How to grow and pick alstroemerias for endless flowers
Alstroemerias are very easy to grow. They flower from May to November in a UK garden and even longer in some other countries.
‘They’ll flower all year round if you keep them in pots in a greenhouse,’ says Ben Cross of Crosslands Flower Nursery, alstroemeria growers in Sussex. Also known as ‘Peruvian lilies’, they grow brilliantly in pots, too.
However, they are no relation to lilies. The flowers look like lilies, but there is no botanical link. This means alstroemerias aren’t toxic to dogs and cats, whereas true lilies can be a problem.
Peruvian lilies are also an exceptionally long-lasting flower in a vase.
I asked Ben for his advice on growing and picking them. Although they’re an easy and undemanding plant, you can’t cut them with secateurs and you don’t ‘prune’ them in the normal way.
Where to buy garden alstroemerias in the UK
Ben recommends growing ‘Indian Summer’ and ‘Rock and roll’ in the garden. ‘You can find alstroemeria growers at garden shows and online.’
Crosslands Flower Nursery only sell the cut flowers to florists and to individuals or companies for events, such as weddings. They don’t sell the plants to gardeners. But I’ve found good selections of garden alstroemerias available mail order from Alstroemeria Select, Thompson & Morgan and Burncoose Nurseries.
‘Because of the way the DNA works, the red/orange alstroemerias are the taller ones for the middle or back of a border,’ says Ben. ‘If you want the prettier, lighter colours, they’ll be shorter so you’ll need to have them at the front of a border.’
How to plant alstroemerias
Ben plants alstroemerias from 9cm pots. ‘First slip the plant out of the pot and check that there’s a good circle of white root around the bottom of the pot before planting it,’ he advises. If it doesn’t have much root, grow it on in the pot for a few weeks until more roots appear.
Then Ben just literally digs a hole in the ground and pops the plant in, making sure its roots touch the bottom of the hole. ‘Plant it about wrist deep,’ he says. Firm it up with soil and give it a light watering.
As a commercial grower, he keeps his soil in good condition, so doesn’t add extra compost when planting. If you don’t regularly mulch your soil with a layer of compost or garden manure, then you might want to add some at planting.
Where to plant alstroemerias
Peruvian lilies are easy to grow but they do better in some situations than in others. ‘If you’ve got a very open or windy garden, give them a sheltered spot,’ advises Ben.
And although they like sunlight, they don’t want to be baked. If they’re in full sun in the height of summer, their roots get too hot and they flower less, Ben explains. So they’ll be happy in light shade or areas which have some sun and some shade.
The taller alstroemerias will need staking.
How to prune alstroemerias
You should NEVER prune the Peruvian lily with secateurs. ‘We don’t do pruning, we do thinning,’ says Ben. ‘Look for stems that don’t have flower buds on them and tug them out.’ They come out complete with their single length of root.
‘If you cut – rather than pick – the stems off, then the root of that stem will stay in the ground and rot, possibly introducing rot or fungus to the rest of the roots,’ he says.
Pulling the non-flowering stems out will mean the plant can concentrate its energies on growing flowers. You’re allowing the remaining plant to enjoy more light and nutrients, so it will flower more.
How to pick alstroemerias
‘Never call an alstroemeria a ‘cut flower’ again,’ says Ben. You should always ‘pick it’, never cut it.
‘Picking’ is exactly the same technique as you use for thinning.
Firstly, choose a flower where the buds are almost out. They’ll be quite swollen, with obvious colour, but not yet open. ‘Flowers last longer if you pick them at the right stage,’ explains Ben.
Grasp the stem you’ve chosen around halfway down and tug gently, pulling out the entire length of root for that flower.
It’s more like harvesting rhubarb than cutting flowers.
Ben’s tips for long lasting Peruvian lilies in flower arrangements
You’ll be pulling out the full length of root, so cut that off and strip off the leaves. This means that the plant’s energy can be concentrated on the flower.
‘Change the water in the vase every two or three days. When you do that, re-cut the ends of the flowers. Bacteria will have grown around the ends of the stems, which prevents the uptake of water. Re-cutting the stems helps them take up water.’
Do alstroemerias grow in pots?
Ben strongly recommends growing them in pots. In the border, they can spread too much, but in pots, they can be contained.
You can also keep them flowering for longer if you move the pots from the garden to a greenhouse or conservatory in the winter.
‘But choose the shorter varieties,’ advises Ben. ‘Taller alstroemerias are more likely to get blown over.’
Use a standard potting compost – they don’t require anything special. But Ben says that alstroemerias are a ‘dry crop.’ Don’t over-water or allow the pot to sit in water.
Can you grow alstroemerias from seeds or cuttings?
You can grow alstroemerias from seeds, but Ben doesn’t recommend it. You shouldn’t try to propagate it from cuttings either.
But the roots do multiply easily in soil. Whether you grow it in a pot or in a border, Ben suggests that you re-pot or dig it out every few years. ‘The roots will have multiplied and you can pull them apart easily. I have tried harvesting the seed and replanting it but it hasn’t been particularly successful for me.’
Can you have too much of a good thing?
The fact that alstroemerias spread so easily is loved by some people, but not by others.
In some places, such as parts of Australia, alstroemerias are considered invasive non-natives. They can escape from gardens into the wild and out-compete native wildflowers.
It’s always worth checking what is considered invasive in your area. Sometimes planting it is forbidden. Or you may be allowed to grow it in your garden, provided that you take steps to make sure it doesn’t escape into the wild. In the UK, alstroemerias are not considered invasive.
I featured Frances Moskovits’ amazing herbaceous border here, so I asked her what she thought of alstroemerias. ‘We had some in the garden when we arrived, and I wouldn’t be without them now,’ she says. ‘Every spring I pull ten or so out, as I know there will be more following on. Then they come up through other plants nicely. I’d highly recommend them, especially the taller varieties. Plant them in clumps or dotted between other plants. Or both.’
However, my sister in law in Melbourne finds them just a bit too easy to grow. ‘Alstroemerias?’ she said when I asked her about them. ‘I find glyphosate does the job…’
More about Crosslands Flower Nursery and British Flowers Rock
As Crosslands Flower Nursery sell flowers to florists and individual clients in the UK, they’re able to pick them at the right time, package them up and send them on. They arrive with the client just a few days after picking.
Flowers flown in from abroad have to be picked earlier and are then chilled or frozen down to 0.5C while they’re transported to supermarkets and florists by air and land. They often arrive in your home several weeks after they’ve been picked. ‘So they don’t last as long,’ Ben says.
See more alstroemerias and Ben’s advice in video
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