Inca lily, alstroemeria: to plant, to grow, to maintain

Description and Botany

The Alstroemeria, commonly known as lily of the Incas or Peruvian lily, belongs to the family Alstroemeriaceae (formerly Liliaceae or Amaryllidaceae) and comprises around fifty species, all native to South America, primarily the Andes. All plants in this genus are perennials with tuberous and rhizomatous roots. The hardiest species are native to the Chilean Andes and Patagonia, such as Alstroemeria aurea (syn. aurantiaca), which can tolerate temperatures as low as -16°C and is found in humid wooded areas at altitude. It prefers cool but not waterlogged soils in our colder climates. The species A. ligtu, with pink flowers and resistant to -15°C, grows in dry thickets on sandy or rocky soils in Chile, as does A. haemantha, found in the Valparaiso region, which can withstand frosts down to -10°C.

These last two species have been the subject of hybridization following the visit to Chile by British horticulturist Clarence Elliott (1881-1969) in 1927. The Dutch company Van Straaveren B. V. from Aalsmeer became interested in producing cultivars for cut flowers, which also make excellent garden plants with a hardiness of -10°C. Recent cultivars are often more compact, measuring 50 to 80 cm in all directions, resulting from cross-breeding with A. aurea and are triploid. They are sterile and therefore do not produce fruit, which facilitates the continuation of flowering. These cultivars are more reliable and more resistant to our wet and cold winters.

Alstroemeria – botanical illustration

The clump of alstroemeria produces upright stems reaching heights of 30 cm to 1 m, adorned with alternate, ribbon-like or lanceolate leaves measuring 10 to 12 cm long, ranging from glossy green to grey-green, and sometimes even bronze with purple highlights. It spreads quite rapidly due to its fine, brittle tuberous roots, sometimes becoming invasive. The petioles connecting the lamina to the stem are uniquely curled, giving the foliage a frizzy appearance. From June onwards, and often until the frosts for hybrids, generous umbels of striped and spotted flowers crown the sturdy stems. The clump completely disappears at the first frost, making it difficult to spot before it emerges in spring.

The flowers, measuring 4 to 10 cm long, can be tubular as seen in the botanical species A. psittacea or have an open trumpet-shaped corolla. The bilaterally symmetrical flowers feature 6 tepals (3 petals and 3 similar sepals) with variations in colour. The petals, which are slightly narrower than the sepals, often display large bright yellow areas striped with brown, designed to attract pollinating insects. The flower has 6 curved stamens and 1 pistil. Some are even fragrant, such as the Brazilian species Alstroemeria caryophyllacea, which emits a surprising clove-like scent passed on to its hybrids like ‘Sweet Laura’.

Inflorescences in various colours: Alstroemeria ‘Mars’, Alstroemeria ‘Sweet Laura’, Alstroemeria inticancha ‘Indian Summer’, Alstroemeria inticancha ‘Sunday’, Alstroemeria ‘Majesty’.

The main varieties

Most Popular

Our Favourite Varieties

Alstroemeria aurantiaca

Perennials for fresh, well-drained soil in light, cool woodland areas. Slow to establish, they may disappear or... become invasive! Erect stems with lanceolate leaves. Numerous orange flowers, 3-4 cm wide, resembling small lilies.

• Flowering time August to October
• Height at maturity 80 cm

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Alstroemeria Inca Pulse - Peruvian Lily

Pretty red and yellow flowers speckled with reddish-brown. Superb in bouquets and garden borders.

• Flowering time July to November
• Height at maturity 50 cm

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Alstroemeria Mars

A variety from the 'Planet' series, brightly coloured, hardy, floriferous, and reliable. Its beautiful flowers of intense red speckled with yellow and striated with brown enliven the garden or terrace throughout summer and allow for the creation of sumptuous bouquets. They bloom on a vigorous, upright, and bushy plant, easy to grow in light, fertile, well-drained soil that is not too dry in summer. This Inca lily withstands frosts down to -15°C, protected by mulch.

