Black Knight Butterfly Bush (Buddleja davidii ‘Black Knight’) is a popular cultivar of butterfly bush known for its deep, violet purple spikes of flowers. The blooms of butterfly bushes are well known to attract butterflies and other pollinators. Here's why the Black Knight Butterfly Bush is the perfect addition to your landscape:

Flowers: This cultivar is valued for its rich purple color. The flower spikes are dense and appear from midsummer into fall, attracting butterflies and other pollinators. The dark, violet-like color beautifully contrasts brighter blooms in the landscape. 

Foliage: Black Knight butterfly bush has gray-green foliage that provides a nice backdrop to its purple spikes. The leaves are lance-shaped and add to the overall attractiveness of the plant.

Size: Black Knight butterfly bushes can reach a height of around 6 to 8 feet, with a similar spread. They are generally fast growing and have an upright, arching growth habit.

Sunlight Requirements: Butterfly bushes, including Black Knight, thrive in full sun. Adequate sunlight exposure ensures vigorous growth and abundant flowering.

Soil and Watering: These plants can thrive in various soil types as long as the soil is moderately fertile and well-draining. Regular watering is beneficial, especially during dry periods, to encourage healthy growth and flowering.

Hardiness: Black Knight butterfly bush is generally hardy in USDA zones 5 to 9, making it adaptable to a range of climates.

Maintenance: Prune Black Knight in the early spring after new growth emerges. Make your cuts just above where big, healthy leaf buds have formed. It can take several weeks into spring for new growth to show up - be patient and resist the urge to cut them back too early.

Landscape Use: Butterfly bushes are a popular choice for mixed landscape beds and are often used in pollinator gardens. They make an excellent addition to any landscape that has full sun exposure.

Overall, Black Knight Butterfly Bush is a favorite among gardeners for its attractive flowers, wildlife value, and ease of care. Black Knight is a wonderful addition to any space and will stand out as a garden favorite year after year.