Polygonum oxyspermum subsp. oxyspermum
Polygonum oxyspermum subsp. oxyspermum, or Sharp-fruited Knotweed, is an annual ornamental plant that thrives in full sun and requires medium water. It grows to a height of 0.2–0.6 meters and is suitable for USDA zones 3–9. It blooms in white, pink, and red from June to September and prefers a variety of soil types including clay, sandy, loamy, chalky, and peaty. This plant attracts pollinators.
Light
Full sun
Watering
Medium water
Soil
Clay, Sandy, Loamy, Chalky, Peaty
Height
0.2–0.6 m
Spread
0.3–0.5 m
Zones
3–9
Flower colors
Plant in well-drained soil in a location that receives full sun. Water moderately, allowing the soil to dry slightly between waterings. Deadhead spent blooms to encourage continuous flowering. As an annual, it completes its life cycle in one season.