how to plant, grow & care for alstroemerias
complete growing guide
Alstroemerias are one of the longest and hardest performing plants you can grow, so it’s always baffled me that they are sometimes looked down upon in gardening circles – perhaps it’s their reputation as supermarket cut flowers (they are very long-lasting in a vase).
I think avoiding that commercial feel is about picking the right varieties. The showy, lily-like flower heads in true, clear colours are best, from sumptuous, dusky crimson to fiery orange-red, all with fabulous blotches, dots and streaks. There are some seriously glam alstroemerias that not only look superb, but are good value and keep going long after more conventional flowers have run out of steam.
There are dwarf varieties that don’t get beyond 30cm (1ft) tall and work well in pots, but we mostly grow the border varieties that can shoot up to over 60cm (2ft) and are excellent for cutting. Each individual flower stem is long, branching at the top to make them rangy and elegant.
Like dahlias, alstroemerias are tender tubers, but they become hardy easily once established – with our increasingly mild autumns and winters, all it takes is a good mulch over the colder months and they will emerge the following season.
The remarkable thing about many of the modern varieties is that they flower for months at a stretch, pumping out three or four separate flushes of flowers. They don't seed everywhere and become invasive. After settling in for a couple of years, the new varieties spread slowly below ground, little by little, but not enough to become a pain – perfectly behaved, in fact.
We stock these new varieties of alstroemerias, sent out ready for planting from April through to early summer. Take a look at our full range of alstroemeria plants.
details
- Common name: Peruvian Lily
- Latin name: Alstroemeria
- Type: Tender Perennial, hardy once established
- Height: 30cm (1ft) to 60cm (2ft)
- TLC rating: Easy
- Aspect: Full Sun or Part Shade, Sheltered
- Planting position: Back, middle and front of border
- Suitable for pots: Yes
- Good for pollinators: Yes
- Good for cut flowers: Yes
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how to grow alstroemerias
where to grow alstroemerias
Soil type: Alstroemerias like fertile soil, so improve planting holes with organic matter such as compost. They also appreciate good drainage, so add plenty of grit to the planting hole, particularly if planting on heavy, clay soil.
Aspect & position: Alstroemerias need a sheltered site in full sun or part shade.
when to plant alstroemerias
Most alstroemerias should be planted anytime from April, but it’s best to wait for the risk of frost to pass.
how to plant alstroemerias
planting alstroemerias
Firstly, handle the tubers and plants with gloves, as the sap can cause irritation.
Alstroemerias are usually bought as small- and medium-sized plants to plant out in spring and summer. Find a sheltered, sunny spot for the plants.
Space them about 45cm-60cm (1½-2ft) apart and plant them deeply. The planting hole can be about 20cm (7in) deep. Add a handful of grit to improve drainage, some organic matter to improve the richness, and a sprinkle of mycorrhizal fungi.
If you plant them deeply, the tubers will sit below the normal soil frost level, protecting them and helping them become established and hardy. Mulch the clumps in autumn and winter to protect them further, and they will reliably overwinter outside.
If you have a greenhouse it is well worth growing alstroemerias inside too. Pot them up into 5 litre pots in free-draining, gritty compost. Keep them frost free. Feed and water well once they start to shoot in spring and they should give you an almost continual flower harvest. Pull from the root and they will continue to flower for months.
how to care for alstroemerias
watering
Water alstroemerias regularly during a prolonged dry spell, but they are relatively drought-tolerant. Water alstroemerias in pots and any in a greenhouse.
fertilising
Add a slow-release fertiliser in the spring to encourage flowering. Use a high-potash fertiliser for any container-grown alstroemerias such as comfrey or tomato feed.
staking
Alstroemerias can reach over 60cm (2ft) and their big lily-like flowers can make them top heavy, so unless they are in a very sheltered spot, the taller varieties will need staking so they don’t collapse in the wind or rain. Tap in a cane and tie in the stems, or if you have a big patch of alstroemerias, stretch jute netting over them.
deadheading & harvesting
Keep harvesting the flowers or deadheading any faded flowers. The best way to pick or deadhead alstroemerias is to pull them like rhubarb, rather than cut the stems. Hold the lower part of the stem and give it a quick, stout yank – you’ll have a very long, sometimes twisty stem, but they can be trimmed easily if you want them for a vase.
