In their native habitat of Chile and Argentina, wild stands of Peruvian lilies grow and spread into large colonies. Where Peruvian lilies are hardy and well-tended in the landscape, the plants can spread vigorously. Treat them as pass along plants, and dig and share tubers with friends. You can also control their spread by cutting the flowers for the vase with abandon, which will prevent seeding. Peruvian lilies are remarkably free of serious pests and diseases, though they can be affected by some of the usual garden thugs, including slugs, mites, and aphids. Use insect soap or slug bait as needed to prevent damage.
Light
Peruvian lilies flower most abundantly in full sun (six to eight hours), but in very hot climates, they will appreciate some shade during the peak of the afternoon sun.
Soil
Peruvian lilies like fertile, well-drained soil. You can accomplish both of these qualities by improving your soil with an organic amendment, like compost or leaf mold. These plants do well in most ordinary garden soil, though they prefer a slightly acidic pH (5.5-6.5). Peruvian lilies grow well in raised beds or by using the lasagna gardening method.
Water
Peruvian lilies need regular moisture, especially as summer temperatures heat up. Give them at least 1 inch of water per week, or when the soil surface feels dry.
Temperature and Humidity
Alstroemeria likes temperatures in the 65 to 80 degrees Fahrenheit range. Temperatures in the upper 90s can cause the plants to produce blind stems—foliage without flowers. You can prevent these blind stems by planting tubers in partial shade, or in an area that receives only morning sun. In humid areas, it’s important to provide adequate spacing to help air circulation that will carry away spores of fungal diseases like botrytis.
Fertilizer
One feeding in early spring will prep your Alstroemeria for the growing season. Use a balanced flower fertilizer. A steady stream of nutrition will keep your Peruvian lilies productive in the garden. You can also provide fertility via a mixture of organic additives like manure and compost tea.
Types of Peruvian Lily
Peruvian lily breeders focus on introducing exciting new colors for the cut flower market, which you can also use to enhance your garden design. Here are a few favorites among many options:
‘Fougere’ has large white flowers with purple flushes in the throat, streaked with burgundy. It grows 24 to 36 inches tall.‘Moulin Rouge’ has cheerful orange and yellow tones that glow in the summer border as well as the bouquet. It tops out at about 28 inches tall.‘Mauve Majesty’ has bright mauve-pink flowers with creamy yellow throats. It is a relatively tall variety, growing to around 30 inches’Indian Summer’ has coppery orange flowers and grows up to 30 inches tall.‘Princess Eliane’ has bright pink flowers with yellow and burgundy throats. It is a small variety, 9 to 12 inches tall.
Pruning
Cut Peruvian lilies back after blooming to prevent the plants from directing energy into seed production. Where plants are spread too much, pull up stems that are less productive to encourage younger plants from newly formed tubers to flourish.
Propagating Peruvian Lily
Peruvian lily can be propagated in several ways, but the easiest and most reliable method is by dividing the tuberous roots. The best time to propagate Peruvian lilies is by dividing tubers in early spring before new growth begins. Here’s how:
Growing Peruvian Lily From Seed
Growing these plants from seed is not a common exercise, since the germination rates are low and the seeds require special handling. And it can take several years for seed-grown plants to achieve flowering maturity. Seed propagation of Peruvian lily is a practice for very serious gardeners only. Make sure to plant plenty of seeds, as many will fail to germinate. If you do want to try seed propagation, you can collect the seed pods after the flowers fade, then dry them until they are brittle and hard. Break apart the seed pods and harvest the seeds. Sow seeds 1/4 inch deep in sterile potting mix, then place the container in a cold location (about 40 degrees Fahrenheit) for about one month. This cold stratification is necessary for the seeds to germinate and sprout. After the cold treatment, place the containers in a 70-degree location with bright indirect light until the seedlings have developed their true leaves. Then, move the container into a location with full sun to grow them into mature plants. The seedlings are ready to plant in the garden after two sets of true leaves have formed. Take care when transplanting from pots, as these plants do not like to have their roots disturbed when they are young. Place seedlings in the garden spaced 8 inches apart. Be prepared to wait for two years or even longer for the plants to flower.
Potting and Repotting
Your Peruvian lily plants can thrive in large containers, and for many gardeners this is the preferred method of growing them. Pair them with trailing plants that enjoy the same growing conditions, such as sweet potato vine, million bells, or love-lies-bleeding. Plants may need staking to remain upright in containers. Use any commercial potting mix for your Peruvian lilies, and select an ample size pot—at least 8 inches wide and 24 inches deep. In warmer climates where the Peruvian lilies will remain outside year-round, even larger pots are recommended. Any pot material will be fine, but make sure the container has good drainage. Peruvian lilies cannot be moved indoors to grow as houseplants, but in colder climates, you can bring pots indoors for winter and store them as dormant plants in a cool, dry location. Keep the soil very dry to avoid rot. Dig, divide, and replant the tubers at the end of winter; use fresh potting soil when replanting.
Overwintering
In warmer regions (zones 8 to 10) Peruvian lilies require no winter protection, other than clipping back foliage as it dies back. Zone 7 is a transitional zone, and here the plants should be covered over with dry mulch for the winter. Gardeners in colder zones sometimes grow Peruvian lilies by digging and storing the tubers for the winter. Dig up your garden plants in the fall before the ground freezes. Shake off the loose soil and place the tubers in a paper bag filled with peat moss and hang it in a dry, cool (35 to 41 degrees Fahrenheit) location for the winter. Replant in spring after the soil warms to at least 60 degrees.
Common Pests & Plant Diseases
Peruvian lilies can be plagued by aphids, spider mites and whiteflies. While these pests are not usually serious in themselves, their presence can indicate unfavorable conditions where some serious diseases can spread:
Botrytis (gray mold) appears as furry, gray-brown spores on the plant’s leaves and stems. This fungal disease is hard to cure, but you can prevent spread by spacing plants well apart to improve air circulation and watering at ground level rather than overhead spraying.Root rot is caused by various fungi, and announces its presence by leaves and stems that wilt and collapse even though the plants are getting enough water. Allowing soil to dry out can allow plants to recover, but serious rot will call for the plants to be removed and destroyed. Prevent root rot by amending soil so it drains well.
How to Get Peruvian Lily to Bloom
These are not difficult plants to grow, and they will normally bloom well if given adequate water and light, and especially fertilizer. Potted plants will bloom better if fed every two weeks with a balanced 6-6-6 fertilizer. It is fairly common for Peruvian lilies to stop blooming robustly after five or six years. When this happens, it’s best to lift and divide the root clumps and replant to create new plants.
Common Problems With Peruvian Lily
Peruvian lily is not known as a temperamental plant and is generally easy to grow. However, there are some common complaints that are generally easy to rectify.
Plants Won’t Stay Upright
These plants have profuse flowers and rather spindly stems, so it’s common for the plants to flop over. This is a common problem for species grown as cutting flowers, and it is easily handled by staking up the flower stems.
Stems and Leaves Wither, Even When Plants are Well-Watered
This is a classic sign of root rot, caused by various fungi. Most common in warm, wet weather, you can prevent root rot by making sure the soil is porous and well-drained.
Plants Have Stopped Flowering
It’s common for Peruvian lilies to gradually stop flowering as the tubers get old, even though the foliage continues to flourish. Normally this happens as plants reach five or six years of age. When this happens, it’s time to lift and divide the tuberous roots. Don’t worry about frequent harvesting; the more flowers you harvest, the more the plant will produce.