Prostrate knotweed has spread as a weed to almost all temperate locations from its native habitat of Eurasia. It is considered invasive or an agricultural weed in 3 states. It readily establishes a persistent seedbank, with individual plants able to produce thousands of seeds that can last several years. Prostrate knotweed has been used as groundcover and cultivated as a dye; it has also been found to suppress other weeds and kill potato pathogens. However, it can also have synergistic effects or acts as an alternative host for crop pathogens and pests. Mowing is generally ineffective due to its matting growth pattern, but a combination of herbicide and other techniques including tilling, polarization, undersowing, and plowing can effectively control prostrate knotweed.

The best time to remove weeds is before their flowering and fructification, otherwise controlling them can be very difficult. After they have flowered and fructified, their seeds can spread very fast, and hence, the weeds should be removed more often and precautions should be taken in advance in the following year. Mulching: During the seed stage, covering the soil with sawdust, straw or black mulches can effectively inhibit seed germination and the growth of seedlings. In the winter or spring, this method is often used to inhibit the seeds in the soil from germinating. If the weeds have already flowered and fructified, then the method can also be used to prevent more seeds from falling into the soil. Pulling out: Wear gloves or use tools to remove weeds before their fructification. If the soil is too dry, then water the soil thoroughly to make it softer, which can help to remove the root systems of the weeds. After that, deep tillage can be adopted to remove bits of weed roots left in the ground. This method works particularly well for weeds that are low-growing or in their seedling stages. Mowing: Mowing weeds before their fructification can effectively control their spread. Especially for annual weeds, frequent mowing can inhibit their growth and fructification, and thus can remove them effectively within the year. Ploughing: Be sure to plough and pull out all roots of perennial weeds before planting. The roots should be discarded, exposed to the sun for a long time, or buried deep. You can also use the roots to make organic fertilizer and compost the weeds. The probability of its invasion can be reduced by planting crops in autumn. Its growth can be inhibited effectively by using herbicide 2-3 weeks before sowing. Note: When removing weeds, especially those which are toxic, thorny and have allergenic sap, be sure to wear gloves and avoid direct contact with them. When removing weeds during their bloom time, be sure to wear special masks to prevent pollen allergy.