2020年2月24日 · Japanese knotweed (Fallopia japonica) is an invasive perennial and noxious weed in PA. This article will assist with identification and provides recommendations for control, including a management calendar and treatment and timing table.

2024年7月23日 · There are several approaches to treating Japanese knotweed. While you can try natural methods such as smothering, cutting, and digging of smaller and younger plants, you will likely need an herbicide for Japanese knotweed, especially if the plant has become established.

Cutting Japanese knotweed has been tested with minimal effect at permanently removing plant patches. The same underground portion of the plant that prevents pulling as an option also supports sprouting and growth each spring after cutting the previous year. Disposal is also an issue when knotweed has been excavated or cut. This is Class I invasive

Knotweed plants may be controlled by application of a systemic herbicide containing glyphosate or triclopyr to the actively growing plants. Cut or break stems in early summer, then apply herbicide spray to the regrowing shoots in late summer. Cutting should be timed so that plants do not exceed three feet in height when sprayed.

Cutting alone is not an effective suppression approach. However, cutting prior to an herbicide application can be very helpful. If you wait until about June 1 to cut, and wait 8 weeks to treat, you will find that the knotweed regrowth is much shorter than when it was cut. Typically, knotweed regrows 2 to 4 feet tall.

Prevention is key: early detection and rapid response are the most effective means of Japanese knotweed management. MECHANICAL CONTROL: Cut plants with pruners or loppers three times per year, in May or early June, mid-July, and late August before flowers appear.

Japanese knotweed (Fallopia japonica syn. Polygonum cuspi-datum), an herbaceous perennial member of the buckwheat family, was introduced from East Asia in the late 1800s as an ornamental and to stabilize streambanks. Knotweed is a highly successful invader of wetlands, stream corridors, forest edges, and drainage ditches across the country.

2025年1月14日 · 2. Cut Back and Burn. Another option that won’t fully eradicate the plant but can contain it a bit is to cut it back in the spring and fall and burn it. Be careful as trying to remove Japanese knotweed with fire can result in a stronger thicket that refuses to budget. The roots will grow deeper and stronger over time.

Typically, knotweed regrows 2- to 5-ft tall. This cutting also reduces rhizome growth as the plant has to expend its energy to regrow a canopy instead of expanding its network of rhizomes. When knotweed is growing near water, cutting is useful because it is easier to treat the shorter regrowth without getting spray solution into the water.