Sawatch knotweed (Polygonum sawatchense)

Sawatch knotweed

Sawatch knotweed (Polygonum sawatchense) is an annual herb in the buckwheat family that is found throughout western North America. Like other flowering plants in the Polygonum family, this knotweed is known to attract the Purplish Copper Butterfly.

Scientific classification

Species

Sawatch knotweed (Polygonum sawatchense)

Pinks, cacti, and allies

Instantly identify plants with a snap

Snap a photo for instant plant ID, gaining quick insights on disease prevention, treatment, toxicity, care, uses, and symbolism, etc.

Download the App for Free

Annual

Lifespan

Herb

Plant Type

Spring, Summer

Bloom Time

50 cm

Plant Height

3 mm to 4 mm

Flower Size

White, Green, Purple

Flower Color

Deciduous

Leaf type

Culture

Interesting Facts

This plant was found in Philadelphia around 1910. It is a kind of rice field weed that is hard to remove because of its strong viability in wetlands, river banks, grasslands, moors and mudflats.

Get quick plant knowledge with a snap

Snap a photo for instant plant identification and learn about its name, symbolism, interesting facts, uses, and more.

Download the App for Free

Care Guide for Sawatch knotweed

Every week

Water

Full sun

Sunlight

20 - 35 ℃

Ideal Temperature

Water: Sawatch knotweed prefers consistent moisture and thrives with weekly watering to maintain health. While moderately drought-tolerant, it benefits from natural rainfall in outdoor cultivation. As an herbaceous perennial, adequate water during the growing season is essential for growth and resilience.

Fertilize: For sawatch knotweed, regular fertilization supports growth and blooms. Use balanced fertilizers during growth, switch to high nitrogen pre-season. Apply quarterly as recommended, adjusting for season. Avoid overfertilization to prevent root burn, and water before and after application for nutrient distribution. Ensure even spread around the base.

Pruning: Sawatch knotweed thrives with early to late spring pruning, focusing on removing dead stems to foster new growth and maintaining shape. Clean cuts are essential to prevent disease, while regular pruning enhances vitality, size management, and air circulation for a robust appearance.

Propagation: Sawatch knotweed is propagated by sowing fresh seeds for higher germination rates. Sow seeds shallowly in well-draining, fertile soil, keeping it consistently moist but not waterlogged. Adequate spacing fosters healthy growth, and once established, seedlings should be transplanted with minimal root disturbance.

Get tips and tricks for your plants.

Keep your plants happy and healthy with our guide to watering, lighting, feeding and more.

Download the App for Free

Learn More About Sawatch knotweed

Plant disease auto-diagnose & prevention

AI-powered plant doctor helps you diagnose plant problems in seconds.

Download the App for Free