Knotweed 'Blackfield' – Persicaria amplexicaulis ‘Blackfield’ | ↕10-25 cm | Ø9 cm

Knotweed ‘Blackfield’
Persicaria amplexicaulis ‘Blackfield’

Persicaria amplexicaulis ‘Blackfield’ is a striking, long-flowering perennial with deep dark red flower spikes that provide color from summer until well into autumn. The plant is strong, reliable, and ideal for natural, lush borders. A true eye-catcher in the garden.

Features and care:

Latin name: Persicaria amplexicaulis ‘Blackfield’
Dutch name: Knotweed ‘Blackfield’
Height: 10–25 cm (young plants)
Mature height: 80–120 cm
Width: 60–90 cm
Leaves: Large, fresh green, elongated, and slightly wavy
Flowers: Deep dark red, slender flower spikes
Flowering period: July to October
Growth habit: Upright, bushy, and very strong
Light requirement: Sun to light partial shade
Soil: Moist to moderately moist, rich in humus and well-draining
Moisture: Prefers a cool soil; does not tolerate prolonged drought
Pot size: Ø9 cm, ideal for group planting or as a solitary in a lush border
Pruning: After flowering, old flower spikes can be cut back for a neater appearance. Remove old stems in spring.
Watering: Water regularly during dry periods. A consistently moist soil promotes the best growth.
Fertilization: In spring, apply a layer of compost or organic fertilizer for vigorous growth.
Hardiness: Very hardy. The leaves die back in winter but regrow vigorously in spring.
Is Persicaria amplexicaulis ‘Blackfield’ toxic? No, this plant is not toxic to humans, dogs, or cats.
Why choose Persicaria amplexicaulis ‘Blackfield’?

• Deep dark red flower spikes for a powerful color accent
• Very long flowering, lasting well into autumn
• Strong, reliable, and low maintenance
• Perfect for natural, lush borders
• Attractive to bees and butterflies