Weeding Tips

Hand-pulling is very effective in a densely planted area such as a vegetated stormwater system.

Remove roots. It is not enough to remove the portion of the plant that is aboveground–often weeds will sprout back from roots left buried in the soil. If hand-pulling is leaving roots behind, consider grabbing a garden hoe or trowel. Or plan to weed the area after watering or rainfall when the soil is moist.

Don’t let it go to seed. Remove a plant before it has the chance to flower and go to seed, giving new weeds the opportunity to sprout everywhere. The seeds of species like garlic mustard will continue to mature even after the plant has been pulled.

Herbicides may be needed on particularly aggressive invasive plants. This MUST be done by a certified applicator using the least amount of chemical necessary. Applying the herbicide to the freshly cut stem near ground level is safest. Do not apply herbicide when plants are in flower.

Bag it up. Many invasive plants can resprout if they have contact with soil, so drying them out on a paved surface or bagging them for disposal is important. Many plants can form roots when their stems are left in contact with soil. Japanese knotweed can root from just a fragment of stem. ALWAYS bag and remove any invasive plants you pull,

Tools to have on hand: work gloves, knee pads, full-sized and hand-held garden hoes, flat shovel, and trash bags.

Revegetate. The removal of invasive plants or weeds opens up the newly-exposed soil for invasion, so replanting is important. Be prepared to replace those weeds or invasive species with a native plant that will be well-suited to the garden that you are maintaining. Head to the Rhode Island Coastal Plant Guide and use the drop-downs to specify the site conditions of the bioretention area. This will generate a list of appropriate native plants from which to choose.

DON’T SPREAD IT!

Thwart these expert invaders by keeping field gear clean and thoroughly removing plant matter from sites:

Purple loosestrife and Japanese stiltgrass have tiny seeds that stick to shoes, tools, and especially equipment tires.

Mugwort is spread by root fragments, sometimes existing in soil brought to an area. Check soil source!

Japanese knotweed can root from as little as a fragment of the stem, so mowing is not recommended.

More About Herbicides and Pesticides

Pesticide Safety & Integrated Pest Management Training is conducted by URI to prepare for certification by RIDEM. 

Rhode Island Pesticide General Permit, applies to pesticide use patterns that result in discharge of pesticides to Waters of the State. 

Pollinator Working Group, or The Working Group to Make Findings and Recommendations with Regard to Maintaining, Protecting and Enhancing Pollinator Habitat and Health in Rhode Island, provides guidance for the use of pesticides around pollinators.