Hostas (Hosta spp.) are America's most popular perennial garden plant for very simple reasons: They are one of the few plants that thrive in shade, and they are extremely easy to care for and propagate. Hosta is a clump-forming plant that grows from rhizomatous roots. It produces blooms on long stalks that extend well above the clumping foliage in late spring or summer, but the foliage is the main attraction. Among the hundreds of hosta cultivars, there are fast-, medium-. and slow-growing varieties. 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.
Hostas are toxic to dogs, cat, and horses, so take care to keep these animals away from the plants.
|Common Name||Hosta, plantain lily|
|Botanical Name||Hosta spp.|
|Plant Type||Herbaceous perennial|
|Mature Size||6—48 in. tall, 10 in.-6 ft. wide|
|Sun Exposure||Shade, partial|
|Soil Type||Rich, fertile, well-drained|
|Soil pH||Slightly acidic (6.0 to 6.5)|
|Flower Color||White, lavender, pink|
|Hardiness Zones||3 to 9 (USDA)|
|Native Area||Eastern Asia|
|Toxicity||Toxic to dogs, cats, horses|
Hostas are normally planted as potted transplants or bare root divisions. They are commonly considered shade plants, but hostas are more appropriately regarded as partial sun plants, as some light is necessary for them to thrive. 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 enter a dormancy phase and reset their growth cycle. Outdoors, this occurs naturally in most regions, but it's a notable challenge if you try to grow hostas indoors. Indoor pots can be stored in a garage, basement, or crawlspace (even in a refrigerator) for the winter to ensure dormancy. Temperatures must be between 33 and 41 degrees Fahrenheit so the plants do not freeze.
Hostas can survive in full shade, but most varieties grow best when they receive dappled sun for a few hours each day. When plants have green and yellow variegated leaves, exposure to the morning sun helps enhance the yellow coloring. Check the specific light requirements of your hosta variety. If the leaves develop brown tips, if they have faded areas, or if 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. Deeper, infrequent watering is better than frequent shallow applications.
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. Normal indoor temperatures are good for hosta houseplants, provided they are getting a cool period for winter dormancy.
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 into 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. But 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.
Types of Hosta
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 over 2,000 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.
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: plants 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 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 over 3 feet 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 18 to 24 inches tall and up to 5 feet in spread
- H. 'Patriot': medium-size green leaves with white margins; grows up to 18 inches tall and just over 2 feet wide
- H. 'Sum and Substance': a huge hosta growing up to 36 inches tall and up to 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 up to a 4-foot spread; large leaves (10 by 13 inches) are heart-shaped and have a corrugated texture and blue-green color
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. If you do allow the flowers to bloom, clip off the stalks after the flowers have faded.
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. Here's how to do it:
- In fall or early spring, use a sharp shovel or spade to dig up the entire plant, freeing it from the soil.
- Break the root ball into segments, using your hands, if possible, or use a trowel or shovel if the clump is too tough. Each segment should have some leaves attached, but even a small bare piece of root will usually survive and send up new shoots.
- Plant the pieces in the desired location. If you keep the pieces damp, they will keep for several weeks before replanting.
How to Grow Hostas From Seed
Many hostas are hybrids that do not "come true" if you collect and plant their seeds. Some varieties are entirely sterile and don't produce seeds at all. If you do collect and plant seeds from hybrid varieties, you should not be surprised if the resulting plants are different in appearance from the parent plant. Seeds from hybrid plants usually produce offspring that revert to the characteristics of one of the genetic ancestors. A hosta with variegated, ruffled leaves, for example, may produce offspring with plain green leaves.
But plant enthusiasts may still want to try this exercise, and it's not hard to do. After the flowers have faded, pick off the seed pods and let them dry for a few days before breaking them open and looking for the seeds inside. The seeds can be stored until midwinter, then sown in containers filled with commercial potting mix. Barely cover the seeds with additional potting mix, moisten them, and place them in a fairly warm, bright location. Mist the soil daily until the seeds germinate, which usually happens within about three weeks. Once the seeds sprout, place the plants in a slightly cooler location where they get indirect sunlight, and continue to grow them until it's time to plant them outside.
Potting and Repotting Hostas
Hostas grow quite well in containers filled with ordinary commercial potting mix. There are no special potting requirements, but the container should be at least as wide as the mature plant's foliage spread. Remember that container plants are subject to temperature extremes, so you may need to shelter outdoor pots in cold frames or an unheated garage (or dig them down into garden soil) for the winter in cold-weather regions.
