The unusual flowers of the Lupine plant make them a special attraction in the shrub bed. This is how you plant and care for the attractive bedding shrubs.
Lupines (Lupinus) are a genus from the family Fabaceae. Nowadays, you will find 200 to 50 different species of the genus. The Lupine originally comes from North America. Both perennial and annual varieties are available. In the garden there are mainly cultivated forms of the shrub-lupine (Lupinus polyphyllus). The lupine impresses with its rapid growth and a conspicuous bloom that lasts from early summer to August. The numerous varieties of this plant not only brings a riot of colors to the cottage garden. The annual lupines can also be sown as green manure. In flower beds, the perennial shrub is a reliable filler because it also sows itself.
Appearance and Growth
Depending on the species, the lupines can grow up to 9.84 in height. The most commonly used garden lupine grows to a height of 31.49 to 47.24 inches, of which the wonderful, dense flower candles can be up to 19.68 inches. The butterfly-shaped flowers are arranged in terminal heads or ears and, depending on the variety, come in white, purple, pink, red or yellow, and even two-tone variants. The flowers open from late May to early August, always from the bottom of each candle. For this reason, the lupine primarily blooms throughout the summer. The foliage of the lupine is also quite ornamental. Each palm-shaped pinnate leaf consists of 9 to 17 lanceolate leaves.
Location and Soil
The lupine’s appeal in terms of growth and color intensity can be fully appreciated in open, sunny locations. In shaded locations, the willingness to flower decreases and they lose their stability. Lupines grow in any soil that is not too nutrient-rich and is lime-poor. However, if the soil is too calcareous, the leaves will turn yellow. Lupines do not tolerate waterlogging. A well-ventilated, medium-heavy to light soil is ideal.
Sowing and planting lupines
Those who want to sow annual lupines can sow the seeds directly into the flower bed in May. The perennial representatives should be planted in spring, as they often do not grow properly in fall. If you want to cultivate lupines in a container, you should choose a very small variety and a tall pot, as tall varieties can easily bend in the wind.
If necessary, you should support the flower stalks of the taller lupine varieties. Pruning immediately after flowering usually encourages re-flowering in summer. Full pruning of the plant often leads to complete failure. Slightly loosening the soil around the plant, especially after rain, helps the lupine with better flowering. Lupines shouldn't be fertilized too much, otherwise the plants become more susceptible to diseases and pests. Fertilizing with bone meal can, however, promote the stability of the stems. On the other hand, fertilizers with a high nitrogen content are completely unsuitable, because the additional nitrogen causes the roots to rot.
It is advisable to give lupines a "rejuvenation cut" about every three years: Divide up dug up rhizomes in spring and put the new shoots back in the garden.
Where to plant in the garden
The Russel hybrids (Lupinus polyphyllus) are particularly suitable for the perennial garden. Lupins grow well in small groups of three to ten plants in front of a hedge or group of trees. In addition to shrubs that bloom later, such as myrtle aster (Aster ericoides), the summer phlox (Phlox paniculata) or coneflower (Echinacea) also are quite attractive. In the cottage gardenthe perennial multi-leaf lupines exude their rural charm between daisies, poppies, irises and summer lilac. The West Country Lupins are a true wonder of color. The robust variety from England shines with beautiful luminosity. Varieties like ‘Masterpiece’ stand out because of their large inflorescences. The lupine does not lose any of its charm in the vase, and many varieties spread a pleasant fragrance.
Since lupine seeds have a high protein content, the seeds were processed and eaten by our ancestors. The blue lupine was even grown as a coffee substitute in farm gardens. Lupine seeds have been considered as food and medicine since ancient times. But take care while experimenting: The lupines growing in the garden are poisonous as a whole, because lupins contain large amounts of alkaloids.
In the feed and food industry, the seeds of specially grown, low-alkaloid varieties of the sweet lupines are used and processed into yoghurt, spreads, ice cream, milk, flour or even used as sausage and meat substitutes.
Lupins as green manure
Certain types of lupine are ideal for green manuring, especially if you want to deep fertilize the soil, enrich it with nitrogen or add organic fertilizer in the soil. Lupins are hardworking nitrogen collectors. There are so-called rhizobia on their roots, which store the nitrogen that the plant has absorbed from the soil in the root nodules. This can be used to improve the soil in the garden. It is advisable to sow narrow-leaved lupine (Lupinus angustifolius), yellow lupine (L. luteus) or white lupine (L. albus), especially when new flower beds are being planted. All three species not only enrich the soil with nitrogen, but are also deep-rooted – their tap roots penetrate up to 6.56 feet into the earth and can loosen up compacted layers.
