Lupins: Cultivation of the protein bomb in your own garden

Lupins have a uniquely beautiful flower. Their seeds are also a protein-rich meat substitute alternative to soy, which can be grown in your own garden.

lupins (lupinus) are probably the most colorful representatives of the legumes (Fabaceae) and belong in every cottage garden. They impress with their large inflorescences, which are an ideal background planting in the perennial border. After flowering, the other benefits of the plants come to the fore. The seeds have a high protein content and offer a regional alternative soy. You can also improve every bed by planting lupins, because the plants loosen the soil and bind atmospheric nitrogen. In return, lupins only want a little sun, because otherwise they are extremely frugal in terms of location and care.

Lupins: properties and origin

The mostly herbaceous, perennial plants from 0.3 to 1.5 meters in size have their origin in North America. The plant, which is now growing wild here, came to Europe at the beginning of the 19th century. century. In Central Europe, the most common is the multi-leaved lupine (Lupinus polyphyllus) at. Other important crops are the yellow lupine (Lupinus luteus), the white lupine (Lupinus albus) and the narrow-leaved lupine (Lupinus angustifolius), which, like the multi-leaved lupine, has blue flowers and, as a cultivated form, also red flowers. Lupins are one of the richest sources of vegetable protein. Hildegard von Bingen already used them in preparations to cure all kinds of diseases. Lupine is said to have anti-cancer, antioxidant and antimicrobial effects. It is also suitable for diets related to protein deficiency diseases, diabetes, rheumatism, skin and stomach diseases.

Lupins: Distinguish poisonous from non-poisonous lupins

The seeds of garden and wild lupins in particular contain a poisonous bitter substance. The lupinine and sparteine ​​it contains can lead to respiratory paralysis and even death if consumed. However, since the 1930s, there have been certain cultivated forms that do not contain the bitter substance or only contain very small amounts and are therefore non-toxic. Due to the absence of bitter substances, they were given the name sweet lupins. Lupins can only become a problem for allergy sufferers who are hypersensitive to legumes. The keyword here is: peanut allergy. More to Toxicity of lupins Is there... here.

Lupins as a valuable food

Before we can add the lupine seeds to our diet, they have to be processed. Previous varieties had to be soaked in salt water for 14 days, the sweet lupine seeds are only soaked for 1 to 2 days. This removes the last bitter substances. Such pickled seeds are a popular beer snack in restaurants in the Mediterranean region. But the seeds can also be processed in many different ways. This gives you interesting alternatives for lactose-intolerant people, vegans and low-carb fans.

• lupine flour
  Lupins are mostly processed into protein-rich flour. The protein content can be up to 40%. That's about four times more than whole wheat flour. The high water retention makes the flour particularly interesting for vegans, since no eggs have to be used in baking. On top of that, the high content of antioxidants makes the baked goods last even longer. However, the flour still has a very strong flavor of its own, which is why it is recommended to keep the content at around 15-25% when baking. Otherwise you get a yellowish color and a nutty taste.
• lupine coffee
  This is all about a substitute for the wonderful taste of coffee, because lupine coffee does not contain caffeine. Thus, the stimulating effect remains. The taste scores with a slight hint of autumn leaves and almonds. For the production, the seeds are dried and then roasted. The lupine seeds refined in this way have a very strong, harmonious aroma, as they are roasted at low temperatures and therefore contain hardly any bitter substances. The beans are ground and prepared like regular coffee beans.
• lupine yogurt
  Lupine yoghurt offers a creamy alternative for vegans. This is obtained from lupine milk and is now available in different flavors from natural to raspberry to stracciatella. The consistency is slightly thicker than normal yoghurt.

A wide range of others lupine products and simple instructions for a delicious spread can be found here.

Lupins as green manure in the vegetable garden

A planting with lupins is great for preparing harvested or newly planted vegetable beds. Because lupins are very hardy and can be sown even after the vegetables have been harvested. They are also a very good nitrogen fertilizer. They enrich the soil with up to 100 kg of nitrogen per hectare. These huge amounts of nitrogen are fixed by a symbiosis between the lupine roots and nodule bacteria (rhizobia). In addition, the roots also penetrate compacted soil. This is loosened up and made more permeable for subsequent crops. Particularly deep-rooted varieties such as the yellow lupine (L luteus), the narrow-leaved lupine (Lupinus angustifolius) or the white lupine (L albus) are well suited for this. After the winter, the annual plants are mown and the cuttings are left as a layer of mulch. Once the layer has dried, it is worked into the ground. This is how the nitrogen gets into the soil and nutrient-rich humus is formed. The first new plants can be planted after four weeks.

Lupins in the garden

Lupins are not only suitable as vegetables, fodder and wild plants. With their up to 50 cm high inflorescences in white, yellow, blue-violet, pink, orange or multicolored, they have also found their way into our gardens as ornamental plants. Variants of the multi-leaved lupine (Lupinus polyphyllus) - also called perennial lupine - are offered.

Notice: Westcountry lupins convince with particularly intense flower colors.

