Lupin

Lupin is a flower that characterises early summer in Sweden. The large flowers catch the eye, spread a lovely scent and attract pollinators. They look good in the midsummer pole and as cut flowers. You can also grow lupins where not many other plants thrive. Lupin originally comes from North America. Today, lupins are grown as ornamental plants in many parts of Europe. Many people love lupins, but others see them as a weed. Here we will go through both the pros and cons of this interesting perennial.

Lupine flowers in many colours

A lupine is a plant that grows around 200 flowers that are clustered together at the top of the stalk. A lupine flower can have many different colours. Pink and blue are common, white and violet are also common. By growing rainbow lupins, you can get flowers of many different colours on the same plant.

Tips for those who want to grow lupins

Lupin thrives in almost all parts of the country and it is not difficult to grow lupin from seed. However, here are some tips that can help you get more out of growing lupins:

• Soak the lupin seeds for 24 hours before sowing to speed up germination.
• Cut off the inflorescence after flowering to avoid seed formation. This gives the lupin a chance to flower once more.
• You can grow lupins in pots, especially lower varieties.
• Take root cuttings if you want a lupine with the same colour as the mother plant. If you grow lupins from seed, you can’t control the colour.
• Lupins love the sun but can also thrive in a shady position.

Invasive lupin

Lupin has a reputation for being very invasive. This means that lupin seeds spread and the plant easily takes hold outside the area where you want it. Growing lupin in a confined bed can be difficult unless you are prepared to spend some time looking after the stock. The fact that it spreads also means that you can quickly transform an area in a rather drastic way. However, it’s important to grow lupins responsibly. If they spread beyond your property boundary, it is at the expense of other plants. Biodiversity is affected. If you have lupins that have set seed, you can soak them to rot before throwing them in the compost.

If you sow lupins from commercially available seeds, you will get flowers with different characteristics than invasive wild lupins. The problem of invasive lupins is then not as big.

Lupins can be used as green manure

Lupins have one sought-after property and that is that they loosen up the soil with their roots as these go very deep. In addition, the leaves fix nitrogen and act as green manure. Farmers can grow lupins as part of a crop rotation, as a soil amendment. Some varieties can also be used to feed pigs and cattle. However, according to the Swedish National Food Agency, lupins contain alkaloids that can be toxic to humans. In particular, the bitter lupin variety is considered toxic, while the sweet lupin variety is not as toxic.

Author: Johanna Damm

Fact-checked by Erik Hoekstra

Last updated 2023-12-11