The lupine (Lupinus) produces large flower spikes that range in size from 1 to 4 feet in height. The blossoms appear as crowded racemes in shades of pink, blue, purple, yellow, white and lavender. A hardy perennial, the lupine offers ease of growth. About 300 species of lupine and numerous hybrids are available, according to the Purdue University. The plant grows native throughout most of the United States but is seriously threatened in many states.
Loosen the soil to a depth of 20 inches prior to planting and add peat moss and aged manure. The lupine plant grows well in soil that feels crumbly to the touch with organic matter. The plant prefers partial shade but will tolerate full sun in areas that do not have intensely hot summers
Apply 2 to 3 inches of mulch around the base of the lupine to help keep the soil moist and reduce weed growth. The lupine does not tolerate extremely hot weather conditions well and will easily wilt. The mulch helps keep the plant's root system cool.
Lupine thrives in moist, well-draining soil conditions with high organic content but it will also grow in sandy soils. Keep the soil evenly moist for best growth and flowering. The lupine does not tolerate periods of drought well and will easily wilt. Apply at least 1 inch of water per week if there is not ample rainfall. Avoid getting the flower spikes wet when watering or they will easily bend to the ground under the weight. Use a drip irrigation system or a soaker hose to water the plant.
Apply 2 to 3 inches of aged manure mixed with 25 percent bone meal around the base of the lupine plant in the spring. During the summer fertilize monthly using a water-soluble fertilizer. Follow the directions on the label for application instructions.
Transplanting and Division
Older established lupine are difficult to transplant due to the plant's extremely long tap root which often measures over 2 feet in length. Seeds are produced following flowering. The seeds appear in pods that contain 10 to 20 seeds. The lupine plant easily spreads using seeds and the young plants transplant easily. Divide the young plants away from the established parent plant in the early fall, being careful not to disturb the parent plant.