Lupines for all reasons

Flower & Garden Magazine, May-June, 1997 by Jacey Holden

In the West, 1993 was the year of the lupine. Spurred by a wet winter that followed seven years of drought, nature responded with a wildflower display unrivaled in 60 years. In the eastern Sierra Nevada mountains, several species of lupine could be spotted on a single hillside, following various microclimates down the slope from the dry, windswept crest to the moist meadows at the base. This abundance brought plant enthusiasts of every persuasion to revel in the once-in-a-lifetime spectacle of floral flamboyance.

Named after the Latin word for wolf, Lupinus species were once thought to rob the land of its mineral food and to create the barren, sandy soil on which they commonly flourished. Biologists now recognize lupines as pioneer plants that are specifically adapted to colonize and thrive in severe growing conditions. Lupines are esteemed as glorious wildflowers, stately border perennials and colorful garden annuals. One species, Lupinus albus, has demonstrated its value as a food for humans, animals and even the soil itself.

America's West boasts the largest collection of lupines in the world. From Alaska to Chile, nearly 200 species of lupine carpet hillsides and roadsides in oceans of lavender-blue. Although the largest concentration of wild lupines is in the West, there is a scattering of species between the Rocky Mountains and the Atlantic coast, and a few species are found in the rest of the world.

Gardeners wishing to try wild lupines in their borders can order seeds from companies specializing in wildflowers. The most frequently offered species:

* Lupinus arboreus, a 6-foot perennial shrub, hardy to Zone 8, with flowers that are usually lemon yellow;

* L. texensis and L. subcarnosus, the famed Texas bluebonnets, rich blue-and-white annuals;

* L. nanus, a self-sowing California annual that combines well with California poppies (Eschscholzia californica) to blanket waste areas and for erosion control; and

* L. perennis, a deep blue perennial lupine that thrives throughout much of the United States in full sun and dry, well-drained soil.

Derived from the wild species, hybrid garden lupines have been bred specifically for their ornamental value. The most common varieties are the Russell hybrids developed by Yorkshire, England, gardener George Russell. Russell worked tirelessly with lupines from 1911 until 1937, when the results of his efforts were exhibited at the Royal Horticultural Society. He was then 86 years old. The Russell hybrids are large, 4- to 5-foot plants with long, dense flower spikes in a rainbow of colors and bicolors. Placed at the back of the border, they give a bold vertical accent in May and June, yet their unattractive late-summer foliage is hidden from view after the display is over. These hybrid lupines are perennials, but in harsh climates are not reliably long-lived.

Although the Russell hybrids are still the most popular garden lupines, other hybrids are available. Many people consider the dwarf forms, such as 'Dwarf Lulu' and 'Minarette,' superior to the Russell hybrids because of their compact stature and full range of color.

Lupines need a well-drained, neutral to slightly acid soil and dislike soggy conditions. Many of the native species are extremely tolerant of drought and poor soil. Hardy to Zone 3, hybrid lupines prefer a richer, moister soil and flourish where drainage is good and the climate is not too hot.

Because they have a long taproot that resents disturbance, lupines are best grown from seeds that are sown where they are to remain. The perennial hybrids can be given a head start in individual containers indoors so long as they are transplanted to the garden while still small. The seeds have a hard coat that requires nicking to speed germination. Once established, little care is needed except to stake the tall varieties and watch for aphids.

Although lupines are best known today for their ornamental qualities, certain species have a long history as a source of nourishment. Grain lupin, sometimes called "lupin beans," has been cultivated for more than 3,000 years as a minor food crop in South America and some Mediterranean countries. (The "e" is often dropped from the end of the word "lupine" to distinguish those that are used as an edible grain.) Lupin seeds have been discovered enclosed in a pharaoh's tomb inside a 6,000-year-old pyramid. In 400 B.C., Hippocrates described lupin as a favorite soil-enriching plant that had a non-gaseous quality when used as a food.

White-flowered Lupinus albus, a European species used in producing lupin flour, is also valuable as a soil-enriching cover crop. The seeds of L. albus should be inoculated before planting with the nitrogen-fixing bacteria Bradyrhizobia lupini. The bacteria removes nitrogen from the air and deposits it in tiny nodules on the roots, providing the plants with nourishment that otherwise would be unavailable to them. Additionally, the long taproot of L. albus acts as a biological "plow," helping to open hard soil.

Until recently, seed of Lupinus albus was available through several catalogs specializing in cover crops and other agricultural seeds. It has become increasingly difficult to locate, although some farm supply stores still sell it.