How to Grow Japanese Knotweed (Japanese Bamboo) as an Ornamental

Not True Bamboo, But Bamboo-Like

Japanese knotweed (Reynoutria japonica), also called Japanese bamboo or Mexican bamboo, is an herbaceous perennial with raised nodes and hollow stems resembling bamboo. Fast-growing, tenacious spreader, considered invasive in many areas—but attractive and effective as a flowering border where contained.

Growing Steps

Step 1: Site Selection

Average to slightly acidic soil, full sun (shade-tolerant). Adapts to various conditions.

Step 2: Planting

Sow seeds under thin soil in early spring after last frost, or bury a root segment 4 inches deep.

Step 3: Watering

Keep soil moist but not wet. Somewhat drought-resistant but prefers wetlands/abundant water.

Step 4: Annual Cycle

Dies back yearly. Spreads and regrows naturally next season. Contain aggressively—rhizome barriers essential.

Only plant where spread can be strictly controlled. Check local invasive species regulations.