Planting Black Knight Butterfly Bush: A Complete Guide

The black knight butterfly bush (Buddleia davidii ‘Black Knight’) is a beautiful addition to any garden. Its nearly black purple flowers that resemble lilacs provide visual interest from midsummer to fall. This butterfly bush attracts pollinators like butterflies and hummingbirds.

If you want to grow this bush in your own yard, proper planting is key Follow this complete guide to successfully plant black knight butterfly bushes.

When to Plant Black Knight Butterfly Bushes

Spring is the ideal time to plant butterfly bushes. Aim to plant in late spring after the last frost date for your area. This gives the new shrub time to establish roots before winter arrives.

You can also plant in early fall But spring planted bushes will likely grow larger their first year compared to fall since they have the full growing season,

Choosing the Right Location

Selecting the optimal spot in your yard is an important first step. Here are the ideal conditions for your black knight:

• Full sun: Butterfly bushes thrive in full sun. Choose a location that receives at least 6-8 hours of direct sunlight daily. Morning sun is preferable to hot afternoon sun.

• Well-draining soil: Avoid planting in heavy clay or soggy soil. Well-draining loam enriched with compost is ideal.

• Air circulation: Allow adequate space between shrubs for air to circulate. Poor air flow encourages fungal diseases.

• Accessible: Plant somewhere you can easily reach to prune and care for the bush. An island bed or border works well.

Preparing the Soil

Preparing the ground before planting encourages fast root growth and healthy bushes. Follow these tips:

• Loosen compacted soil and break up large clumps, Till to a depth of 8-12 inches

• Mix in 2-4 inches of aged compost or well-rotted manure. This adds nutrients and improves drainage.

• Test the pH. Butterfly bushes prefer slightly acidic to neutral soil between 5.5-7.0. Adjust as needed.

• Rake and level the area. Remove weeds, rocks and debris that could impede growth.

• Consider planting on a slight mound if drainage is poor. Mounding soil improves elevation.

Planting Black Knight Butterfly Bushes

Once your soil is prepped, it’s time to plant. Follow these steps:

• Dig each hole 2-3 times wider than the root ball but no deeper. The top should sit level with the ground.

• For heavy clay soil, mix in sand, peat moss or small rocks to improve drainage.

• Carefully remove from containers. Gently loosen circled roots.

• Place in holes and backfill with native soil. Tamp down lightly but avoid compacting tightly.

• Water thoroughly until soaked. Let excess water drain.

• Spread 2-3 inches of mulch around bases leaving space near stems.

• Stake bushes for support if needed. Attach loose tie material that won’t rub or bind.

Initial Care and Maintenance

Be diligent about care and upkeep the first year for strong establishment:

• Watering: Water thoroughly 1-2 times per week during the first year, more in hot weather. Provide 1-1.5 inches per week.

• Weeding: Keep nearby weeds pulled to reduce competition for water and nutrients.

• Fertilizing: Use a balanced organic fertilizer or slow-release granular fertilizer once in early spring.

• Pruning: In late winter/early spring, prune back to 6-12 inches for shaping. Remove dead or damaged branches anytime.

• Pest control: Inspect frequently and use organic methods to control aphids, mites, scales or other pests. Remove diseased foliage immediately.

Ongoing Care

Once established, black knight butterfly bushes are relatively easy to care for:

• Water: Water during extended dry periods after the first year. Provide 1 inch per week.

• Fertilize: Fertilize each spring using an organic or slow-release product. Discontinue by mid-August.

• Prune: Prune new shoots back by at least 1/3 each spring to control size and encourage blooms.

• Protect: Mulch over the root zone in very cold winters. Avoid mounding mulch on stems.

• Pest control: Watch for common butterfly bush pests like aphids. Control with organic sprays.

• Deadhead: Remove spent flower heads to encourage more blooms.

With the proper planting and care, black knight butterfly bushes will thrive and add stunning color to your landscape for years to come. The sweet blooms will also attract beautiful butterflies and hummingbirds to your garden.

Troubleshooting Common Problems

Even when planted and cared for correctly, issues can sometimes arise. Here are some potential problems and solutions:

• Few or no flowers: This is often due to too much nitrogen fertilizer or improper pruning. Use a balanced fertilizer and prune flowered stems in spring.

• Leaf spot: Leaf spot fungal disease causes small brown spots. Improve air flow and avoid wetting foliage. Remove and destroy affected leaves.

• Wilting: Overwatering, underwatering, diseases or pests can cause wilting. Check soil moisture, improve drainage, treat diseases/pests.

• Webbing: If you notice webs, spider mites may be the culprit. Knock them off with a strong spray of water and apply insecticidal soap.

• White powder: Powdery mildew fungal disease is common. Apply neem oil or a fungicide labeled for this disease. Avoid wetting leaves.

Propagating Black Knight Butterfly Bushes

You can propagate new butterfly bushes from:

• Cuttings: Take 4-6 inch cuttings from vigorous shoots after flowering ends. Dip in rooting hormone and plant in potting mix. Mist often until rooted.

• Divisions: In early spring, dig up mature plants and divide the root ball with a shovel or knife. Replant divisions.

• Seeds: Collect seeds in fall from spent flowers. Start indoors 6-8 weeks before your last frost. Transplant outside after hardening off.

Alternative Plants to Black Knight Butterfly Bush

Here are a few alternative plants with similar traits if you want to consider other options:

• Blazing star (Liatris spicata) – purple spikes, attracts butterflies
• Caryopteris x clandonensis – blue flowers, likes sun
• Rose of sharon (Hibiscus syriacus) – semi-tropical, flowers through summer
• Ninebark (Physocarpus opulifolius) – red/purple foliage, hardy shrub
• Hyssop (Agastache) – spiky purple blooms, fragrant foliage

With mesmerizing dark purple blooms and an ability to attract pollinators, black knight butterfly bushes make an exceptional addition to gardens. Follow this guide for the ideal timing, location, soil preparation and care for successfully growing this beautiful butterfly bush. A small investment of time and care will allow you to enjoy their stunning floral display for years to come.