Doing it this rough way (rather than cutting) provokes more flowering stems to form and gives you a more productive plant.
For more on the technique, watch my video on harvesting alstroemerias below.
dividing
After settling in for a couple of years, alstroemerias spread below ground, little by little. Propagate alstroemerias by division every couple of years to avoid congestion. The roots are fragile and need to be lifted and divided with care and replanted immediately. Do this during their dormant period in early autumn or alternatively in April.
Divide the clump and replant elsewhere in the garden in a planting hole that’s about 20cm (8in) deep – add a handful of grit to the planting hole to improve drainage.
overwintering
Like dahlias, alstroemerias are tender tubers. They become hardy easily once established, and with our increasingly mild autumns and winters, all it takes is a good mulch over the colder months and they will emerge again the following season.
Mulch deeply for the first couple of winters to give them the best chance, and particularly if you live in a cooler part of the country.
It’s worth noting that hardiness used to be a problem with some species and earlier-bred hybrids; they would start to shoot in April and would then be cut down by frost, which would knock them right back. But modern, early-flowering varieties are made of sterner stuff. Some can be cut down by frost and just come straight up again.
seasonal checklist
spring
- Plant young alstroemeria plants in a sunny, sheltered position.
- Use a slow-release fertiliser to encourage flowering.
summer
- Pick flowers and deadhead any fading flowers.
autumn
- Enjoy the last alstroemeria flowers, which will go on until the first frosts.
winter
- Mulch deeply, particularly over newly planted alstroemerias, to help them establish.
pests, diseases & common issues
why is my alstroemeria not flowering?
Improper harvesting can impact flowering – pull the stems with a yank to harvest, rather than cutting. See my video above for a full demo. Another issue may be that the tubers have been sitting in waterlogged soil, which can lead to rot. Make sure the soil is free-draining and you don’t overwater the plants.
why is my alstroemeria dying?
It could be that the tubers weren’t planted deeply enough and the winter frosts have got to them. Plant alstroemerias relatively deeply and mulch over winter. Again, it could be tuber rot due to waterlogged soil. Or perhaps the plants aren’t getting enough sun to thrive.
why are my alstroemeria leaves turning yellow?
Cold temperatures and waterlogged soil could be two causes – mulch alstroemerias over winter and improve drainage.
what is eating my alstroemerias?
Slugs and snails love young alstroemerias, so ensure you employ plenty of protection as soon as you plant them.
how do I keep alstroemerias from falling over?
Taller varieties of alstroemerias will need staking, particularly if they are in an exposed site and caught in strong winds. Tap a cane into the ground and tie in the stems.
frequently asked questions
are alstroemerias poisonous to cats, dogs or other pets?
Yes, alstroemerias are toxic to cats, dogs, horses and other pets. Humans should also handle with care: always wear gloves when deadheading and planting as the sap can cause skin irritation.
do alstroemerias spread?
Alstroemerias are clump forming and the tubers will multiply and spread over time. You can lift and divide the plant every couple of years to reduce congestion – and give yourself more plants for the garden.
can alstroemerias grow in shade?
Partial shade is fine for alstroemerias (though do check the variety you are growing), but full shade will impact flowering.
can you grow alstroemeria in pots?
Yes, alstroemerias are suitable for containers, particularly the dwarf varieties. They are also excellent as greenhouse plants.
are alstroemerias lilies?
No, they are not lilies. They are native to South America, which explains the sometimes confusing common name Peruvian lily or lily of the Incas.
can you split alstroemerias?
Yes, after a few years of bulking up, alstroemerias can be lifted and divided.
what does alstroemeria mean?
Alstroemeria is named after Clas Alstromer, who was an 18th century Swedish nobleman.
do deer eat alstroemerias?
Luckily, alstroemerias are not a deer’s first choice of meal.
how to cut & arrange alstroemerias
To harvest alstroemerias, you need to pull the stems like rhubarb, rather than cut them. Watch my video about harvesting alstroemeria where I show you the technique.
Alstroemerias will last 2-3 weeks in a vase, which is exceptionally long for a cut flower. Arrange them with a drop of vinegar in their flower water to extend their life. They go for so long that you need to tip out water and replace it with fresh every 4-5 days.
Get more inspiration for displaying your flowers with our flower arranging videos:
