Learn About Hostas
How to Sow
Planting in the Garden:
- Select a location in full shade to part shade with good rich moist organic soil. Hostas prefer afternoon shade and protection from strong winds.
- Prepare the bed by turning the soil under to a depth of 6-12, inches removing any debris, and lightly raking as level as possible.
- The addition of organic matter (leaf mold, compost, well-rotted manure) benefits all gardens and is essential in recently constructed neighborhoods.
- Plant on a cloudy day or in late afternoon to reduce transplant shock.
- Dig a hole for each plant large enough to amply accommodate the root ball.
- Unpot the plant and gently loosen the root ball with your hands to encourage good root growth.
- Place the top of the root ball even with the level of the surrounding soil. Fill with soil to the top of the root ball. Press soil down firmly with your hand.
- Use the plant tag as a location marker.
- Thoroughly water and apply a light mulch layer on top of the soil (1-2 inches) to conserve water and reduce weeds.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their germination.
- Mulches also help retain soil moisture and maintain even soil temperatures. For perennials, an organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
- Careful watering is essential in getting perennials off to a good start. Water enough to keep the soil evenly moist. Plants are remarkable drought resistant.
- Good air movement is also important.
- After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer, as higher rates may encourage root rots.
- Some people remove the flower stalks as the plant is grown primarily for the foliage. If you do keep the flowers, cut the stalks after flowers fade unless you would like them to self-sow.
- In colder regions, apply another layer of mulch (1-2 inches) after the ground freezes in fall. Evergreen boughs (from Christmas trees) provide additional protection. Remove this mulch in the spring.
- Divide when plants become overcrowded, every 3-5 years. In general, divide in spring or fall when plants are dormant. Dig clumps from the ground and with a sharp knife or spade, cut into good sized divisions, each with several growing eyes and plenty of roots. Remove any dead or unhealthy plant parts and cut back stems. Replant one division where the plant was originally and plant the extra divisions elsewhere in your garden or give them away to gardening friends. Plant the divisions immediately, or as soon as possible, and water well.
- Hostas are extremely tough and low maintenance as long as they are in the proper environment.
- Hostas combine nicely with most shade loving plants. Plant with bleeding hearts, hellebores, heucheras and epimediums. Plant daffodils and other hardy spring bulbs around hosta clumps; as the hosta foliage emerges it will hide the ripening bulb foliage. They also make a great ground cover or specimen plant.
- Hosta foliage makes an attractive addition to fresh flower arrangements.
Common Pests and Problems
Common Disease Problems
Anthracnose: This fungus attacks the foliage of hosta. It causes irregularly shaped white to tan spots with brown borders. In time the spots lose their centers and the leaves become tattered and torn. The fungus overwinters in diseased plant debris. Burpee Recommends: Provide sufficient space between plants for good air circulation, avoid overhead watering which can spread the fungus spores, keep a clean garden, remove and discard all diseased plant material. Use a mulch to prevent spores from splashing from the soil onto plants.
Hosta Leaf Nematodes: These are microscopic worms that live under the tissue of the leaves. In late June there is a yellow discoloration and affected areas develop into dark brown streaks or wedges bordered by leaf veins. The brown streak may be seen from both sides of the leaves. Burpee Recommends: These are microscopic so you cannot see them and the damage may look like a foliar fungus. To see if you have nematodes, cut open the leaves with symptoms. Put some water on a clear glass plate to act as a petri dish. Leave the cut section of the leaf in the water 10-30 minutes, then back light it (hold it over a light from behind) and you will see tiny nematodes swimming out of the leaf tissue. If you have them, remove plants and destroy them. Check plants in a six foot radius for symptoms. Avoid overhead watering. Nematodes live in the plants, not the soil, so removing plants will remove the nematodes.
Root Rots: A number of pathogens cause root rots. Burpee Recommends: Pull up and discard infected plants. Make sure your soil has excellent drainage. Contact your Cooperative Extension Service for recommendations.
Sooty Mold: This is caused by a mold that grows on the honeydew excreted by aphids and other sucking insects. It is common on hosta as the insects may be feeding on the trees or taller plants nearby that are providing shade for the hosts. Burpee Recommends: Control taller plants for aphids or scale. Wash off the surface of the hosta leaves with soapy water. The damage is cosmetic only.
Virus (Various causes): The most characteristic sign of virus is tight and dark green mottling of the leaves. Young leaves may be bunched or lumpy, twisted or otherwise distorted. Plants become stunted. Burpee Recommends: Remove and destroy infected plants.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Cutworms: These insects cut off the seedlings at the soil level. Burpee Recommends: Place a paper cup collar (use a coffee cup with the bottom cut out) around the base of the plant. They are usually mostly a problem with young seedlings. You can also control by handpicking and controlling weeds, where they lay their eggs.
Deer: Eat the hostas to the ground. Burpee Recommends: Try a deer repellent or physical barrier for young plants.
Rabbits: Chew on plant leaves. Damage is similar to deer damage but not usually as extensive. Burpee Recommends: Use a hot pepper wax spray or rabbit repellent.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
What is eating my hosta plant? There are many possibilities, but the most common are deer or slugs. Check for slugs at night. If it is eaten to the ground it is probably deer.
When is the best time to divide my hosta? The best time is to divide in late summer or early fall. They can be divided any time, except in hot dry weather conditions.
Can hostas be planted in the sun? No, planting them in the sun will cause leaf burn. They perform best in the shade.
Can I use hosta as cut flowers? Yes, and the foliage also makes a nice addition to an arrangement offering different shades of green and texture to the arrangement.
Can I grow hosta in a container? Yes hostas are great for containers, especially the smaller varieties. Use a commercial planting mix rather than garden soil, and be sure they have adequate moisture.