Hostas (Hosta spp., USDA zones 3-9) are some of the most popular plants for home gardens and landscapes. They are easy to grow and provide a range of leaf colors, leaf shapes and textures not found in other plants. Flourishing in a shade garden, this cold-hardy perennial will come back season after season for decades. The species H. plantaginea is one of about 45 registered hosta species. Other popular species include H. sieboldiana, H. ventricosa, and H. fortunei. There are more than 6,000 cultivars in the Hosta genus.
The flowers of some cultivars produce a fragrant, honeysuckle-type scent, which is a trait not found in all cultivars. The flowers are 3- to 6-inch-long trumpet-shaped blooms that blossom in late summer on 30-inch-tall stems. Hosta flowers come in shades of white, lavender, violet, and even purple-and-white streaked patterns.
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Most hosta species originated in China, but they've been grown in this country since the late 18th century. These shade-tolerant plants prefer morning sun followed by afternoon shade, but some cultivars are more sun-tolerant than others. Popular sun-tolerant cultivars include Hosta 'August Moon,' Hosta 'Sum and Substance' and Hosta 'Guacamole.'
Plants range in size from just a few inches tall and wide to 3- to 4-foot-tall specimens that can spread up to 8 feet or more. Leaves can be broad or narrow, with shades of green and pronounced veins, producing a rich, textured surface. Some cultivars have variegated coloring. Hostas are hardy, but they do have a few pests that can harm them. If deer often visit your yard, they will treat your hostas like an all-you-can-eat salad bar.
Best Uses for Hostas
Because of the variety of sizes and leaf colors, hostas can fit anywhere a shade-tolerant plant likes. Common sites include shady areas like borders, patio gardens, foundations and rock gardens. Planting them beneath shade trees is a good way to fill out the garden, but hostas do need some light. A few hours in the morning is best. You can also grow them in pots and place them on the patio or deck. Just remember that they require some shade in order to thrive.
They look best when a number of plants are massed together. Choose cultivars with different leaf colors, patterns, and textures to create a stunning effect. The leaves from massed plantings shade the ground below them, discouraging weed growth. Many hostas have large leaves that create a dense texture in the garden, so consider combining them with ferns and other plants with fine textures. The contrast will loosen up the look of the garden.
How to Grow Hostas
- Common Name: Hosta
- Botanical Name: Hosta spp.
- When to Plant: From spring into the summer but at least 30 days before the first frost
- USDA Zones: 3-9
- Sun Exposure: Partial sun
- Soil Type: Fertile soil that drains well and is slightly acidic
- When It's in Trouble: Brown spots could be a sign of a fungus due to poor air circulation. Holes in plants are a sign of slugs.
- When It's Thriving: Produces bushy, healthy-looking leaves
Starting Hostas From Seed
Most hostas start out in the garden as bare-root stock or potted plants. Although it is tricky, you can grow them from seed either by buying seeds or harvesting the seed pods from plants that are already in your garden.
If you go the harvesting route, be aware that hosta cultivars don't come true from seed, which means that the plant you grow will not look like the plant from which you harvested the seeds. An exception is Hosta ventricosa, which reliably comes true from seed. Some hosta seeds have low germination rates, so it is best to start with many seeds because some of them will not germinate.
Ripe seed pods turn brown or black, and the pod begins to split open about four to eight weeks after the plant blooms. Harvest the pods and remove the seed kernels from the pods. Allow the seeds to dry out and then place them in plastic bags and store them in the refrigerator for about four weeks. This fools the seeds into thinking they are going through the winter dormant cycle and will help with germination. As an option, you can sow the seeds outside in late summer to fall, which gives them a "natural" cold treatment during winter.
If sowing seeds indoors, you can use seed-starter trays with humidity domes. The trays should contain a starter mix. The seeds do not need light to germinate, but they must be kept warm with moist soil. Germination can take up to three weeks. A single leaf means that germination has started. Once two leaves are produced, you will need to remove the humidity dome and place the plants under grow lights set a few inches above the plant. Keep them under the light for 18 hours per day.
As the plants grow, cull the weak plants and transplant the healthy ones to larger pots. Introduce healthy plants to the outside gradually in a process called hardening off. Seeds started during the winter should be ready for the garden by the following spring or summer. You can keep the seedlings in pots placed outside in a shady location throughout their first summer. Then, transplant to the garden in September.
Starting Hostas From Seedlings
Most gardeners start their hosta plantings with young, potted plants. Choose a spot that gets morning sun but is protected in the afternoon with shade. Prepare the planting area by turning over the soil to a depth of about 12 inches. Add organic matter, such as compost or leaf mold.
Dig a hole that is as deep as the root ball and about twice the width of the root ball. Unpot the plant and untangle the roots by raking the roots with your fingers. Place the plant in the hole and backfill with the soil you removed. The top of the root ball should be even with the surrounding soil. Be sure not to bury the crown, or your plant may rot.