• Flowering time July to October
• Height at maturity 80 cm

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Alstroemeria Indian Summer

A recent variety that combines qualities: its flowers in flamboyant shades of yellow, orange, and red are borne on tall, very sturdy stems, adorned with unique foliage, green-bronze with purple highlights. This variety is quite hardy (-10°C) and very resistant to diseases.

• Flowering time July to November
• Height at maturity 70 cm

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Alstroemeria aurantiaca Orange King

An old variety still highly appreciated for bouquet making. This Inca lily bears in summer, on floral stems of 80 cm, flamboyant flowers of bright light orange touched with yellow and delicately striated with brown. It is also very beautiful in the garden and in window boxes.

• Flowering time August, September
• Height at maturity 80 cm

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Alstroemeria Sweet Laura

This surprising variety produces strong clumps, throughout summer, small golden-yellow flowers speckled with burnt orange and striped with mahogany brown, pleasantly fragrant. While its flowers are wonderful in a vase, it is also a superb border plant that is easy to grow in most of our climates.

• Flowering time July to October
• Height at maturity 70 cm

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Alstroemeria Inticancha Cabana - Peruvian Lily

This Inca lily from the Inticancha® series will not disappoint. Particularly robust, floriferous, and compact, it produces continuously bicoloured flowers that are almost white with a yellow throat beautifully striated with purple, borne on very sturdy low stems that are weather-resistant. Ideal for flowering pots.

• Flowering time July to November
• Height at maturity 35 cm

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Alstroemeria Inticancha Sunday

This Inca lily from the Inticancha® series is a very recent variety, offering a bunch of lilac-pink flowers with a yellow centre striped with brown, full of freshness. They appear from spring to autumn, covering particularly robust and floriferous plants, ideal for borders or in flowering pots. Their sturdy stems withstand the weather well. This not very hardy perennial is, however, easy to grow as an annual and requires very little maintenance.

• Flowering time July to November
• Height at maturity 60 cm

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Alstroemeria Mauve Majesty

Undoubtedly the first truly hardy Inca lily in this range of colours. This excellent variety is distinguished by its charming cream-speckled mauve-pink flowers striped with purple at the throat, its sturdy floral stems of 65 cm, and its exceptional cold resistance. Imperial in sunny borders and beds, it blooms throughout summer and its flowers last 15 days in a vase!

• Flowering time July to October
• Height at maturity 65 cm

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Planting Inca lilies

Where to plant?

Inca lilies appreciate a location benefiting from morning sun, or partial shade under the light foliage of a tree with light leaves like that of the Albizia.

They require light, well-drained, well-worked soil, sandy or loamy with low lime content, neutral to slightly acidic. The coolness of the soil helps support flowering, but they adapt quite well to drier soils in summer. They can easily colonise a clear understorey or a bank.

These plants are quite hardy as long as the soil does not remain waterlogged in winter. In cold regions, the stump can be protected with a thick mulch of leaves, dry turf, or fern fronds, applied in autumn. Slugs and snails love the young shoots, which need protection if you want to keep the plant.

As the plant completely disappears in autumn, it is advisable to mark its location. Do not disturb the clump with a hoe: the tuberised roots are often wandering and fragile. Weeding should be done by hand with care.

Choose the location carefully, as once established, alstroemerias do not like to be moved!

When to plant?

Plant alstroemerias in spring, between March and May, or even early summer if you buy a potted plant. Avoid disturbing the roots during flowering. Note that young plants sold in buckets take 2 to 3 years to form a lush clump, except for the new hybrids.

How to plant?

