One of my favorite perennials is the lupine. They grow wild across Canada and parts of the United States. In urban gardens they’re short-lived perennials, particular about their sun exposure. Those in an open sunny bed in my yard lasted just two years, but lupines planted on the east side of my garden sheds lasted more than five years. The latter received afternoon shade. Both received moderate water and no fertilizer.
Lupine flowers are sweet pea shaped, and the flower spikes open dense blossoms from the bottom, moving upward. Spikes of flowers may rise to four feet, so plant at the back of your ornamental bed, although some gardeners plant them here and there in their dense cottage garden beds. Deadheading spent blossoms encourages more blooming, so plant where you can reach. Blossoms of wild lupines are usually blue or white, but domestic varieties have been bred to bloom pink, yellow or purple.
In 1930s England, George Russell set out to make lupines more interesting and more ornamental by crossing Lupinus polyphyllus with L.hartwegii. He produced very ornamental lupines, with two-toned blossoms that were an instant hit in the garden world.
Now “Russell lupines” are sold in plant centers worldwide, and are said to be native in British Columbia. If they’re not native, they’re Russell lupines gone wild.
Blue-flowered lupines known as bluebonnets are the state flower of Texas. Another common name for the flowers is Quaker bonnets. There are over 200 species, many producing edible beans. Those beans have been consumed in the Mediterranean area for at least 3000 years and in the Andes for over 6000 years.
As a food they’re high in fiber, protein, amino acids and antioxidants, low in calories and fat. Edible varieties of lupine contain isoflavones and alkaloids that must be removed through processing. For culinary uses, the plant is usually spelled “lupin” or “lupini.”
My “grow something new each year” this year is a row of lupini, (lupin beans) from Seeds from Italy. Most edible varieties are extremely bitter, and must be properly soaked or rinsed. Australians and some Germans have tried conventional breeding to produce sweeter lupin beans than the bitter ones.
All lupins or lupines are legumes, taking nitrogen out of the air and “fixing” it in the soil where plant roots can use it. Another benefit they provide is serving as a feeding resort for our favorite butterflies and other pollinators. Our summer may be too hot for them to thrive, since they grow best in cooler weather.
Seeds are hard and dense, requiring special treatment for germination and for consumption. For germinating all species of Lupinus, pour hot water over seeds and let them soak for three days. They should plump up, and then germinate in two weeks or longer, at a temperature of about 68 degrees F. For germination of lupine, I poured hot water over the beans and soaked them overnight.
The variety Lupinus lepidus may be more difficult to germinate. If they haven’t germinated in three or four weeks, Put them in the refrigerator (24 to 39 degrees F. for 12 weeks, then return to 68 degrees for germination. Or winter sow them, and let Mother Nature do the chill stratification. You can carefully transplant seedlings, but when they outgrow seedlinghood, they’re difficult to transplant because of their long taproots.
Grow in well-drained unimproved soil, not enriched by compost or fertilizers. Once established, fertilize with a high phosphorus fertilizer, the one with the higher middle number than the first or third numbers. A potential problem here is that mycorrhizae don’t thrive in high phosphorus conditions, so don’t apply a large amount.
Lupines are members of the Fabaceae family, and may be allergenic for people allergic to peanuts. Since they’re closely related to other old world beans, the fava beans (also members of the Fabaceae family), they might be deadly to those of Mediterranean ancestry who must avoid fava beans. . They’re said to be hardy to zone 5 (to minus 20 degrees F.), so might be winter sowable, like the fava bean.
Send garden questions to firstname.lastname@example.org or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.