How to grow alstroemerias
A great addition to borders and containers, alstroemerias produce showy flowers in a wide choice of colours from early summer to the first frosts. Most are hardy and easy to grow, blooming generously for many years. They also make long-lasting cut flowers.
- Clusters of colourful lily-like flowers
- Bloom from early summer to late autumn
- Perennials, so will live for many years
- Most are hardy, but do give them a warm, sheltered spot
- Need sun or partial shade
- Grow in borders and containers
- Plant in spring or autumn
All you need to know
What are alstroemerias?
Alstroemerias are fleshy-rooted herbaceous perennials, which means they grow from bulb-like tubers, producing new leafy stems every spring, flowering in summer and autumn, then dying down over winter. They live for many years, and although they look very exotic they are generally hardy, so can be left in the ground over winter.They originate from South America, hence their common name of Peruvian lilies. They have been widely bred to produce a stunning range of flower colours, with petals often dotted, blotched or streaked with additional hues.
The lily-like flowers are held in clusters at the top of leafy stems, which are produced in succession from early summer to late autumn. These can range in height from just 15cm (6in) up to 1m (3 ¼ft) or more.
Choosing the right alstroemerias
As long as you can provide a warm, sheltered, sunny spot in free-draining soil, alstroemerias should be happy in your garden. The flowers attract bees and other pollinating insects, so alstroemerias are perfect for a wildlife-friendly garden.
There is a wide range of cultivars to choose from, with flower colours that will match or contrast with your existing plants. They grow to various heights to suit all positions in borders and even containers:
- Flowers – the vibrant lily-like blooms come in shades of purple, pink, red, orange, yellow or white, often blotched, speckled or striped with additional colours. This diversity means there are choices to fit most colour schemes and styles of garden, from bold exotic plantings to romantic cottage-style borders. They mingle well with other
and will extend your flowering displays well into autumn perennials
Perennials are any plant living for at least three years. The term is also commonly used for herbaceous perennials which grow for many years (To compare: annual = one year, biennial = two years).
- Foliage – the leaves come in various colours too, from bronze, grey-green to variegated cream and green
- Plant size – they generally grow to between 50cm (20in) and 1m (3¼ft) tall, but there are taller and shorter options too, to suit all positions in a border. The compact cultivars (from 15cm/6in tall) also work well in containers. Check plant labels for height and spread before buying
There are 15 alstroemerias with an RHS Award of Garden Merit, which shows they performed well in RHS trials, so are reliable choices.
To browse photos and descriptions of alstroemerias, go to RHS Find a Plant. You can search by flower colour, height, growing conditions, RHS Award of Garden Merit and more, to help narrow down your choices.
How and what to buy
They are mainly sold as small plants in spring or larger plants in flower in summer and autumn
It is best to buy container-grown plants rather than drytubers (similar to bulbs), as the latter often fail to grow
Tubers are swollen, usually underground, parts of a stem or root used to store food by the plant. They have buds that can produce new plants. Examples are tuberous begonia, cyclamen, dahlia and potato.
Online suppliers sometimes offerbare-root plants and plug plants, which need potting up and growing on, before they can be planted outside. See our guide to buying plants by mail order
These have been lifted from the ground while dormant, with little or no soil around their roots. Various plants may be available bare root, including fruit trees, hedging plants and some perennials. They are generally cheaper than plants in containers, but are only available in winter/early spring, while dormant
Use RHS Find a Plant to track down stockists of specific cultivars.
Where to plant
Alstroemerias like a warm, sunny, sheltered spot. They will tolerate light shade, but flower best in sun. Avoid planting in a particularly cold or exposed location. See our guide to assessing your garden conditions
Avoid planting taller types in a windy site, as the flower stems may get damaged
Fill a large container with John Innes No 2 compost, with added grit (20% by volume) to ensure good drainage
Move the container to a frost-free location over winter
When to plant
The best time to plant alstroemerias is in spring or autumn, when the soil is relatively warm and damp, so the roots establish quickly
If you buy alstroemerias in flower in summer, plant them straight away and take care to water them regularly for the rest of the summer, to help them settle in
How to plant
Alstroemerias are quick and easy to plant in borders and containers. Simply follow our guides below.
