Peruvian Lily (Alstroemeria)

Lily-of-the-Incas, Parrot Lily, Peruvian Lily, Princess Lily

The cut flower of all cut flowers, alstroemeria (Alstroemeria sp.) is a staple flower for mixed bouquets. With blooms that can last up to two weeks and a color palette almost as wide as the spectrum, these perennial plants became a commodity for the flower markets and worked their way into home gardens.

I. Appearance and Characteristics 

Alstroemeria (), commonly called the Peruvian lily or lily of the Incas, is a genus of flowering plants in the family Alstroemeriaceae. They are all native to South America, although some have become naturalized in the United States, Mexico, Australia, New Zealand, Madeira and the Canary Islands. Almost all of the species are restricted to one of two distinct centers of diversity; one in central Chile, the other in eastern Brazil. Species of Alstroemeria from Chile are winter-growing plants, while those of Brazil are summer growing. All are long-lived perennials except A. graminea, a diminutive annual from the Atacama Desert of Chile.

Plants of this genus grow from a cluster of tubers. They send up fertile and sterile stems, the fertile stems of some species reaching 1.5 meters (4.9 feet) in height. The leaves are alternately arranged and supinated, twisted on the petioles so that the undersides face up. The leaves are variable in shape and the blades have smooth edges. The flowers are solitary or borne in umbels. The flower has six petals each up to 5 centimeters (2.0 inches) long. They come in many shades of red, orange, yellow, green, purple, pink, and white, flecked and striped and streaked with darker colors. There are six curving stamens. The stigma has three lobes. The fruit is a capsule with three valves. Alstroemeria are classified as an inferior monocot, meaning the petals are located above the ovary and the leaf veins are parallel.

Many hybrids and at least 190 cultivars have been developed, featuring many markings and colors, including white, yellow, orange, apricot, pink, red, purple, and lavender. The most popular and showy hybrids commonly grown today result from crosses between species from Chile (winter-growing) with species from Brazil (summer-growing). This strategy has overcome the florists’ problem of seasonal dormancy and resulted in plants that are evergreen, or nearly so, and flower for most of the year. This breeding work derives mainly from trials that began in the United States in the 1980s; the main breeding is done nowadays by companies in the Netherlands. The flower, which resembles a miniature lily, is very popular for bouquets and flower arrangements in the commercial cut flower trade. These delicate flowers survive up to 14 days in water without any signs of shriveling.

Most cultivars available for the home garden will bloom in the late spring and early summer. The roots are hardy to a temperature of 23 °F (−5 °C). The plant requires at least six hours of morning sunlight, regular water, and well-drained soil.

II. How to Grow and Care

Sunlight

For the best display of flowers, grow these plants in full sun. Many varieties can handle part sun, but they are much more likely to flop over and not be as floriferous.

Temperature and Humidity

Peruvian lilies like 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 essential to provide adequate spacing to help air circulation that will carry away spores of fungal diseases like botrytis.

Watering

Peruvian lilies need regular moisture, especially as summer temperatures heat up. Give them at least 1 inch of water weekly or when the soil surface feels dry.

Soil

Peruvian lilies like fertile, well-drained soil. You can accomplish both qualities by improving your soil with an organic amendment, like compost or leaf mold. These plants do well in most ordinary garden soil but prefer a slightly acidic pH (5.5-6.5). Peruvian lilies grow well in raised beds or using the lasagna gardening method.

Fertilizing

When first planting alstroemeria, add a high-nitrogen fertilizer, such as a 12-4-8, to the top few inches of soil, following the product label directions. Fertilize established plants with a high-nitrogen water-soluble fertilizer in early spring to support blooming, casting it on the ground while avoiding the foliage of the plants. Follow the product information for amounts.

Pruning

Cut Peruvian lilies back after blooming to prevent the plants from directing energy into seed production. Where plants have spread too much, pull up less productive stems to encourage younger plants from newly formed tubers to flourish.

Propagation

Peruvian lily can be propagated by dividing its roots or growing from seed. In their native habitat of Chile and Argentina, wild stands of Peruvian lilies grow and spread into large colonies. You can control their spread by cutting the flowers for display in a vase, also preventing reseeding.

The easiest and most reliable Peruvian lily propagation method is dividing the tuberous roots in the early spring before new growth begins. Here’s how:

  • Before you begin, you will need pruners, a shovel, and a new planting site.
  • Use pruners to cut off dead growth or remove green growth to a height of 6 inches.
  • Use a shovel to dig down several inches around the clump you want to divide. You may be unable to divide in large colonies without damaging neighboring plants.
  • Lift the entire clump from the ground and carefully brush off excess soil. Take care not to break the brittle roots.
  • Carefully cut apart clumps. Each clump should have at least three to five tubers.
  • Replant immediately in the garden. Dig a shallow hole, place the tubers over a small mound of dirt in the center of the hole, then cover it with about 2 inches of soil.

