Yellow flag iris is a well-established invasive species in Richmond, native to Europe, western Asia and North Africa. Known for its bright yellow flowers, it invades wetlands, ditches and shorelines, forming thick stands that displace native species. It spreads by seed and creeping rhizomes, which can move easily through water, complicating control efforts and impacting aquatic habitats.

Himalayan blackberry is a well-established invasive species in Richmond, native to Armenia and Northern Iran. While valued for its fruit, it forms dense, thorny thickets that crowd out native plants and limit access. Each square metre can produce 7,000–13,000 seeds that may germinate quickly or remain dormant in the soil. It also spreads through root and stem fragments, making it difficult to control and a concern for parks, utility corridors and transportation routes.

Yellow archangel is a spreading invasive species in Richmond, native to Europe. Often planted as an ornamental groundcover, it forms dense mats that outcompete native vegetation, especially in shaded areas. It spreads through creeping stems that root at the nodes, allowing it to expand quickly and making control difficult in forests, parks and natural areas.

Periwinkle is a well-established invasive species in Richmond, native to Europe. Valued for its evergreen foliage and purple flowers, it spreads rapidly to form thick groundcover that suppresses native plants. It reproduces through trailing stems that root as they grow, enabling it to cover large areas. It persists in forests, parks and urban green spaces.

Morning glory is an aggressive invasive species in Richmond, native to Europe and Asia. Recognized for its white to pale pink funnel-shaped flowers, it grows as a climbing or trailing vine that twines around plants and structures, smothering native vegetation. It spreads by both seed and an extensive root system, making it difficult to control and a persistent issue in gardens, roadsides and disturbed areas.

Knotweed species are one of the most aggressive invasive plants the City manages. Knotweed has the ability to damage crucial infrastructure, including the Richmond dike system. It is capable of growing through cracks in cement, asphalt, house foundations and walls. Knotweed species form dense thickets and often outcompete native plant species and decrease local biodiversity.

The City’s Knotweed Treatment Program manages over 500 knotweed sites with selective herbicide application. It is estimated the program has reduced knotweed infestations by 80%.

Giant hogweed is a hazardous plant that poses a serious threat to human health and the local ecology. Contact with sap from the stem, hairs and leaves can cause severe burns and blisters on the skin, while contact with the eyes can cause temporary or permanent vision problems.

The City actively monitors public lands for giant hogweed and frequently asks for the community’s help to rapidly identify and eliminate new infestations of it in Richmond. If you observe a plant that looks like giant hogweed please contact the City for identification.

Do not attempt to remove giant hogweed yourself. Please contact the City for assistance.

Parrot’s feather is an aquatic invasive plant that was likely introduced into Richmond around 2007 through an aquarium or pond plant. Since then, it has spread to several City drainage canals and sloughs. This fast growing plant forms dense mats that outcompete native species, decreases local biodiversity and can cause water to become stagnant, altering the health of aquatic ecosystems

To address this issue, the City has been maintaining drainage canals and sloughs to ensure proper flow. Through ongoing management efforts and trial projects, Richmond has helped develop best management practices for controlling parrot’s feather in Metro Vancouver.

Brazilian elodea is an aggressive aquatic plant sold in the aquarium-trade. It forms dense mats up to four metres deep in still and flowing water sources posing a serious threat to local ecosystems. Recognized provincially as an Early Detection Rapid Response species, Brazilian elodea must be managed with the goal of eradication. There are only three known sites in British Columbia and its presence is a significant concern due to the plant’s ability to regenerate quickly. The plant was likely introduced into the City’s drainage system from the improper disposal of residential aquarium contents.

Since 2014, the City has partnered with the Province of BC to manage a large infestation near the West Dike. With support from the Province, the City implemented an integrated pest management approach to manage Brazilian elodea in 2017. The project is now in the monitoring stage and no new detections have been recorded since 2021.

Fire ants were first recorded in BC in 2010 and have since been discovered in isolated locations throughout the Lower Mainland. These aggressive ants can deliver a painful, burning sting. Fire ants thrive in moist environments such as tall grass, well irrigated lawns, raised garden beds and in areas with lawn clutter. They also like heat, which can come from paving stones, ornamental stones and landscaping wood.

It is important to note many native species of ants, including red ones, are commonly found in our region. European fire ants can be difficult to identify. Please contact the City for support with identification procedures. If fire ants are confirmed, a coordinated approach with your neighbours is essential to manage infestations.

Eurasian watermilfoil is an aquatic invasive plant found submerged in still or slow moving freshwater streams, canals and lakes. It has tiny reddish flowers that grow on spikes that rise five to 20 centimetres above the water. It reproduces by seed, root and plant fragments, which can be carried in water, on vehicles and on equipment.

Eurasian watermilfoil can affect the City’s infrastructure by impeding flood control, storm drain systems and irrigation works. It restricts water movement and traps sediments, leading to increased municipal maintenance costs. Dense patches of Eurasian watermilfoil outcompetes native aquatic vegetation, resulting in reduced habitat quality for aquatic species.

Common reed is a perennial grass that can grow between two to five metres tall with feather-like flower clusters ranging from 15 to 35 centimetres long. Recognized provincially as an Early Detection Rapid Response species, common reed must be managed with the goal of eradication. It is found in freshwater, brackish tidal wetlands, coastal shorelines, wetlands, sloughs, canals, ponds, ditches and watercourses. It can alter the hydrology of water flow, which can impact the City’s open drainage network and cause safety hazards by obstructing driver’s sight lines. It also is a significant threat to the agricultural croplands, such as blueberry and cranberry fields.

Richmond was the first confirmed common reed site in BC and identified by City staff, who promptly sent samples to verify the species. With the Early Detection Rapid Response partnership with the province, the infestation was fully contained and controlled and has since been eradicated from the known site.

European chafer beetle is an introduced insect to BC that has become a serious lawn pest in Metro Vancouver. The chafer larvae (grubs) damage lawns and boulevards by feeding on the roots of turf grass, resulting in the appearance of brown (dead) patches in affected lawns. The major damage to lawns occurs when crows, skunks and other animals dig up the lawn in search of these grubs in early spring and fall. Adult beetles do not cause any significant damage. They are short-lived and do not bite or sting.

In partnership with West Coast Seeds, four alternative lawns are displayed at Terra Nova Rural Park for residents to determine options to suit their space. These seed blends resist chafer beetle infestations, are drought tolerant and support pollinator species.

Japanese beetle is a regulated, invasive pest that poses an exceptional threat to a wide variety of urban plants and agricultural crops. Adult beetles eat the flowers, foliage and fruit of more than 300 plant species. Their larvae also feed on the roots of lawns and other plants. In 2022, one individual beetle was captured through routine trapping near the City Centre and treatment was administered within the area of detection in 2023 and 2024. The City is working collaboratively with the cities of Vancouver, Port Coquitlam and Burnaby, senior levels of government and industry to prevent further spread and eradicate Japanese beetle from the Metro Vancouver region.

Scotch broom is a shrub that can grow one to three metres in height with bright yellow pea-like flowers. It invades open and disturbed areas and is found along the dike and roadsides. A mature plant can live up to 25 years and produce seeds that are viable in the soil for 30 years. It can increase wildfire risks, obstruct sightlines along roads and crowd out native plants.

In 2025, City operations staff mechanically removed Scotch broom along the dikes using machinery and specialized tools to minimize disturbance to the existing seed bank. Annual monitoring will be essential to ensure regrowth is minimal.