Lily: Hardy Perennial Bulbs
How to Plant
Planting in the Garden:
- Success with bulbs depends on good soil preparation. Select a site in full sun to light shade with good drainage where water does not stand on the surface after a rain event. Lilies thrive in well-drained, moist soils. Avoid siting lilies where they will be exposed to extreme heat.
- Dig the soil to the depth of a spade blade (about 10 inches). Work in organic matter to improve drainage, and at the same time improve the ability of the soil to retain moisture. A moderate amount of a balanced fertilizer such as Bulb-tone may be incorporated into the soil at this time.
- Plant so the top of the bulb is 2 inches below the soil line. Space bulbs 6-16 inches apart, depending on the variety. Plant the flat part of the bulb down and the pointed part up.
- 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.
- Water thoroughly at least once a week to help new roots grow down deeply. Soil should be damp at about 1 inch below the soil surface. You can check this by sticking your finger in the soil. Water early in the morning to give all leaves enough time to dry. One inch of rain or watering per week is recommended for most perennial plants. You can check to see if you need to add water by using a rain gauge.
- Some taller lilies may require staking to prevent them from falling over in the wind.
- Deadhead after blooming.
- Cut back stems to the base after the first frost in fall.
- Divide in fall when plants become overcrowded.
- 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.
- Lilies may be cut for cut flowers when the buds are colored and swollen but not yet open. When cutting for cut flowers, never remove more than one third of the plant.
- Be sure to site fragrant lilies when you will enjoy the fragrance often, such as below a window or along a walkway.
Common Disease Problems
Basal Rot: This fungus invades the bulb through the roots and basal plate. It causes premature streaky yellowing of the foliage and the basal plate is dark brown and dead and the scales fall off. It is more prevalent in warm, moist soils. Burpee Recommends: Avoid overwatering in warm months and provide good drainage. Contact your Cooperative Extension Service for recommendations.
Blue Mold: Bruising or mechanical injury can cause a blue mold to form on the injured part of the bulb. This is harmless to the bulb. Burpee Recommends: Carefully washed off the bulb prior to planting. Dust with a fungicide recommended by your Cooperative Extension Service.
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Leaf Scorch: Semicircular brown areas develop along leaf margins. It is most severe in high acid soils with low nutrients. Burpee Recommends: Lilies prefer a soil pH of 6.5 – 7.0, raise your pH if it is not lower than 6.0. Provide adequate fertilization, especially nitrogen and calcium.
Virus Diseases: Lilies can get virus diseases mostly spread by aphids. They cause irregular mottling on the leaves and color breaks in the flowers and leaves. The bulb scale may have brown ring patterns. Burpee Recommends: Control aphids which spread the diseases. Remove and destroy infected plants. Avoid planting near alternate hosts such as tulips.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects that 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 who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Lily Leaf Beetles: The larvae and adult beetles feed on lily leaves. The larva is a yellow grub with a dark head and the adult is ¼ inch long, bright scarlet with black legs and antennae. They lay eggs on the undersides of the leaves. Burpee Recommends: Check with your Cooperative Extension Service for pest controls.
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.
Spider mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.
Can lilies be used as cut flowers? Yes, they make great cut flowers.
Are lilies the same as daylilies? No, lilies are in the genus Lilium and daylilies are in the genus Hemerocallis. True lilies are bulbs which daylilies are perennials with fleshy roots. The flowers of daylilies only last one day while lily flowers last several days.
Are lilies deer resistant? No, deer will eat your lilies.
Are all lilies fragrant? Some are, some are not. Asiatic lilies tend to not be fragrant, while Oriental lilies have a strong scent.
Can I plant lilies in a container? Yes you can plant shorter varieties in containers. Taller varieties tend to be more challenging to grow in containers.