How to Grow Lupinus Plants

Guide to Growing Lupin, Lupine, and Bluebonnet

Lupinus plant reach from 30 cm to 1.5 m (1 to 5 feet) in height, depending upon species and variety.

They have stiff erect spikes that carry pea like flowers, these grow in racemes.

Lupin flowers come in a variety of colours including purple, blue, pink, white and yellow.

Lupin flowers
Lupinus 'Thomas Church' by Anniesannuals.

The perennial varieties of Lupinus come into bloom in the summer, whilst annual varieties will flower about two months after being sown.

Lupinus argenteus
Lupinus argenteus by Matt Lavin.

Some common names for Lupinus plants include Lupin, Lupine, Bluebonnet, and Texas Bluebonnet.

Commonly Grown Lupinus Species

Lupinus perennis

Lupinus perennis
Lupinus perennis (Wild Lupine / Wild Perennial Lupine / Sundial Lupine), photograph by Aaron Carlson; CC.

Lupinus polyphyllus

Lupinus polyphyllus
Lupinus polyphyllus (Large Leaved Lupine, Russell Lupin), picture by Bernard Spragg. NZ; CC.

Lupinus Growing and Care Guide

Common Names: Lupin, Lupine, Bluebonnet, Quaker Bonnet. Genus contains over 600 species.
Life Cycle: Half hardy annual, hardy annual. Hardy perennial.
Height: 12 to 60 inches (30 to 150 cm); shrubs/tree up to 120/310 inches (300/800 cm).
Native: Mediterranean, Americas, Africa.
Growing Region: Zones 1 to 9. As a perennial in zones 4 to 9.
Flowers: Annual: spring or summer or autumn; dependent on when sown and species. Perennial: summer.
Flower Details: Purple, blue, violet, yellow, white, pink. Peaflower-like. Open whorls. Spikes. Racemes.
Foliage: Green to greyish-green. Silvery hairs. Palm-like or single leaflet.

Sow Outside: 1/8 inch (3 mm).
Annual: before last frost. Spacing 10 to 12 inches (25 to 30 cm).
Perennial: before last frost or in autumn. Spacing 12 to 40 inches (30 to 100 cm).
Sow Inside: Use peat pots. Soak overnight in hand temperature water or chip seeds. Germination time: two to nine weeks. Temperature 60 to 65°F (16 to 18°C). Seven or eight weeks before expected last frost. Transplant outdoors following the last frost or in autumn.
Requirements: Full sunlight or light shade. Good drainage. Soil pH 5.5 to 7. Moist soil. Regular watering. Deadhead. Propagate: perennials can be divided or cut in the spring.
Family: Fabaceae.
Miscellaneous: Lupins are able to fix their own nitrogen and growing them enriches soil. This makes them an ideal plant to grow close to hungry vegetables such as pumpkins, spinach, and cucumber.

How to Grow Lupin, and other Lupinus plants in the Garden

Annual varieties of Lupinus should be sown following the last frost. The perennial varieties can be sown in either autumn or just before the last frost of spring.

The Lupin seeds should be planted at a depth of about 3 mm (1/8th inch), and can grow in either a sunny or partially shaded part of the garden that has good drainage.

Lupins prefer to grow in a moist soil that is slightly acidic to neutral (pH 5.5 to 7).

When starting to grow Lupins indoors for later transplanting, then this process should be initiated about eight weeks in advance.

The germination of lupin seeds can take from two to eight weeks.

First the lupin seeds should be chipped and soaked for a day in warm water. They should then be incubated at about 12 to 18 degrees centigrade (54 to 64°F).

Once ready, Lupinus seedlings should be transplanted in the garden with a spacing of 30 cm (12 inches; annuals) or from 30 to 90 cm (12 to 36 inches; small to large perennial Lupinus).

Caring for Lupins, Lupine - Lupinus

Once established Lupinus plants are fairly easy to look after. They require regular watering, and the spent Lupin flowers should be dead headed regularly.

It is best to feed them with a fertilizer rich in phosphorous and low in nitrogen.

When growing perennials, cut the flower stalks down to the base once the flowering season is over.

If you require more perennial Lupinus plants, then they can be propagated by division or from cuttings in the spring.

Common Questions

How many members does the Lupinus genus have?

The Lupinus genus is large, containing over 200 species. These include the beautiful Lupine flowers, known for their tall, showy flower spikes.

Do members of Lupinus make a good garden or landscaping plant?

Yes, Lupinus can be wonderful in gardens or landscapes. They have impressive flower spikes and can help enrich the soil due to their nitrogen-fixing abilities.

Which Lupinus species are most frequently grown by gardeners?

Some commonly grown species include Lupinus perennis (Wild Lupine), Lupinus polyphyllus (Bigleaf Lupine), and Lupinus arboreus (Yellow Bush Lupine).

Are members of the Lupinus plant genus fragrant?

Some species of Lupinus, such as Lupinus perennis, have a mild, sweet fragrance, particularly in the evening.

What is the perfect location to grow Lupinus?

Lupinus prefers a sunny location with well-drained soil. It's a great choice for borders, wildflower gardens, or any area with poor, sandy soil.

Is Lupinus invasive in the USA, if so in which states?

Some non-native Lupinus species can be invasive in certain regions, particularly in the Pacific Northwest. However, native species like Lupinus perennis are not.

How do I remove Lupinus plants from my garden?

To remove Lupinus, you'll need to dig out the entire plant, including its deep taproot. Be sure to remove new seedlings promptly to prevent spreading.

Summary

The Lupinus genus, belonging to the Fabaceae family, consists of annual and perennial plants native to the Americas. Known for their distinctive leaf shape and tall, spiky flowers, these plants are often used in borders and wildflower gardens, commonly referred to as lupines.

Lupinus enjoys full sun and well-drained, slightly acidic soil. Regular watering is necessary for optimal growth. Propagation is typically achieved through seeds, generally sown in the spring.

I hope that you enjoyed this guide on how to grow Lupinus plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Acacia melanoxylon, Harlequin Flower, and Trigonella plants.