Alstroemerias are generally drought tolerant, but it is worth watering them in dry periods to encourage further flowering.
Plants in containers need regular watering throughout the growing season, as the compost will dry out quickly, especially in summer.
RHS video guide to watering efficiently
To encourage bountiful and continued flowering, feed weekly with high potash fertiliser, such as tomato feed, throughout the growing season.
It is particularly beneficial to feed plants in containers, as they have less access to nutrients than plants growing in border soil.
Supporting tall plants
It is best to support all but the compact alstroemerias, using either twiggy pea sticks or stakes. This will prevent the flower-laden stems breaking in windy weather or heavy rain.
Alstroemerias make particularly long-lived cut flowers, staying fresh for a couple of weeks in a vase:
To pick, grasp the stem gently, low down and pull upwards – a quick tug. This severs the stem below ground and stimulates another bud, so you get another flush of blooms. You can then trim your picked stem to the required length
However, in the first summer after planting, flower stalks are best cut rather than pulled, until the plant is firmly rooted in
Once all the flowers in a cluster have faded, remove the whole stem with a gentle tug, the same as picking. This encourages further flower stems to sprout, keeps the plant looking good, and prevents it wasting energy on producing seeds at the expense of more flowers.
Plants in borders
Most alstroemerias are hardy and should survive the winter outdoors once their roots are well established and have grown deep into the ground.
However, for the first couple of years after planting, apply a thick layer of mulch in autumn to the soil around the plant, to help insulate the roots. Composted bark is an ideal mulch, in a layer about 20cm (8in) deep.
Plants in containers
These should be moved to a frost-free location over winter, as the roots are more exposed to low temperatures than when growing in the ground
This will also help to stop the compost getting saturated with excess winter rainfall, which can cause the roots to rot
A sheltered porch or greenhouse would be ideal overwintering locations
Caring for older plants
Plants in containers should be re-potted every other year, into a container that is only slightly larger. See our guide to looking after plants in containers.
Established clumps in borders can be divided every few years to keep them vigorous and flowering strongly. See Propagating below.
Alstroemerias need little pruning. During the growing season just remove the spent flower stems right at the base to encourage more to grow, then remove any remaining old stems in early spring before the new shoots appear.
The quickest and easiest way to make new plants is by dividing mature clumps. The resulting plants will be exactly the same as the parent plant.
Alstroemerias can be tricky to grow from seed, and if using collected seeds the resulting plants may differ from the parents. Plants grown from seed will take several years to reach flowering size.
Established plants can be divided in April. However, the roots are fragile, so lift and divide plants with care, and replant the new divisions immediately. See our step-by-step guides below.
RHS video guide to dividing perennials
Alstroemerias can be tricky to grow from seed, and even with careful attention germination is not reliable.
However, it is easy to collect seeds from your own plants if you don’t deadhead them – just bear in mind that the resulting plants may differ from the parent. You can also buy packeted seeds, but the choice is limited.
Seeds are best sown in autumn
Pods can be collected from the plants as they turn brown and kept in a sealed paper bag until they explode. The seeds should then be sown immediately
Sow in peat-free seed compost in 8cm (3in) pots and cover the seeds with a thin layer of vermiculite. Cover the pots with cling film or a plastic bag to maintain humidity
Keep indoors at 20ºC (68ºF) for three weeks
Then place in a coldframe or cold greenhouse at 5ºC (40ºF) for three weeks
After this, bring back indoors at 20ºC (68ºF)
Germination can be erratic
The roots are fragile, so don’t separate the seedlings – keep in clumps when potting on and planting out
The resulting plants should flower in two or three years.
When grown in the right conditions, alstroemerias are generally trouble free. However, do look out for the following issues:
Winter cold – especially when newly planted, alstroemerias may suffer in freezing temperatures. Until they have put down deep roots, it is best to protect them with a thick layer of mulch over the root zone in autumn
Rotting – in damp conditions, the roots are prone to rotting, so grow in free-draining soil or compost. Bring container plants under cover over winter, so they don’t sit in cold, wet compost
Viruses – may occasionally be a problem
If you’re a member of the RHS, you can use our online Gardening Advice Service, via MyRHS, for any gardening queries.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.