Wildflower watchers everywhere celebrate when springtime lupines come into bloom, heralding the flowers' appearance with tours and festivals from Maine to California.
Get to Know Lupines
Lupinus plants are members of the pea family, Fabaceae, and like peas, the plants are capable of fixing nitrogen in the soil. If the growing conditions are right, lupine flowers are equally at home in the garden or on the side of the road.
Lupines bloom over a two-month period, which can range from May to July, depending on the variety and the growing zone.
While Blue Bonnet generally refers to the annual lupine, perennial lupines return each year in growing zones 3-7. Lupines can grow up to five feet tall, with flower spikes as long as 18 inches long.
How to Plant Lupines
Lupines need neutral to slightly acidic soil, although they can grow in very acidic soil conditions. Lupines don’t need rich loam, but it’s important to grow the plants in very well-draining soil to avoid root rot. Sandy soil conditions and poor rocky soil promote the growth of the lupine’s deep tap root.
Starting lupines from seed is an economical way to get a showy flower garden the following season. The seed coat is tough, and seeds have a better germination rate if you nick the seed coat or soak them in water overnight. Plant them about ¼ inch deep outdoors in a permanent area that receives full sun, as they do not transplant well.
Expect germination in 14-30 days.
Although lupines demand good drainage, they also like regular irrigation, so provide the equivalent of one inch of rain each week if conditions are dry. Lupines don’t require fertilization, and in fact, too much fertilizer can encourage excess foliage growth at the expense of blooms.
Lupine Design Tips
Lupines are a welcome addition to wildflower gardens and meadows, but they are also well-behaved plants that adapt to the perennial border or cottage garden. Grow enough lupines for the vase, as their stiff hollow stems keep the flower spikes erect in arrangements. Cut the flowers when about ¾ of the flowerets are open for the longest lasting arrangement.
The dense floral spikes of lupines may grace your flower garden in shades of purple, pink, red, white, and yellow. The foliage resembles palm leaves, with seven to ten leaflet segments each.
Although rainbow hybrid lupine seed mixes are the most popular commercially available lupine, the original blue strain is the hardiest. Over time, the blue lupines in a rainbow mix will persist and perennialize, while the less adaptable colors die out.
- Russell mixed colors: Bred in 1937 and naturalized in many areas, this hybrid rainbow and bicolor mixture is the foundation for all new cultivars
- Lupinus polyphyllus: The species sold in wildflower mixtures; all blue flowers
- Gallery series: Dense flower spikes on a compact plant, growing no more than two feet tall