With the onset of cooler temperatures, it’s time to prepare the garden for winter. It’s important to plan ahead and dispose of invasive plants and seeds hidden in leftover hanging baskets, planters, and yard debris. By using proper removal methods, home gardeners can anticipate a healthy, invasive-free garden in the spring while protecting nearby ecosystems.
1. Trash / Landfill
Use heavy trash bags to gather all invasive plants and plant parts, making sure that no parts of the plants poke through, and cinch the bag securely. This waste should include contents of annual planters and hanging baskets, since many flower mixes sold in stores contain invasive seeds. Be sure to use the right type of bag required for yard waste (curb-side removal) in your municipality.
If you prefer to take a load of yard waste to the local landfill, bag all vegetation that may contain invasive plants, and cover with a tarp on-route. Inform the landfill operator that you have invasive plants and not simple yard waste; there may be a specific location for this harmful debris, which is typically buried or incinerated. Some regional districts waive the tipping fees for disposal of invasive plants.
Incineration of invasive plants is best left to the landfill; invasive plants with airborne seeds may disperse with the hot air created by the fire, and temperatures needed to destroy seeds varies between species. There may also be burning restrictions to consider.
That said, where safe and legal (get a permit if required), a significant volume of invasive plant debris can be destroyed with a burn pile. Be sure to dispose of the debris remaining on the site after a burn, as this may still contain viable seeds. Douse the embers thoroughly after the pile has burned down completely. An open area of dirt or sand is best, keeping away from buildings and vegetation, or anything flammable. Note that not all invasive plants should be burned; never burn poison ivy or poison oak, which release volatile oils that are harmful if inhaled.
3. Compost - Not recommended
Although composting tends to be the first method gardeners choose to dispose garden waste, it is not recommended for invasive plants. In some commercial facilities with specific invasive plants, they may be able to achieve the right temperature for the required duration to ensure that all seeds are not viable. This is hard to achieve in the average backyard compost in BC, even when the pile is covered.
Another way to dispose of some unwanted plant species, is to dig a deep pit (at least three feet deep) and bury them in an area that is unlikely to be disturbed. Cover and weigh down the spot with a board, stones, or old tires. Over time the debris will rot and break down, losing volume. At which point more plant waste can be added.
Ways to Prevent Invasive Plant Spread:
- Scout property regularly for invasive plants, and remove them before they become widespread.
- After proper disposal, replace them with a more desirable species; disturbed soil creates prime conditions for the invader to return.
- Take care not to ‘recycle’ garden debris into a park or natural area. This introduces plants that aggressively smother the vegetation that wildlife depend upon for survival, and otherwise harms the aesthetics of shared parks and green spaces.
- Rinse grass cuttings from the lawnmower before taking it to another location, such as a summer cottage, to prevent spreading seeds.
When removing invasive plants, keep in mind how easily they can spread to new areas through their cuttings and seeds, and plan their disposal carefully. Become aware of local program and options for disposal by contacting your regional district.
Sources: City of Coquitlam; Capital Regional District; City of Nanaimo; and Cariboo Regional District; Okanagan and Similkameen Invasive Species Society (OASISS); Invasive Species Council of Metro Vancouver (ISCMV).