Hostas are America's most popular perennial garden plant for very simple reasons: Hostas are one of the few plants that thrive in shade, and they are extremely easy to care for and propagate. Unlike many perennials, which must be laboriously lifted and divided every few years, hostas are content to simply grow in place without much interference at all. If you do want to propagate them, hostas are among the very easiest of plants to split up and share with others. A very small piece of root is all it takes to create a new plant.
Hostas are low-growing, clump-forming perennial plants grown mostly for their lovely foliage, but beyond this, a single description is almost impossible, since there are hundreds of varieties available, ranging from those with tiny leaves about 1 inch in diameter growing in a 6-inch clump to giant specimens with leaves that are 18 inches long growing in clumps 6 feet across. Foliage colors range from pale yellow to the deepest of blue-greens, with many variegated forms also available. Leave shapes vary from long, sword-like leaves with ruffled edges to huge round leaves with rippled, corrugated textures.
Hostas are extremely popular because they grow so well in shady conditions where most landscape plant flounder. Hostas do flower, producing blooms on long stalks that extend up above the clumping foliage in late spring or summer, but the various varieties of yellow, green, or blue-green foliage in various shapes and sizes that are the real attraction. Some gardeners clip off the flower stalks when they appear, although more savvy gardeners recognize the value of the white or purple flowers to bees and other pollinators.
Hosta is a large genus that includes at least 45 species of clumping, herbaceous perennials that love shade and moist soil. When developed cultivars are included, there are hundreds of varieties available for landscape use. Some 3,000 named varieties are registered. The species are native to the woodland areas of Japan, Korea, China, and eastern Russia. Hostas are primarily known for their attractive foliage, which clump around a central crown.
The genus name derives from Austrian botanist Nicholas Thomas Host. The genus was renamed in 1817 as Funkia in honor of botanist Heinrich Christian Funk, but the original name was restored in 1905 by the International Botanical Congress. The name funkia is still used in some areas; another common name is plantain lily, coined because the leaves resemble those of the plantain.
There are hosta varieties hardy in USDA hardiness zones 3 to 9, making it one of the most versatile of all landscape plants. Not all varieties are hardy throughout this range, however.
Hostas are most often used in shade gardens, where the ornamental foliage brightens dim areas. Hostas work very well in groups or in masses, and they are also good as background plants or specimens in shady borders or woodland gardens. Yellow-leaves varieties are somewhat more tolerant of sun, but no hostas will thrive in perpetually hot, sunny areas.
Hostas are edible and are grown as food in parts of Asia. However, they are somewhat poisonous to dogs, cats, and horses, which may exhibit vomiting if they eat the leaves or flowers.
Hostas are normally planted as potted transplants. They prefer moist but well-drained soil in a shady or partial-shade location. They grow best in a location protected from strong winds. Once established, hostas will tolerate occasional dry soil, but they will not survive long periods of drought unless regularly watered. Watering is best done near the base of the plant, beneath the leaves, rather than overhead watering. Overhead watering tends to encourage feeding by slugs and snails.
When desired, you can divide the plants in early spring or in the fall by digging up the root ball, dividing it into small clumps of roots and leaves, and replanting. The plant propagates very easily, though it can take some hard work to divide the tough root clumps.
There are hundreds of varieties of hosta available for sale, and a large nursery may stock a dozen or more. Among the more popular varieties of recent years are:
- H. 'Blue Mouse Ears': A tiny hosta growing only 6 to 12 inches high with round, heart-shaped blue-green leaves.
- H. 'Golden Tiara': Light green leaves with yellow edging. Grows about 16 inches tall and 38 inches wide.
- H. tardiana 'Halcyon': Pale, spade-shaped leaves, gray-blue in color. Plants grow 18 to 24 inches tall in clumps up to 3 feet wide.
- H. sieboldiana 'Frances Williams': Large, puckered leaves 12-inch wide are dark green with light-green veining. Plants grow 2 feet high and up to 5 feet in spread.
- H. 'Patriot': Medium green leaves with white margins. Plants grow up to 18 inches high with a 30-inch spread.
- H. 'Sum and Substance': A huge hosta growing to 30 inches high and 5 feet in spread. Leaves are large (15 x 20 inches) and heart-shaped, with glossy yellow leaves that gradually turn golden.
- Hosta sieboldiana 'Elegans': Grows 30 inches tall with a 4-foot spread. The large (10 x 13-inch leaves are heart-shaped and have a corrugated texture and blue-green color.
Although very easy to grow, hostas can fall prey to slugs and snails that chew ragged holes in the leaves and can kill the plants if left untreated. Deer are also voracious feeders on hosta leaves.
Foliar nematodes can cause the leaves to brown between the veins. Leaf spots and crown rot also occasionally are seen. Several viruses are known to attack hostas; when stricken, afflicted plants must be removed and destroyed.
Hail storms can severely damage hosta leaves, leading to disease problems. Affected leaves should be removed; the plant will soon recover.