As green manure, lupins are sown from April to August. When sowing, add algae lime or stone powder to the soil – this promotes the rhizobium. As lupines are winter-hardy, you can sow them after harvesting the vegetable patch. Cut the annual plants after winter at the latest and leave them as a layer of mulch. The dried plant remains should lay flat into the ground. This is how the nitrogen gets into the soil and is available to the plants planted thereafter. Valuable humus is also created from the rotting organic material of the lupines. Around four weeks later, the flower beds can be cultivated as desired.
Important Species and Varieties
Nowadays, numerous types and special varieties of lupine are commercially available. Numerous varieties were cultivated at the beginning of the 20th century by crossing the American perennial many-leaved lupine with other annual and perennial species. The variants by the English breeder George Russell (1857–1951) are still widespread today. The so-called lock series includes, for example, the varieties ‘Fräulein’ (white), ‘Kronleuchter’ (yellow) and ‘Edelknabe’ (carmine red). These reach heights of 31.49 to 39.37 inches and bloom for many weeks in bright as well as pastel colors.
The different colored varieties of dwarf garden lupins (Lupinus-Nanus-Russell hybrids) are much lower in height. They grow up to 19.65 to 23.62 inches in height and are suitable also as potted plants. In addition to these reliable shrubs, newer varieties are gaining popularity. These also come from an English nursery and are grouped under the name Westcountry series. Many of the tall, but at the same time stable lupins are two or more colored and thus the absolute stars in the shrub bed. Extravagant varieties such as Masterpiece ’and‘ Salmon Star ’are preferably surrounded by discreet companions such or lady’s mantle, so that they don't steal the show from the lupines.
In general, lupines propagate by sowing them from April to July. The seeds germinate better if you rub them and leave them to soak in water for 24 hours. If lupines are propagated by cuttings, the offspring have the same color as the parent plant flowers. To propagate cuttings in spring, cut off 1.96 to 3.93 inches long young shoots from the plant base and remove all but the top one or two leaves. To avoid the soft shoots from rotting, place them in loose substrate, for example expanded clay in pots. Half of the hardwood cutting height should be in soil and place them in a warm location which does not receive full sunlight and the humidity is constant and uniform. After four to six weeks, the hardwood cuttings with roots can be planted individually in potting soil. Then you just have to water the lupine offspring every now and then and plant it in the flower bed about six weeks later.
Diseases and Pests
The lupine is occasionally attacked by lupine aphids. This pest, introduced via Great Britain in the 1980s, usually occurs in large colonies and simply causes the lupines to tip over. If the infestation is low, the problem can be dealt with by spraying it off with a sharp jet of water. In the case of larger colonies, only insecticides can help. If young shoots of your lupine are dying off, necrotic spots appear on the leaf margins or cracks form on the stems and on older leaves, your plant is probably suffering from anthracnose. Unfortunately, the only thing that helps here is to remove the infected lupine. It can also be infested with powdery mildew. The fresh shoot of the lupine is also popular with snails.
Frequently Asked Questions
What are lupines?
Lupines are a genus of plants from the legume family and typical shrubs in the cottage or cottage garden. Some varieties are suitable for green manuring. The protein-containing seeds of specially grown varieties are processed into foods such as ice cream, coffee or meat substitutes in the food and feed industry.
Where does the lupine come from?
Lupines are originally from North America, but were introduced in the early 19th century. Brought to Europe, where they have since been found as wild shrubs.
Where does the lupine grow?
Lupines prefer a light or medium-heavy soil that should not be too rich in nutrients or lime-rich.
When can you sow lupines?
In May, the seeds of annual lupins are sown directly in the flower bed. Perennial species of the lupins are planted in the spring.
When can you plant lupines?
Perennial species of lupins are planted in spring to give them time to grow well.
How long do lupines bloom?
Lupines bloom from late May to early August, around four months.
When can you prune lupines?
If lupines are cut back immediately after flowering, you can look forward to re-flowering in summer. Radical pruning should be avoided, as the plants can perish.
Which lupines are edible?
Since lupines contain toxic alkaloids, the seeds must be soaked in brine for about 14 days before they can be eaten. The situation is different with the seeds of low-alkaloid varieties - so-called sweet lupins. These only have to be soaked for a day or two before they can be processed further.
Which foods contain lupine?
Lupines are found in a wide variety of foods. These are often intended to replace foods of animal origin. They can be found in gluten-free baking mixes or baked goods. But vegetarian patties, meat and sausage substitutes, milk, coffee and ice cream are now also made from lupine seeds.