Lupin seeds: protein-rich seeds from your own garden
Lupin seeds are rich in protein and thus can serve as a homegrown alternative to soy. Here you can learn everything important about lupin seeds.
Lupins (Lupinus) thrive beautifully at our latitudes. This means the protein-rich legume (Fabaceae) can also be grown in the home garden, where they delight with their colourful flowers while sprucing up the soil. If you pay attention to the right varieties when planting, nothing will stand in the way of your own harvest of the superfood.
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Lupins: characteristics, requirements and origin
The protein bombs originally come from North America. It was not until the 19th century that the lupin was brought to Europe. Due to their undemanding character with regard to the soil, their rapid growth and the high potential for self-seeding, the colourful plants belong to the invasive species that quickly displace native species and are now also considered native here. Lupins are an effective green manure, a domestic alternative to soy as a forage crop, and in the form of seeds can be processed into a variety of protein-rich and healthy foods. But it is not only the protein that makes the seeds interesting. The plant is also rich in antioxidants and has an antimicrobial effect.
Like peas, beans or peanuts, lupins belong to the legume family (Fabaceae also Leguminosae). All legumes, like lupins, have two characteristics that make them very interesting as a crop. On the one hand, the plants of this family are able to form symbioses between their roots and bacteria that optimise the supply of nutrients. On the other hand, the seeds have a high protein content. Unfortunately, many people are allergic to legumes. This means lupins are among the major allergens. Allergies are triggered by certain proteins that are mistakenly labelled as dangerous by the human immune system. As a result, immune reactions occur which, in the worst case, can cause anaphylactic shock and even death. How such food allergies develop has not yet been scientifically explained. What is certain, however, is that you must be careful when eating lupins for the first time if you have allergies to other legumes. This is because so-called cross-allergies often occur.
Lupins as green manure
Lupins are excellent as green manure in agriculture or in their own beds. During the growth phase, plants store vast amounts of nitrogen. For this purpose, the plants enter into symbioses with nodule bacteria (Rhizobia). The bacteria colonise the roots, fix atmospheric nitrogen and pass it on to the plant in a form that the greenery can utilise. If the lupins rot, these bound nutrients are released back into the soil and are available for the next plants to take root in place. Proceed as follows for green manuring:
- May: Sowing annual lupins in the place to be improved.
- After the winter: Mowing down the lupins
- Leave cut as mulch layer
- Allow layer to dry and then work into the soil
- After four weeks new plants can be sown/planted
But lupins do more than just pass on nutrients. Their strong roots reach very deep and loosen the soil.
Growing requirements in the garden
Lupins do not have many requirements in terms of the place where they grow. Only a little sun is needed so that the lupins bloom and dazzle for an extended period. The soil is loosened by their powerful roots but should not be too calcareous. Later care is also not a big problem, because the deep roots and symbiosis with nodule bacteria provide excellent self-sufficiency. For those who want more detailed information about cultivating lupins in your own garden, here is everything that might interest the inquisitive amateur gardener.
Lupin seeds: energy bomb from the garden
Lupin seeds have a protein content of up to 40% and are increasingly seen as the Nordic alternative to imported soy. However, lupin products are more expensive than the soy variants. The temptation is great to simply harvest the seeds yourself. But great care should be taken when consuming untested lupin seeds.
Caution: Only the seeds of the sweet lupin are edible
Originally, lupins have a very high content of bitter substances. These chemical compounds, in this case predominantly lupinine and spartein, are toxic to humans as well as most animals. Therefore, do not entertain the idea of simply harvesting lupins discovered in meadows and eating them without pre-treatment. The lupin seeds used for food belong to special cultivars, the sweet lupins. These contain no or virtually no bitter substances and can be processed without hesitation. For more on distinguishing lupin species, as well as possible signs of poisoning and what to do in an emergency, see our article “Are lupins poisonous?”.
Harvesting lupin seeds in the garden
Lupins form vast quantities of seeds with which they can spread in the garden – usually faster than one would like. If you do not want to harvest seeds and want to prevent their spread, simply cut off the faded flowerheads. However, if you wish to harvest the seeds for propagation or consumption, the flowerheads should be left on the stems. They later form the pod fruits, which contain the much sought-after seeds.
When are lupin seeds ripe?
The ripeness of the seeds is indicated by the appearance of the pods. The seeds are ripe when the pod is dried and dark. This is usually the case in late summer.
How to harvest lupin seeds
Once you have harvested ripe pods, the harvest is completed in no time. The seeds can then be easily pressed out of the pod. The dark seeds are then cleaned with water and dried.
Using lupin seeds
Lupin seeds can be used in many different ways. On the one hand, they serve to propagate the plants. On the other hand, the protein-rich seeds can be further processed into healthy foods that are free of animal ingredients.
Using lupin seeds for propagation
Dried seeds are still germinable after three years if they have been stored in an airtight and dark place. The seeds are sown directly into the bed but can also be grown indoors in a pot. Proceed as follows:
- Sowing time: March – May (in a container: January)
- Lightly roughen seeds with sandpaper
- Soak seeds in water for 24 hours
- Sowing depth: 2 to 3 centimetres
- Perfect for herbs as well as sowing, propagating & transplanting
- For aromatic herbs & healthy seedlings with strong roots
- Peat-free & organic soil: CO2-saving composition
Pre-grown lupins in pots are planted out in the bed from June. Perennial lupins can be sown in the bed even into August.
Processing lupin seeds
The product range for lupins is increasing rapidly, because more and more people are concerned about a conscious diet. The number of vegetarians and vegans is increasing every year and the market is naturally responding to the increasing sales opportunities. Unfortunately, soy does not thrive in our country and must be imported with resulting high emissions. Lupins, however, can be grown locally, making them suitable even for home growers. Those who harvest themselves or buy lupin seeds in stores have many options for further processing the seeds. However, lupins are already available for purchase in processed form. A selection of delicious foods made from lupin seeds – from ice cream to coffee.
