How to Grow and Care for Hostas

Hostas (Hosta spp.) are a popular garden plant for very simple reasons. Hostas don't need sun; they thrive in shade and part-shade, unlike many other plants. And hostas are extremely easy to care for and propagate. Plus, as perennials, hostas come back every year with proper care. You can even grow hostas in pots.

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 can take five to seven years. There's also a wide range of sizes, from mini to mammoth.

Hostas can be planted in early spring or as soon as the heat of summer ends in early fall. Note that hostas are toxic to pets, so be mindful about where you plant them.

Hosta Care

Hostas are normally planted as potted transplants or bare root divisions. They are commonly considered shade plants; however, hostas need some sun to thrive. Gold-leaf varieties actually need some sun to develop their rich color. But you should not plant hostas in perpetually hot, sunny areas. Morning sun with afternoon shade is ideal for those varieties that tolerate higher amounts of sun.

Hostas in winter need a minimum of six weeks of temperatures 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 hostas in 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.

Planting and Soil

Plant hostas roughly 1 to 5 feet apart, depending on mature size, and loosen the soil around a foot deep. Nursery plants should be planted at the same depth they were in their container--the top of the root ball should be flush with the ground level. You can start planting in the early spring once the ground has thawed. Or plant at least 30 days prior to your first frost in the fall.

Hostas are tolerant of most types of soil, provided that the soil is well-drained. But you should not plant hostas in clay soil, which holds too much moisture. They also like their soil to be rich and full of organic matter with an acidic soil pH. For hostas in pots, use a standard commercial potting soil that is well-drained.

Light

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 to enhance the yellow coloring. Check the specific light requirements of your hosta variety. If the leaves develop brown tips, faded areas, or dull color, the plant might be getting too much sun.

Water

Water hostas as needed to keep the soil moist but not wet. Once established, hostas will tolerate occasionally dry soil, but they won't survive long periods of drought. Deeper, infrequent watering is better than frequent shallow applications. When growing hostas in pots 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.

Fertilizer

Proper feeding is one way to make hostas grow bigger. 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 pots is a bit more involved because 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 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 Hostas

Hostas are low-growing, clump-forming perennial plants grown mostly for their lovely foliage. But beyond this, a single description is almost impossible, as 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 hosta plants 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

Fall and Winter Hosta Care

To care for hostas in the fall, keep watering but pull back on fertilizing. The foliage will naturally start to die back. At that point, it's best to cut the plants to the ground to prevent pests or diseases from infesting the depreciating foliage. Hostas in winter are overall hardy and survive just fine. But in cooler climates, it can help to add a layer of dry mulch over the roots to insulate them. Hostas in pots that will remain outdoors for the winter are best buried in the garden up to the rim of their containers and then covered with mulch.

Pruning

Some gardeners clip off the flower stalks when they appear, though other 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.

Propagating Hostas

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 divide. A very small piece of root is all it takes to create a new plant. Here's how to do it:

1. In fall or early spring, use a sharp shovel or spade to dig up the entire plant, freeing it from the soil.
2. 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.
3. 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, might produce offspring with plain green leaves.

But plant enthusiasts might still want to try this exercise, and it's not hard to do. After the flowers have faded, pick off the mature 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 and 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 in pots filled with ordinary commercial potting mix can grow quite well. There are no special potting requirements, but the container should be at least as wide as the mature plant's foliage spread and have drainage holes. Remember that container plants are subject to temperature extremes, so you might 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 hostas in pots 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. Transplanting hostas might be necessary as the plant spreads over time, but many varieties can remain in the same pot for many years.

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.
• Deer and rabbits love hosta leaves. Plant them where they won't be snacks for them, or consider using a commercial repellent on your plants.
• 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 might 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 Hostas 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 hosta 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 Hostas

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.

Shredded Leaves

Hail storms can severely damage hosta leaves, which sometimes leads to disease problems. Affected leaves should be removed, and the plant should 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.