Butterfly bush. Fast growing shrub with arching stems and panicles of very fragrant, dark purple flowers in the summer. Height 3m. Spread 5m. Flowers from July to September. Full sun/partial shade. Well drained soil. Hardy. Attracts bees and butterflies.
Buddleja davidii ‘Black Knight’ is a fast-growing shrub known for its striking dark purple, fragrant flowers that attract bees and butterflies. Follow this detailed guide to ensure your Buddleja davidii ‘Black Knight’ thrives in your garden.
PLANTING and AFTERCARE GUIDE
Best Planting Time
Spring: The ideal time to plant Buddleja davidii ‘Black Knight’ is in spring. This allows the roots to establish before the peak growing season.
Autumn: Alternatively, early autumn is also suitable, giving the plant time to settle before winter dormancy.
Site Selection
Sunlight: Buddleja davidii ‘Black Knight’ flourishes in full sun but will tolerate partial shade. Aim for at least 6 hours of sunlight daily for optimal flowering.
Soil: Ensure the soil is well-drained. Waterlogged conditions can harm the roots. Improve heavy soil by incorporating organic matter such as compost or grit to enhance drainage.
Planting Instructions
Prepare the Hole: Dig a hole twice the width of the root ball and the same depth. This provides ample space for root expansion.
Soil Preparation: Mix compost into the soil to enrich it with nutrients and improve drainage.
Planting: Place the root ball into the hole, ensuring the top is level with the surrounding soil. Backfill gently, firming the soil to remove air pockets.
Watering: Water thoroughly after planting to help the soil settle and promote strong root establishment. Ensure good drainage to avoid waterlogging.
Watering Needs
Active Growth: Once established, Buddleja davidii ‘Black Knight’ is drought-tolerant but will benefit from occasional watering during prolonged dry periods. Let the soil dry slightly between waterings.
Dormancy: Reduce watering in winter when the plant is dormant, as excess moisture can damage the roots.
Feeding
Apply a balanced, slow-release fertiliser in early spring to support new growth.
A second feeding mid-summer can encourage more vibrant blooms and sustained growth.
Pruning
Spring Pruning: In early spring, prune Buddleja davidii ‘Black Knight’ hard to around 30cm above the ground. This encourages vigorous new growth and enhances flower production.
Deadheading: Remove spent flower panicles throughout the blooming season to extend flowering and keep the plant tidy.
Mulching
Apply a layer of organic mulch, such as bark chips or well-rotted compost, around the base in spring. Mulching helps retain moisture, suppress weeds, and regulate soil temperature.
Renew the mulch layer in late autumn to protect the roots from extreme temperature fluctuations.
Supporting the Plant
Buddleja davidii ‘Black Knight’ typically has sturdy stems, but in windy areas, consider staking young plants to provide additional support.
Final Tips
Buddleja davidii ‘Black Knight’ is a low-maintenance shrub that rewards you with stunning summer flowers and pollinator activity. By planting it in a sunny spot with well-drained soil and following these care tips, you’ll enjoy this beautiful shrub’s vibrant flowers and enticing fragrance from July to September. Include Buddleja davidii ‘Black Knight’ in your garden for a show-stopping display and to support local wildlife.
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Ruth B. (verified owner) –
The plants were healthy, arrived quickly and were well packaged. I will use this nursery again
Pam H. (verified owner) –