Hosta clausa
Common Name: hosta
Type: Herbaceous perennial
Family: Asparagaceae
Native Range: Korea
Zone: 3 to 8
Height: 1.00 to 2.50 feet
Spread: 1.00 to 1.50 feet
Bloom Time: August to September
Bloom Description: Purple
Sun: Part shade to full shade
Water: Medium
Maintenance: Low
Flower: Showy
Tolerate: Drought, Heavy Shade, Dry Soil, Black Walnut

Culture

Easily grown in average, medium moisture, well-drained soils in part shade to full shade. Tolerant of a wide range of soil conditions. Performs best in rich, moist, organic soils. Plants need consistent moisture during the growing season. Water is best applied directly to the soil beneath the leaves. Notwithstanding soil moisture preferences, this species reportedly has better tolerance for dryish soils than many of the hostas commonly grown in gardens today. Plants spread by stolons. Divide plants as needed in spring or autumn. Division is usually easiest in early spring before the leaves unfurl.

Noteworthy Characteristics

Hosta clausa is a medium sized hosta native to Korea. Foliage typically grows in a rounded clump to 12" tall and 12" wide. It is a sterile triploid that is noted for producing purple flower buds that do not open. Unopened buds eventually drop to the ground in fall without producing fruit. Shiny, narrow-oval to elliptic, medium to dark green leaves (to 6" long) have closely spaced veins and acute tips. Purple flower buds appear in late summer on scapes rising to 30" tall. Nakai 1930. Two different forms of this species merit mention: (1) Hosta clausa var. normalis produces open purple flowers, and (2) Hosta clausa var. stolonifera produces no flower scapes. W. George Schmid reports that the aforementioned varieties appear to be biologically the same as the species, but he retains the varietal names because the plants have historically been cultivated under such names and have over time remained stable.

Genus name honors Austrian botanist Nicholas Thomas Host (1761-1834) and was first established in 1812. The genus was subsequently renamed in 1817 as Funkia in honor of botanist Heinrich Christian Funk under the belief at that time that Hosta was an invalid name. Hosta was finally reinstated as the genus name in 1905 by the International Botanical Congress.

Specific epithet means closed bud and the Japanese name of this hosta, Tusbomi Giboshu, means closed flower.

Funkia remains a popular common name today in some areas. An additional common name for plants in this genus is plantain lily (foliage is somewhat plantain-like and flowers are somewhat lily-like in some species).

Problems

Slugs and snails are attracted to the foliage, chewing jagged holes in the leaves, and if left unchecked, can cause serious damage over a fairly short period of time. Leaf spots and crown rot are less frequent problems. Otherwise, hostas are virtually pest-free and are considered ideal low-maintenance garden perennials. Leaves, particularly of exposed plants, can be severely damaged by hail storms.

Garden Uses

Hostas are a mainstay of shade gardens. This hosta is effective in groups or massed. It is also effective as an edging plant. Mix with other perennials in shady borders, shade gardens or woodland gardens.