To plant your alstroemerias:

1. Space the plants 40 to 50 cm apart.
2. Moisten the root ball to facilitate recovery.
3. Dig a planting hole, two to three times the size of the root ball. Add a bit of decomposed compost or organic fertiliser.
4. Place the plant in the hole slightly below soil level to provide more coolness to the roots.
5. Ensure the roots from the rootstock are placed vertically. Trim them if necessary.
6. Replace the soil and lightly firm it down.
7. Water.
8. Spread a layer of mulch to maintain good coolness around the roots. This will also limit the growth of weeds. 

For a pot culture, place a draining layer of 3-4 cm at the bottom of the pot (gravel, broken pottery, etc.). Add a mixture of potting soil and non-lime garden soil. Also, read our dedicated advice sheet: Succeeding with Alstroemeria in pots,

Close-up of an Inca lily flower.

Maintenance and watering

Alstroemerias require regular watering to maintain flowering. Water at least once a week during the warm season to ensure impeccable and abundant flowering.

• Cut faded flowers to encourage regrowth even though most hybrids do not produce fruit.
• Add flowering plant fertiliser, especially to potted plants, to stimulate flowering.

The plant is very resistant to pests and diseases. However, it is regularly attacked by slugs and snails in spring. A layer of fern mulch has a repellent effect on these pests.

Multiplication: division and sowing

You can multiply the alstroemeria by clump division every 5-6 years; this is the simplest method to implement. Sowing is possible when it comes to botanical species; however, this technique does not allow for a high success rate.

Clump Division

Operate in spring during March-April or just after flowering at the end of summer on a subject at least 3 years old.

• Dig up the clump by giving 4 spade strikes of at least 20 cm deep, then gently lift it.
• If necessary, cut the clump with a knife to separate blocks of roots and stems.
• Replant immediately in a hole 20 cm deep, enriched with decomposed manure or organic fertiliser.
• Place the roots coming from the rootstock vertically. Do not hesitate to trim them cleanly if necessary.
• Close the hole and water generously but without excess.
• Mulch with ferns to maintain moisture and deter slugs.

Sowing

Only botanical species such as Alstroemeria aurea or psittacea will give you flowers identical to the mother plant. This operation remains quite delicate for the amateur gardener.

1. You can soak the seeds for a few hours in water before sowing them.
2. Sow the seeds in spring (around March-April) in a sandy substrate that you place in a well-lit heated greenhouse.
3. As soon as the leaves appear, transplant the seedlings into 9 cm buckets filled with turf.
4. Wait until the following spring to plant the young plants in the ground or in pots.

Using and Combining Alstroemeria in the Garden

With its orchid-like appearance, the Inca lily makes a statement regardless of its use.

The compact forms lavishly highlight the borders of a bed, a path or illuminate a partially shaded bank covered with Epimedium or Pachysandra. They can be grown as annuals given the exceptional duration of their flowering.

An example of a warm-toned combination: Alstroemeria ‘Inca Tropic’, Pennisetum orientale, Eremurus ‘Cleopatra’, Phlomis russeliana, Achillea millefolium ‘Paprika’.

The tall forms are perfect for filling large mixed-border beds. They pair splendidly with generous plants such as landscape roses, Agapanthus (Golden Drop, Silver Moon), Amaryllis, Crocosmias, Dahlias, Echinaceas, Foxgloves, or even Phlox. To lighten the scene, consider mixing them with the delicate flowers of Fuchsias magellanica, of Gaura, the graphic stems of Verbena bonariensis, or even with grasses (Stipa, Miscanthus dwarf, Muhlenbergia capillaris, etc.). Their sturdy, robust stems are weather-resistant and do not require staking. However, avoid planting them in full wind.

For more combinations, discover our 7 ideas for combining alstroemerias.

Did you know?

• The flower of the alstroemeria is the flower of happiness, symbolising the joy of being together, in friendship as well as in love. Giving a bouquet of Peruvian lilies allows you to convey your wishes for happiness and prosperity!
• The genus Alstroemeria honours the Swedish botanist and naturalist Clauss Alströmer, who sent seeds of A. psittacea to Linnaeus from Spain.