A member of the bean family, the lupine (Lupinus) genus contains several hundred species of flowering plants, many of which can be seen growing in abundance in the wild throughout the Americas, Africa and the Mediterranean. Lupines can be grown in many regions throughout the United States.
Lupines are characterized by their tall stalks of pea-like blooms and their distinct leaves, which are usually a light green covered with fine, silvery hairs. The leaves have an unusual, palm-like shape that helps to make the plant recognizable. Lupines are upright, usually growing to be about 3 feet tall, although some shrub species may grow to be much taller. The flowers are often thought of as being blue or purple, though they may also be pink or white.
Lupines are native to South America, parts of the Western and Southern United States, Canada, Africa and in the areas of the Mediterranean. They have naturalized throughout much of the United States, and in Europe they can be found growing as far north as Norway. The desert lupine (Lupinus sparsiflorus), also called Coulter's lupin, grows along desert roadsides and mesas throughout the Mojave, Chihuahua and Sonoran deserts. The Arizona lupine (Lupinus arizonicus) can also be found in the desert.
Hardy lupine species like the common perennial lupine (Lupinus perennis) will grow just about anywhere in the United States. Many species can be seen growing along roadsides doing fine on their own with no care at all. The Russel lupine (Lupinus Russell Hybrids), which contains many colorful cultivars, is slightly pickier and will only thrive in USDA Zones 4 to 8. Lupines in general prefer full sunlight and a sandy, well-draining soil that's slightly acidic.
Lupines in the home garden may have problems with powdery or downy mildew, rust, fungal stem rot, foliage rot or spots, and Southern blight. Avoid watering the plant too much, especially during late autumn and winter. Keep water off the leaves to prevent fungal rot or disease from forming. Mildly infected lupine leaves can be plucked off and thrown away to help keep the problem from spreading. In general however, lupines are quite healthy and hardy plants.
The name "lupinus" means "of wolves," a reference to an outdated believe that lupines hungrily drained nutrients from the soils they were planted in. Lupines actually enhance the soil however, providing valuable nitrogen. The flowers of the lupine plant are often called "bonnets," as the flowers have a hooded appearance. The brilliant royal blue state flower of Texas, the Texas Bluebonnet (Lupinus texensis) is actually a species of lupine. The plant can be found throughout the state growing as a wildflower.