Hostas (Hosta spp.) 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 that 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 in a wide range of sizes. The foliage colors can vary from pale yellow to the deepest of blue-greens, with many variegated forms also available. Leaf shapes can be anything from long and sword-like to huge and round with corrugated textures.
Hostas produce blooms on long stalks that extend well above the clumping foliage in late spring or summer, but the foliage is the main attraction. Some gardeners clip off the flower stalks when they appear, although more savvy growers recognize the value of the white or purple flowers to bees and other pollinators.
Hosta varieties include fast-, medium-. and slow-growing plants. Smaller varieties tend to grow fastest and can reach their mature size in three to five years; larger types may take five to seven years. Hostas can be planted in early spring or as soon as the heat of summer ends in early fall. They can also be grown indoors with a little extra care.
|Botanical Name||Hosta spp.|
|Common Name||Hosta, plantain lily|
|Plant Type||Herbaceous perennial|
|Mature Size||6 to 48 inches tall, 10 inches to 6 feet wide|
|Sun Exposure||Full shade to part sun|
|Soil Type||Rich, fertile, well-drained|
|Soil pH||6.0 to 6.5|
|Flower Color||White, lavender, pink|
|Hardiness Zones||3 to 9 (USDA)|
|Native Area||China, Japan, Korea, Russia|
|Toxicity||Toxic to dogs, cats, horses|
Hostas are normally planted as potted transplants or bare root divisions. They are most often used in shade gardens, where their ornamental foliage brightens dim areas. They work very well in groups or in masses and are also good as background plants or specimens in shady borders or woodland gardens. Yellow-leaved varieties are somewhat more tolerant of sun, but no hostas will thrive in perpetually hot, sunny areas.
Hostas need a minimum of six weeks of weather below 42 degrees Fahrenheit to go dormant during the winter. Outdoors, this occurs naturally in most areas, but it's a notable challenge of growing hostas indoors. Indoor pots can be stored in a garage, basement, or crawlspace (even in refrigerator) to ensure dormancy. Temperatures must be between 33 and 41 degrees Fahrenheit so the plants do not freeze.
Hostas are true shade garden plants that can survive in full shade. However, many varieties grow best when they receive dappled sun for a few hours each day. When plants have green and yellow variegated leaves, exposure to morning sun helps enhance the yellow coloring. Check the specific light requirements of your hosta variety. If the leaves develop brown tips, they have faded areas, or their color is dull, the plant may be getting too much sun.
Hostas are tolerant of most types of soil, provided it is well-drained. They do not do well in clay soil, which holds too much moisture. They also like their soil rich and fertile, full of organic matter. For container plants, use a standard commercial potting soil that is well-drained.
Water hostas as needed to keep the soil moist but not wet. Once established, hostas will tolerate occasional dry soil, but they will not survive long periods of drought unless they are regularly watered. Watering is best done near the base of the plant, beneath the leaves, rather than overhead watering, which tends to attract slugs and snails. When growing hostas indoors, maintain a regular watering schedule to keep the soil moist.
Temperature and Humidity
Hostas are not fussy about temperature or humidity and can grow in a wide range of climates. It's best to plant them in a location that is protected from strong winds. Comfortable indoor temperatures are good for hosta houseplants.
Often the best and easiest way to feed hostas is by adding a healthy layer of compost to the soil in the spring. This feeds nutrients to the soil and helps promote the soil food web. You can also feed hostas with a well-balanced organic fertilizer, applied after planting or when plants begin to come up in spring. Be careful not to get fertilizer granules trapped in the leaves, which can burn them.
Fertilizing hostas in containers is a bit more involved, since the higher frequency of watering strips the soil of nutrients relatively quickly. Feed potted plants at the start of the growing season with a slow-release fertilizer. Feed biweekly (once every two weeks) with water-soluble fertilizer throughout the growing season. Stop feeding four months prior to the winter dormancy period to gradually harden off the plant.
Is Hosta Toxic?
All parts of the hosta plant are toxic to dogs, cats, and horses. These plants are not toxic to humans and are grown for food in parts of Asia.
Symptoms of Hosta Poisoning
Animals that ingest hosta leaves, flowers, or roots may experience decreased appetite, diarrhea, vomiting, bloating, and depression. Dogs may also suffer from twisting intestines, while cats that eat large quantities of the plant may experience heart abnormalities.
Varieties of Hosta
Growers generally categorize hostas by size:
- Miniature: plants that mature to less than 9 inches tall
- Small: plants that mature to 9 to 15 inches tall
- Medium: plant that mature to 16 to 21 inches tall
- Large: plants that mature to 22 to 29 inches tall
- Giant: plants that mature to 30-plus inches tall. Some currently grow as much as 48 inches in height.
Some of the favorite hosta varieties include:
- 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; grows 18 to 24 inches tall in clumps up to 3 feet wide
- H. sieboldiana 'Frances Williams': Large, puckered leaves 12 inches wide, dark green with light-green veining; grows 2 feet tall and up to 5 feet in spread
- H. 'Patriot': Medium-size green leaves with white margins; grows up to 18 inches tall with a 30-inch spread
- H. 'Sum and Substance': A huge hosta growing to 30 inches tall and 5 feet in spread; large leaves (15 by 20 inches) are heart-shaped, starting glossy yellow and gradually turning golden
- Hosta sieboldiana 'Elegans': Grows 30 inches tall with a 4-foot spread; large leaves (10 by 13 inches) are heart-shaped and have a corrugated texture and blue-green color
You can divide hosta 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; this works in containers as well. The plant propagates very easily, though it can take some hard work to divide the tough root clumps. Hosta can also be grown from seeds in pots.
Potting and Repotting Hostas
If desired, you can repot container-grown hostas at the start of the growing season in spring. This may be necessary as the plant spreads over time, but due to the lack of growth during the dormancy period, repotting often is not needed. There are no special potting requirements, but the container should be at least as wide as the mature plant's foliage spread.
Common Pests and Diseases
Hostas can fall prey to slugs and snails that chew ragged holes in the leaves and can kill the plants if left untreated. These pests can also be a problem indoors. Deer are other voracious feeders on hosta leaves (hopefully not indoors).
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.