"Blue lupine" can refer to several species of lupines that produce blue-colored flowers. One common species is Lupinus perennis, also known as wild lupine or sundial lupine. Here's some information about it:

1. Description: Lupinus perennis is a native wildflower in North America, particularly in regions with well-drained sandy soils. It typically grows to a height of 3 to 4 feet and features palmately compound leaves with 7 to 11 leaflets. The flowers are arranged in dense, elongated clusters (racemes) and are usually blue, although they can also be purple, pink, or white. Each flower has a distinctive pea-like shape.

2. Growing Conditions: Blue lupine thrives in full sun to partial shade and well-drained soil. It is commonly found in open woodlands, prairies, and along roadsides. Lupines have a taproot system, allowing them to tolerate drought conditions once established. However, they may benefit from supplemental watering during dry spells, especially in hot climates.

3. Blooming Season: Blue lupine typically blooms in late spring to early summer, although the exact timing may vary depending on the climate and growing conditions. The flowers are attractive to bees, butterflies, and other pollinators, making them a valuable addition to pollinator gardens and naturalized areas.

4. Maintenance: Blue lupine is relatively low-maintenance and requires little care once established. It may self-seed and naturalize in suitable growing conditions. Deadheading spent flowers can encourage prolonged blooming and prevent self-seeding if desired. Lupines are also nitrogen-fixing plants, meaning they can improve soil fertility by converting atmospheric nitrogen into a form usable by plants.

5. Landscaping Uses: Blue lupine is well-suited for naturalistic landscapes, meadows, and cottage gardens. Its vibrant blue flowers and attractive foliage add color and texture to mixed perennial beds and borders. Lupines are also deer-resistant and drought-tolerant, making them suitable for xeriscaping and wildlife-friendly gardens.

Overall, blue lupine is a beautiful and versatile wildflower that adds color and charm to naturalistic landscapes and cottage gardens. With its easy-care nature and ability to attract pollinators, it's a valuable addition to any garden or landscape.