If growing potted hostas indoors, give them a spot with bright indirect light and water them frequently—indoor winter air is usually quite dry. Remember that they will need a six-week chilling period at some point during the winter.
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 many varieties can remain in the same pot for many years.
These hardy plants usually require no special winter protection in most regions. As winter approaches, keep watering but pull back on fertilizing the plants. As the foliage dies back, remove it to prevent fungus spores and pest larvae from overwintering. It's best to discard the foliage rather than adding it to compost heaps. In far northern regions, it can help to mulch over the root crowns with a dry mulch, such as pine needles, straw, or dry leaves.
Potted hostas that will remain outdoors for the winter are best buried in the garden up to the rim of their containers, then covered with mulch.
Common Pests & Plant Diseases
Hostas are fairly low-maintenance plants, but there are a variety of pest and disease issues to watch for:
- Hostas can fall prey to slugs and snails that chew ragged holes in the leaves and can kill the plants if left untreated. A variety of baits are available to trap and kill these pests.
- Foliar nematodes can cause the leaves to brown between the veins. Affected plants are best removed and destroyed, as the chemical controls are extremely toxic to wildlife and fish.
- Several viruses are known to attack hostas; when stricken, afflicted plants must be removed and destroyed.
Anthracnose is one of the common fungal diseases affecting hostas, and one of the most serious. It is most common in warm, wet weather. Affected plants will show leaves with large irregular spots surrounded by dark borders. Fungicide spray preemptively applied in the spring may prevent the disease, but once it takes hold, plants usually need to be removed and destroyed.
Leaf spots and crown rot also occasionally are seen. Fungicides and good hygiene can help prevent these, but badly affected plants may need to be removed.
How to Get Hosta to Bloom
Most people grow hostas for the color and texture of their foliage, not their blooms. Many people even find the blooms unattractive and clip off the flower stalks before the blooms open. But hostas flowers do appeal to pollinators and they can offer a subtle, pleasant scent in the garden.
Basic care—just enough sunlight, ample water—is usually all that's needed to ensure that hostas flower. While these plants are known as shade plants, they do not flower much if planted in dense shade that receives no sunlight at all. Some varieties of hostas do not flower much until they are quite mature. Be patient; your variety could take as much as six or seven years before it blooms vigorously.
Common Problems With Hosta
Hostas are free of most serious problems, and those that do occur are usually cosmetic and rarely fatal. Here are some common problems noted with hostas:
Holes in Leaves
When you see ragged holes in leaves, you are usually witnessing the damage of slugs and snails. Keeping the ground area around plants free of debris will discourage these destructive mollusks.
Hail storms can severely damage hosta leaves, which sometimes leads to disease problems. Affected leaves should be removed and the plant will soon recover.
Leaf Edges Burned
Brown, shriveled edges on hosta leaves are usually caused by too much sun, which burns the leaves. Keep the plant well watered in the summer, and provide some shade if possible. Badly affected leaves can be trimmed away and discarded; new leaves will replace them.
Leaves Have Spots
This is usually a sign of some kind of fungal or bacterial disease. Prevent these diseases by giving good space between plants and watering with soaker hoses rather than overhead spraying.
Foliage Is Yellow, Growth Is Stunted
This is often a sign of crown rot; your plant is probably a victim of too much watering or rainfall. Badly affected plants will need to be removed and destroyed.
How can I use hostas in the landscape?
They are most often used in shade gardens, where their ornamental foliage brightens dim areas. Hostas work very well in groups or in masses and are also good as background plants or specimens in shady borders or woodland gardens. They can also make good potted plants and are sometimes even brought indoors as houseplants, though they require special care.
How long do hostas live?
Hosta is one of the longest-living of all perennials. There are many cases of plants living more than a century and outliving their owners.
Do deer eat hostas?
Although hostas are toxic to horses, they are anything but toxic to wild grazing animals, such as deer. Deer have been known to destroy an entire yard full of hostas overnight when they are hungry. The best prevention is fencing, or planting hostas among other plants that are known deer repellants, such as herbs, ferns, and daffodils.
Dividing Hostas Is a Great Way to Propagate New Plants. Oklahoma Gardening. Oklahoma State University.
Hostas. University of Minnesota Extension.
Hostas. University of Nebraska Lincoln Extension.