Growing from Seed

Growing these plants from seed is uncommon since germination rates are low and seeds require stratification. It can also take several years for seed-grown plants to flower. If attempting to sow seeds, plant many seeds since several will fail to germinate.

Here are the steps for seed propagation:

  • Collect the seed pods after the flowers fade.
  • Dry them until they are brittle and hard, and break apart the seed pods to harvest the seeds.
  • Soak seeds in room temperature water for 12 hours.
  • Sow seeds 1/4 inch deep in sterile potting mix.
  • Place the container in a cold location (about 40 degrees Fahrenheit) for one month. This cold stratification is necessary for the seeds to germinate and sprout.
  • After cold treatment, place the containers in a 70-degree location with bright indirect light until seedlings sprout. Germination rates are inconsistent, although it can occur from seven days to three weeks, if at all.
  • Once seedlings have developed their true leaves, move the container into a location with full sun to grow them into mature plants.
  • Take care when transplanting from pots, as these plants do not like to have their roots disturbed when they are young.
  • Plant seedlings in the garden 8 inches apart.

Pests and Diseases

Common Pests & Plant Diseases

Peruvian lilies are remarkably free of serious pests and diseases, though they can be affected by some of the usual garden pests, including slugs, mites, aphids, and whiteflies. Use insect soap or slug bait to prevent damage.

Some serious diseases that can affect Peruvian lilies include:

  • 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 its spread by spacing plants well apart to improve air circulation and watering at ground level rather than overhead spraying.
  • Various fungi can cause root rot, resulting in the leaves and stems wilting and collapsing even though the plants get enough water. Prevent root rot by amending soil so it drains well. Allow the soil to dry out to help this plant to recover. Severe rot will cause root blackening; discard or destroy plants with blackened, decayed roots.

Potting and Repotting

Your Peruvian lily plants can thrive in large containers; 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 vines, 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 a pot at least 8 inches wide and 24 inches deep. Any pot material will be fine, but make sure the container has ample holes for good drainage. Even larger pots are recommended in warmer climates where the Peruvian lilies remain outside year-round.

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. You can dig up, divide, and replant the tubers at the end of winter; use fresh potting soil when replanting. Keep the soil dry to avoid rot.

Common Problems 

Peruvian lilies are not temperamental plants and are generally easy to grow. However, some can experience a few common issues that are usually easy to rectify.

Plants Won’t Stay Upright

These plants have profuse flowers and rather spindly stems, so it’s common for them to flop over. This is a common problem for species grown as cut flowers, and it is easily handled by staking up the flower stems.

Well-watered Stems and Leaves Wither

This is a classic sign of root rot caused by various fungi.4 Most common in warm, wet weather, you can prevent root rot by ensuring 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. Usually, this happens as plants reach five or six years of age. It’s time to lift and divide the tuberous roots when this happens.

Overwintering

In warmer regions (zones 8 to 10), Peruvian lilies require no winter protection other than clipping back foliage as it dies back. Since zone 7 is a transitional zone, the plant roots should be covered with dry mulch for the winter.

Gardeners in colder zones than USDA zone 7 dig up and store the tubers for the winter. Here’s how:

  • Dig up the roots in the fall before the ground freezes.
  • Shake off the loose soil.
  • Place the tubers in a paper bag filled with peat moss. Hang them 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.
  • Spread the tubers over a mound of soil.
  • Cover with 2 inches of soil.
  • Keep moist as you wait for growth to emerge.

III. Uses and Benefits 

Alstroemeria are a low maintenance plant when established. Larger varieties can be used at the back of garden beds to bring bursts of colour where dwarf varieties can be used as perennial borders and in pots or containers. They make excellent cut flower particularly the taller varieties which is sort after by florists for their long stems. Alstroemeria cut flowers have a vase life of over 2 weeks. The Alstroemeria flowers are not fragrant which means they are a good addition for allergy sufferers who find scented gardens difficult to cope with.

Peruvian Lily (Alstroemeria) Details

Common name Lily-of-the-Incas, Parrot Lily, Peruvian Lily, Princess Lily
Botanical name Alstroemeria
Plant type Bulb
Hardiness zone 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b
Growth rate Medium
Height 1 ft. 0 in. - 4 ft. 0 in.
Width 1 ft. 0 in. - 4 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition High Organic Matter
Flower color Gold/Yellow
Leaf color Blue