Plant lupins: suitable location

Especially when it comes to the soil, there is not much to consider when choosing a location. The roots of the lupine are strong and due to their good nitrogen fixation, lupines also grow well on very sandy and poor soils. The following applies to the protein-rich plants:

• Location: Open, sunny and sheltered from the wind
• Soil: Moderately nutritious, permeable and poor in lime

Lupins also accept shadier spots. However, the flowering and the stability of the plants suffer as a result. If the soil is too calcareous (alkaline soil pH), the leaves will turn yellow. Waterlogging is also not tolerated.

Planting lupins: the right way to go about planting

Lupins are best planted in small groups in the bed. Here they form a brightly colored background for smaller perennials. When planting, proceed as follows:

• Planting time: early autumn or spring
• Planting distance: Approx. 50 cm
• Planting hole: Min. as deep as the root
• Place the plant carefully in the planting hole
• Fill with soil and press down
• Water well
• Water well for the next few days, but avoid waterlogging

If lupins are planted too densely, there is an increased risk of mildew. In addition, because of their deep roots, lupins are only suitable for pot culture to a very limited extent. If you still want to grow lupins in pots, stick to small-growing varieties, use a very high pot and have to overwinter the plants in a sheltered place in winter.

Propagate lupins yourself

Lupins are very easy to propagate by dividing, seeding or cuttings.

Sowing lupine seeds

In places that have already been planted, lupins will sow themselves. The seeds fly up to six meters away. The strong self-sowing means that lupins can quickly displace native wild plants in places they have once inhabited. Therefore, the multi-leaved lupine (Lupinus polyphyllus) with us as an invasive species. If you don't have lupins in your garden yet, sow them yourself. It is sown directly into the bed:

• Sowing time: March - May
• Slightly roughen the seeds with sandpaper and let them soak in water for 24 hours
• Sowing depth: 2 – 3 centimeters

The seeds can also be grown indoors in pots from January. From June, the small lupins then move outdoors. If necessary, perennial lupine species can also be sown up to the end of August. Regardless of whether it is grown directly in the bed or in a pot, the first flowering only begins in the following year.

more on the subject lupine seeds you'll find here.

Propagating lupins by cuttings

Propagation via cuttings also works without problems. The 5 to 10 centimeter long cuttings are cut in the spring. Then proceed as follows:

• Remove all but the top one or two leaves
• Fill the growing pots with a loose substrate such as expanded clay
• Insert the cuttings halfway into the substrate
• Location: Warm and not in full sun
• Keep substrate evenly moist
• After rooting (after four to six weeks), plant individually in pots with soil
• Plant out in the bed after a further six weeks

Caring for lupins in the garden

Lupins do not need much attention because they can take care of themselves quite well. However, they should be rejuvenated about every three years. For this, the rootstock is dug up in the spring and the new shoots are planted again.

Water and fertilize lupins properly

As such, once established, lupins don't need to be watered because of their very deep roots. If watering occurs after a long dry period or it has rained heavily, it is worth loosening the soil around the colorful protein bombs. This promotes long flowering. In addition, this prevents compaction of the soil, which is very beneficial for plants that are sensitive to waterlogging.

When it comes to fertilization, the motto is: less is more. Plants can be over-fertilized very quickly, increasing the risk of root rot and other diseases and pests. Due to the symbiosis with bacteria, lupins can provide themselves with nitrogen in particular. The additional mixing of rock flour or algae lime into the soil further promotes this symbiosis. If you want to strengthen the stems of the plants, some of which grow three meters high, fertilize with a primarily organic organic fertilizer like ours Plantura organic flower fertilizer with long-term effect.

Cut lupins properly

Lupins do not need to be cut into shape. But if the perennials have grown too big, the flower stalks can simply be cut back to the desired height. Pruning after flowering is more important. If the flowers are cut back immediately after flowering, this will encourage reblooming in the summer. In addition, faded flowers should be removed so that the lupins do not spread uncontrollably in the garden. You should remove diseased leaves all year round and immediately so that diseases such as powdery mildew cannot spread. It is not necessary to cut back above the ground in autumn. On the contrary: the upper part of the plant serves as winter protection for the roots and as green manure for the following year.

Caring for lupins in the garden: summary

• Rejuvenate every three years
• Watering: no longer necessary after growth; Avoid waterlogging
• Fertilizer: Sensitive to over-fertilization; Stone flour or algae lime promote the symbiosis with nodule bacteria; Bone meal strengthens the stems
• Sheaths: Remove inflorescences after flowering; remove diseased leaves

How do you harvest lupine seeds?

The pea-like inflorescences appear from late May to early August. They form pods that contain several of the coveted seeds. Harvest seeds for consumption only if you are sure about the bitter substance content. Especially with crosses that have been created in your own garden, it is possible that the bitter substances of the sweet lupine varieties that have been bred away will come through again in the following generation. There is a high risk of poisoning here. If you use the seeds for propagation, you don't need to worry.

When can you harvest lupine seeds?

Harvest in late summer when the seeds are fully mature. Ripe fruits can be recognized by the fact that the pods are dried and dark.

How to harvest lupine seeds ?

The seeds can be easily squeezed out of the ripe pods. Ripe seeds have a nice dark color. The seeds are cleaned with water and then dried so that they can be stored. Seeds are viable for two to three years in a screw-top jar in a cool, dark place.

The harvested lupine seeds can be processed in many ways. Check out our special article to learn more about how to Harvesting and using lupine seeds can.