Hi there, we discovered that we have knotweed in the yard of our new home. We’d like to hire a professional to excavate, remove rhizomes and put down barriers. Can you recommend any experts in the Toronto area? Thanks very much.
Thank you for contacting the Toronto Master Gardeners. While we are more than happy to give horticultural advice, we cannot recommend specific product or service providers. May we suggest the Landscape Ontario website, where you will find a listing of their member companies that may offer the services you require. Good luck!
If you wish to tackle this problem yourself here is our answer to a similar posting :
“Japanese Knotweed, Polygonum cuspidatum, or Fallopia japonica is an aggressive semi woody perennial introduced to Canada in the 1800’s as an ornamental plant.”
“Japanese Knotweed spreads via huge underground roots (rhizomes), that can grow 2 metres deep and 15 metres horizontally away from the above ground clump of stems. These factors have to be taken into consideration when attempting to control it. In Ontario, the OIPC (Ontario Invasive Plant Council) recommend digging up plants as soon as they sprout in the spring, being careful to dig up the entire root (rhizome). Young plants can be controlled by removal, but established clumps require an ongoing effort. Start by cutting the plant down to ground level in the spring and covering the stumps in a thick, pliable, light blocking tarp. This must remain in place until the knotweed is controlled. Since this can take several years, it is not a very attractive option for the home garden. To improve the aesthetic of your garden, you may choose to cover the tarp with mulch. If you have a slight slope you can add a layer of soil, about 6 inches thick, and plant with ground covers suited to your light conditions, especially species that spread by runners (stolons) or have shallow root systems. If your tarp is on a medium slope, you may need to retain the soil with heavy stones/pavers/logs, being careful not to tear through the fabric. If your site has a steep slope, don’t add anything on top of your tarp. If you wish to grow larger plants, you can build/purchase a planter(s) and place on top of the tarp. Fill planters with soil and plant as usual. For more details see: