly covered with 3-inch, roundish, slightly succulent leaves in pale blue green. Flowers appear at the stem tips.

This plant grows best with full sun and fairly dry soil, but it will also take partial shade and some additional water. Clumps gradually increase in size to 2 feet across; divide them every 2 to 3 years, or center stalks will begin to dry up and fall off when flower clusters emerge.

Jerry Pavia
Chrysanthemum superbum

• Zones 1-24, 26 (Northern part), 28-43
• Full sun; partial shade in hot-summer climates
• Regular watering

Botanists have changed this plant's name several times over the years; at one point it was removed from Chrysanthemum and reclassified as Leucanthemum (catalogs may still offer it as such). By any name, though, the yellow-centered white daisies look splendid both outdoors in the garden and indoors in bouquets. With routine care, plants will bloom happily from early summer through midfall.

The 3- to 5-inch-wide, single or double flowers are borne individually on leafy stems rising from basal mounds of coarsely toothed, dark green foliage. They're long lasting--in some cultivars, an individual flower may persist up to several weeks. The most popular cultivars grow 2 to 3 feet high and 1 1/2 to 2 feet wide; some of the newer ones are especially heavy blooming.

Shasta daisies prefer fairly rich, moist soil, though some do well in regular garden soil. In all soils, good drainage is important, especially in winter. During the growing season, fertilize regularly to increase the number of emerging flower stalks; cut spent stalks back to the ground after flowers fade. In cold-winter areas, mulch around clumps' bases in fall; don't cover remaining foliage, though. Divide every 2 to 3 years; replant new growth from the edge of each clump and throw away the woody center.

Shasta daisy gall disease causes the root crown to split into many weak, poorly growing plants that quickly die. Dig out affected plants and do not replant new ones in the same spot.

Jerry Pavia
Coreopsis verticillata

• Zones 1-24, 26, 28-45
• Full sun
• Moderate to little watering

Threadleaf coreopsis blooms abundantly all summer long, carrying its daisylike, 1- to 2-inch, yellow flowers above clumps of ferny, feathery foliage. Blossoms are borne so thickly that you can't deadhead individually, so just cut back the multistemmed branches with shears; they'll soon regrow to bloom again.

This plant isn't fussy about soil, but good drainage is important. It is somewhat drought tolerant. Divide clumps every 1 to 3 years — in fall in warm-winter climates, in spring where winters are harsh.

C. v. 'Moonbeam' is a favorite; it forms a fluffy mound to 3 feet tall and wide, covered with pale yellow flowers.

Michael S. Thompson
Veronica spicata 'Red Fox'

• Zones 1-9, 14-21, 38, 41-43
• Full sun
• Regular watering

Veronica spicata is just one of the hundreds of Veronica species — commonly known as speedwells — offered in nurseries and catalogs. In summer, its rounded clumps of small (to 1 1/2-inch), green, oblong leaves send up candlelike blossom spikes 15 to 20 inches tall, densely packed with tiny (1/4- to 1/2-inch) flowers. Blossoms are tubular, flaring out to four or five lobes. Cultivars include blue-flowered 'Blue Fox', 'Red Fox' (deep rosy red blooms), and 'Icicle' (white blossoms, gray-green leaves).

Give regular water. Well-drained soil is important, especially in Southern gardens. This is one plant that thrives on frequent division; plan to divide clumps every 2 years for best growth and bloom.

Cynthia Woodyard
Achillea

• Zones 1-24, 26, 28-45
• Full sun
• Moderate watering; needs less once established

Among the perennials that flower in summer and early fall, yarrow is among the most carefree and heavy blooming. Enjoy the blossoms outdoors in the garden or indoors as cut flowers; you can even dry them for use in winter bouquets.

The large, flat-topped flower clusters rise on 1 1/2- to 3-foot stalks from clumps of lower-growing foliage. Colors range from white to pastel shades to paprika red, but the familiar yellow yarrows are still favorites. Plants grow well in ordinary soil and with only moderate water; in fact, they may languish if soil is too rich or too moist. Divide when clumps get too crowded.