Gently tamp the soil around the plant to eliminate air pockets. Water thoroughly and apply 2 or 3 inches of mulch around the base of the plant but don't let the mulch touch the main stem. Consult the plant tag for spacing recommendations, usually 1 to 3 feet unless you're growing a very large cultivar.
In What Zone Do Hostas Grow Best?
The majority of hostas can grow as perennials in USDA plant hardiness zones 3 through 9. Hostas are shade-tolerant plants, but they can take an ample amount of direct sun in cooler climates provided that they have sufficient water. Plants with gold coloring need sunlight in order for the color to develop.
In warmer climates, they need shade in the afternoon. A few hours of morning sun followed by afternoon shade is best, especially in warm areas. Plants that receive full sun in hot climates develop leaves whose edges turn papery and brown.
When Should You Plant Hostas?
Hostas are easy to grow, and they are adaptable. Spring is the best time to plant them, but you can plant into the summer as long as you keep them well-watered. Try to plant on a cloudy day because it eases transplant shock. If you do plan on planting late in the summer, give the plants enough time to establish their roots before the cold weather. Plant hostas at least 30 days or more before the first frost date.
Soil, Sunlight and Water Recommendations for Hostas
Hostas like fertile soil that drains well and has a pH of 6.5 to 7.5. A soil's pH is a measure of its acidity and alkalinity on a scale that runs from 1 to 14 with a pH of 7 considered neutral. Before planting, determine the soil's pH as well as the nutrients it contains or may be lacking by having it tested at a garden center or your county's extension office.
The test results will determine what soil amendments you may need. You can work organic matter into the soil, such as compost or leaf mold, to add nutrients, loosen the soil, and promote drainage. For ongoing care, apply a balanced, slow-release fertilizer in the spring. Keep granular fertilizer away from the foliage and the plant's crown because too much fertilizer can cause burns.
Most hostas prefer dappled shade rather than full shade. The ideal conditions include morning sun and afternoon shade to protect the plant. In very warm climates, afternoon shade is essential.
Keep the soil moist but not sopping wet around new plants. Hostas require about 1 inch of water per week, so supplement rainfall with manual watering where necessary.
How to Propagate Hostas
Hostas can be divided every three to five years. Unlike many other perennials, it isn't necessary to divide hostas for the health of the plant, but dividing the plants creates new plants, and it can tidy up the garden by relieving overcrowding. It is best to divide mature plants in the spring just as the plants begin to show signs of growth.
Dig around the plant and remove as much of the root system as possible. Shake the soil from around the roots or dip them in a bucket of clean water. This will help you see the root system clearly. Use a clean, sharp garden knife to divide the plant into two or three sections. Each division should include a healthy portion of roots and the growing stems, called eyes. Cut away any dead parts of the plant. Replant one clump in the original location and the others in other parts of the garden.
How to Winterize Hostas
Hostas will die back and flatten out after a hard frost. To prevent disease and insect infestation, cut the stalks back to ground level. Remove all debris from the area and add a layer of compost to the garden.
Common Pests and Other Problems for Hostas
Deer love hostas. They will eat the plants right to the ground. They will trample other plants that they may not care for just to get to the hostas. There are spray-on and granular deer deterrents available. If you use one, follow the directions carefully. Repeated applications are usually necessary, especially after a rain.
Another option is to fence in the garden, but some deer can jump as high as 8 feet. Solid fencing is more of a deterrent than fencing through which the deer can see. They don't like jumping into an area they can't see.
Slugs and rabbits also feed on hostas. Slugs tend to feed at night, but they leave a slime trail behind them that reveals their presence. There are rabbit deterrents available as well as traps and many homemade deterrents for slugs. There is also the old trick of placing a steep-sided bowl in a hole and filling the bowl with beer. Slugs crawl into the bowl and drown. You dispose of them in the morning.
Aphids may also feed on hosta leaves. They can leave a sticky residue that attracts ants. Natural predators, such as lady beetles, can help get rid of the pests. You can also remove aphids with insecticidal soap.
Common Diseases for Hostas
Anthracnose is caused by a fungus that forms brown spots on the leaves of the plant. The disease can lead to extensive damage, but it seldom kills the plant. Anthracnose can be prevented by maintaining good air circulation among hosta plants and avoiding overhead watering since it can spread the disease. Remove damaged leaves and clean up garden debris. A fungicide formulated for the purpose can be preventatively used for extensive outbreaks.
Sooty mold forms on the honeydew excreted by aphids and other insects. This often occurs when the hosta is planted under another plant or tree where the aphids are feeding. If the mold accumulates, it can harm the plant. It can be removed from the plant's leaves with a soft, moist rag. Control aphids on surrounding plants to prevent damage to the hostas.