About Lupines

Over 200 different species of lupines exist.

Early summer typically finds the lupine (Lupinus spp.) showing off its upright flower spikes in shades of purple, blue, white or pink. Lupines are popular in English-styled cottage garden designs and make vibrant cut flowers for an indoor bouquet. Many of the garden varieties of lupines are complex hybrids of many different species of lupines. Modern garden lupines grow best where summers are cool, such as in U.S. Department of Agriculture hardiness zones 6 and colder, but many wild species grow well in warmer regions, too.

Geographical Distribution

Worldwide there are about 200 different species of lupines. They grow as annuals, perennials or semi-evergreen, semi-woody shrub-like plants. Generally speaking, they grow on dry, hilly grasslands and sunny openings of woodlands, alpine screes, coastal sand cliffs or upon riverbanks. Lupines are native to the lands surrounding the Mediterranean Sea as well as all across North, South and Central America.

Features

Lupines typical develop long taproots wherever they grow. Most develop short-stemmed, softly hairy leaves that are mid-green in color. The leaves radiate from the base, not on long stems. The foliage has lance-shaped leaflets that form an individual palmate or fan-like compound leaf. In late spring to early summer, upright flower spikes lined with many pea-like blossoms are displayed, attracting bees for pollination. The blossoms can be bi-colored, usually containing white with another color that is either lavender, yellow, blue, purple, pink or red-violet. Blossoms also can be solid in color. Seeds form and drop to germinate into new plants. Depending on species, a lupine plant is killed back by fall frosts, survives over the winter via its roots, or retains its foliage as a semi-evergreen.

Types

Many lupines have been traditionally grown as garden ornamentals. Annual lupines include Hartweg's lupine (Lupinus hartwegii), dwarf lupine (Lupinus nanus), European yellow lupine (Lupinus luteus), Andes lupine (Lupinus mutabilis), and the Texas bluebonnet (Lupinus texensis). Perennial types include the Washington lupine (Lupinus polyphyllus), wild lupine (Lupinus perennis) and Brewer's lupine (Lupinus breweri). Lupines that are semi- to fully evergreen and become somewhat shrub-like include the tree lupine (Lupinus arboreus) and silver bush lupine (Lupinus albifrons). Modern hybrid lupines typically have a common ancestry involving genes from either the Washington lupine or tree lupine if not both, according to Allan Armitage in "Herbaceous Perennial Plants." An example of a hybrid is called a "Russell lupine," named after the Englishman who first made the cross.

Cultivation

Grow lupines in any fertile soil that is crumbly and light in texture. Usually any sandy soil that drains freely with some organic matter is ideal. A slightly acidic soil is best (pH 6.0 to 7.0). Most lupines grow best in a full-sun exposure or partial shade where they get some direct sun rays for no less than four hours daily. Plants native to alpine regions need a grittier soil with organic matter, and any lupine with silvery foliage tends to fare better when the winters are not overly wet. Sow seeds of lupines in spring or autumn and nick the hard seed coat or soak the seed in water for 24 hours prior to planting. Many lupines are self-sown where they grow. Don't dig or disturb growing lupines because of their long taproot structures.

Concerns

If humidity is high or rainfall/irrigation too abundant, lupines tend to succumb to fungal and bacterial spots. Other problems include powdery mildew, rust, stem rot and Southern blight. Modern garden hybrids often do not grow as reliable perennials in regions with long, hot summers (USDA hardiness zones 7 and warmer) and will grow as annuals. Sow the seeds of such plants to enjoy lupines each year.

References

• "Herbaceous Perennial Plants"; Allan M. Armitage; 1989
• "A-Z Encyclopedia of Garden Plants"; Christopher Brickell and H. Marc Cathey, eds.; 2004