(Dwarf Wooly Yarrow, King Edward Yarrow)

Silvery-leaved, low-growing and drought tolerant, this is the perfect small yarrow for rock gardens and sunny border edges. A cross between the species Achillea clavennae and Achillea tomentosa, 'King Edward' forms a mat of narrow, gray-green, minutely toothed leaves. Loose, flattened clusters of buttery, pale primrose flowers bloom on short stems from late spring to midsummer. These are attractive to butterflies and have a soft, pretty appearance. Regular deadheading may extend...

(Monkshood, Sparks Monkshood)

A hybrid tuberous monkshood, 'Sparks Variety' is notable for its tall, thin stems bearing deeply lobed leaves and a terminal branched cluster of deep-violet flowers. Draped with a curious petal-like bract that resembles a hood, the eye-catching flowers give the plant its common name.

This perennial needs well-drained soil with uninterrupted moisture. It grows and flowers best in cool soil and partial sun but will tolerate full sun. The stems may need staking. Note that all parts of the plant...

(Carmichael's Monkshood)

Autumn flowered monkshood is a tuberous-rooted perennial originally from China and valued for its late season bloom. The leaves are produced in mounds and are delphinium-like, dark green, deeply dissected, toothed and have a leathery texture. Deep blue-violet flowers, each curiously shaped like a helmet or hood are produced atop leafy, tall, stately spikes in late summer and fall.

Plant monkshood in evenly moist but not wet soil. Full sun to partly shady locations are preferred. Monkshood grows...

(Carmichael's Monkshood)

Autumn flowered monkshood is a tuberous-rooted perennial originally from China and valued for its late season bloom. The Arendsii group hybrids are known for their compact, sturdy flower spikes, large leaves and azure-blue blooms. The leaves are produced in mounds and are delphinium-like, green, deeply dissected, toothed and have a leathery texture. Deep blue flowers, each curiously shaped like a helmet or hood are produced atop leafy, tall, stately spikes in late summer and fall.

Plant monkshood...

(Bicolored Monkshood, Monkshood)

With both handsome foliage and a wondrous display of blue, white or violet flowers in late summer or early fall, bicolored monkshood is a hybrid resulting from the cross of Aconitum napellus and Aconitum variegatum. The glossy leaves are produced in mounds and are dark-green, deeply dissected, toothed and have a leathery texture. Deep blue-violet and white flowers, each shaped like a helmet are produced in loose clusters atop leafy, tall spikes in late summer and fall.

Plant...

(Sweet Flag)

Calamus is an herbaceous perennial that is native throughout much of the United States and Canada. It has inconspicuous flowers and is grown primarily for its tall, upright, broad, iris-like foliage. One particularly attractive cultivar is 'Argenteostriatus', which has beautifully variegated leaves. These plants spread by rhizomes and grow best in moist boggy areas with full to partial sun. Semi-aquatic in nature, calamus works well in naturalistic plantings along waterways or in gardens with moist...

(Striped Sweet Flag, Sweet Flag)

Striped sweet flag, or striped calamus, is an herbaceous perennial that is native throughout much of the United States and Canada. It has inconspicuous flowers and is grown primarily for its tall, upright, iris-like foliage that is beautifully variegated with cream striations. These plants spread by rhizomes and grow best in moist boggy areas with full to partial sun. Semi-aquatic in nature, striped sweet flag works well in naturalistic plantings along waterways or in gardens with moist fertile soil.

(Striped Sweet Flag, Sweet Flag)

Striped sweet flag is an herbaceous perennial that is native throughout much of the Northern Hemisphere. It has inconspicuous flowers and is grown primarily for its tall, upright, broad, iris-like foliage. Acorus calmus 'Variegatus' has very showy white bordered leaves. These plants spread by rhizomes (underground stems) and grow best in moist boggy areas with full to partial sun. Semi-aquatic in nature, sweet flag works well in naturalistic plantings along waterways or in gardens with moist,...

(Grassleaf Sweet Flag)

Grassleaf sweet flag is a semi-evergreen perennial that originates from Japan. It is grown for its neat clumping habit and attractive grass-like foliage, which is aromatic when crushed. There are many highly desirable cultivars of sweet flag such as the golden variegated 'Golden Edge' and the dwarf 'Ogon'. This perennial is easy to grow if provided with rich evenly moist soil and full to partial sun. Plant in boggy gardens or in fertile beds and borders. These plants will not tolerate deep standing...

(Golden Edge Sweet Flag, Grassleaf Sweet Flag)

Golden edge sweet flag is an evergreen to semi-evergreen perennial that originates from Japan. It is admired for its neat clumping habit and attractive grass-like foliage that is aromatic when crushed. Its leaves are bright yellow with a narrow green stripe down the center of each blade.

This perennial is easy to grow if provided with rich, evenly moist soil and full to partial sun and looks great when mixed with other perennials for moist sites. Though well-suited to boggy gardens, plants will...