There are hundreds of lupine species, many of them native to the southwestern U.S.; they're found in a wide range of habitats, from alpine rocks to beach sand. Leaves are divided into many leaflets (like fingers of a hand). Sweet peashaped flowers are borne in dense spikes at stem ends. Most lupines take poor soil, but hybrids prefer rich, slightly acidic, well-drained soil.
L. hartwegii. Annual. Zones US, MS, LS, CS, TS; USDA 6-11. Native to Mexico. Grows 13 ft. tall, with flowers in shades of blue, white, and pink. Easy to grow from seed sown in place in spring for summer bloom. Moderate water.
L. havardii, L. subcarnosus, L. texensis. BLUEBONNET. Annuals. Zones MS, LS, CS; USDA 7-9. All require poor, dry soil to survive; with regular flower border pampering, these Texas roadside flowers rot. For small areas, set out plants in fall to flower the following April. For meadows, scatter treated seeds (see Help in the Nick of Time, at right) onto moist ground in September and lightly rake the soil surface; keep soil moist only until seeds germinate. Replant or resow each fall for several years; seed from current year's flowers does not germinate reliably to produce next spring's floral display. Adequate fall and winter rains are necessary to produce spectacular spring show.
L. havardii, Big Bend bluebonnet, is the tallest bluebonnet, reaching 34 ft. high; its flowers are very deep blue. L. subcarnosus, the state flower of Texas, grows to 1 ft. tall, has sky-blue flowers with a tinge of white. L. texensis, Texas bluebonnet, to 1 ft. tall, has dark blue flowers with a white eye that turns red after pollen is no longer viable, signaling bees not to visit plant.
L. hybrids. Perennials often treated as annuals. Zone US; USDA 6. To 45 ft. tall, 2 ft. wide. These English-bred hybrid groups are descended from plants native to western America. Their dislike of summer heat and humidity makes them hard to grow in the South, even in the Upper South. Plant them in fall, be grateful for the flowers they produce the following yearand don't expect more than that. Self-sown seedlings won't resemble parents. Regular water.
Russell hybridsthe classic lupinesbloom during late spring or early summer, bearing tall flower spikes in white, cream, yellow, pink, red, orange, blue, purple, or bicolors. Little Lulu and Minarette are small strainsto 1 ft. high and wide. All Russell hybrids tend to be short lived. They are prone to powdery mildew, so provide good air circulation. Grow from seed or buy nursery plants.
New Generation hybrids have all the merits of the Russell hybrids (from which they were developed), but they are sturdier (needing no staking) and mildew resistant. They also come in a wider range of brighter, more intense colors, including interesting bicolors such as yellow-and-orange combinations. Bloom period is longer, too. Sold as seedling plants.
L. perennis. WILD LUPINE. Perennial. Zones US, MS, LS, CS; USDA 6-9. Native to eastern U.S. To 2 ft. high, with purple flowers in late spring or early summer. Regular water.