The following plants are considered invasive in PEI. They spread quickly, outcompete and suppress native species, and can drastically reduce the biodiversity of an area. Invasive species can also create negative implications for the economy, human health and recreation. The PEI Invasive Species Council is working with a number of organizations, government departments and individuals to stop the spread and prevent introductions of invasive alien species. Visit www.peiinvasives.ca for more information about invasive species in PEI
YOU CAN HELP! Learn more about invasive species in PEI, including how to identify species of concern Choose native species to plant in your garden Inspect and clean clothing, gear, animals, and vehicles before visiting a new natural area Eradicate populations of invasive species on your property and dispose of them properly Report a sighting to Island Nature Trust by phone: (902) 892-7513 or via the website For more information on invasive species on PEI visit: www.peiinvasives.ca This project was undertaken with the financial support of the Government of Canada.
Himalayan Balsam
Himalayan Balsam Impatiens glandulifera ŸGrows up to 2m tall ŸRed, bamboo-like, stem ŸDeep pink-white flower with sac structure ŸBlooms June - October ŸSeed pods are teardrop-shaped and the slightest pressure will cause mature pods to explode and release seeds ŸOpposite leaves are long, slender and sharply-toothed ŸForms large, dense stands It prefers moist soils and can be found along trails and in ditches in PEI.
Common Buckthorn
Common Buckthorn Rhamnus cathartica ŸHas a look-a-like relative, Glossy Buckthorn ŸHas slightly-toothed leaf edges ŸHas a spike at the end of its branches ŸGreen-yellow flowers grow in close bundles and bloom mid-spring to early summer ŸFlowers form green berries, which ripen to blue-black in late Summer. ŸBerries remain into the winter It grows best in full sun but is very tolerant of shade and can flourish under openings in the forest canopy.
Yellow Flag Iris
Yellow Flag Iris Iris pseudacorus ŸMore robust than native iris species ŸLeaves are sword-shaped, 0.5-1.5m long, 1-3cm wide and have a raised midrib ŸLarge yellow flower with 3 petals facing up and 3 petals hanging down ŸBrown-purple stripes on petals ŸBlooms June - August ŸSeed pods resemble small, green bananas ŸForms large clumps with extensive root systems It prefers full sun or partial shade. It is often found in grasslands, disturbed areas, urban areas, gardens, and freshwater wetlands.
Giant Hogweed
Giant Hogweed Heracleum mantegazzianum ŸLocal look-a-likes: Queen Ann s Lace and the native Cow Parsnip ŸCan grow to 5 m tall ŸInflorescence can be 1.5m in diameter ŸMany white flowers bloom June-August ŸHollow stem covered with purple streaks and spots and coarse hairs ŸLeaves have 3 deeply-lobed, jagged edged, leaflets ŸSeeds are oval-shaped with 4 dark lines ŸCAUTION: sap can cause severe photodermatitis if it comes into contact with skin and is exposed to UV rays It prefers moist soil and is known to grow in freshwater wetlands, grasslands, disturbed areas, urban areas, and gardens.
Japanese Knotweed
Japanese Knotweed Fallopia japonica ŸSemi-woody, bamboo-like stems can be red-purple and grow 1-2m tall ŸFlowers are white-yellow and grow on small, branching, stems ŸBlooms from July-September ŸLeaves are oval shaped with pointed tip, straight at the base, and are arranged alternately ŸSpreads by extensive root system and forms dense stands It prefers full sun and moist soil but will tolerate part shade and drought. It grows well in wetlands, riparian zones, lawns, gardens and ditches.
Purple Loosestrife
Purple Loosestrife Lythrum salicaria ŸWetland perennial plan, grows 1-2m tall ŸSquare stem; leaves can be opposite, alternate or whorled ŸFlowers are small and purple, and many individual flowers grow on a single spike ŸBlooms from late June-September ŸCan have as many as 50 shoots coming off a single root ŸHybrids of loosestrife can produce viable seed and escape the garden ŸOften mistaken for fireweed It can be found surrounding a number of ponds and in many gardens on PEI.
Scotch Broom
Scotch Broom Cytisus scoparius ŸEvergreen shrub, 1-3m tall ŸProduces many yellow, pea-like flowers ŸBlooms from May-June ŸLeaves near base have 3 leaflets ŸAll other leaves are simple ŸHas a bright green, woody, angled stem with grooves ŸSeed pods look like hairy, flat pea pods and turn from green to dark brown/black It can grow well in poor soil conditions, but does not tolerate much shade. It often inhabits disturbed areas, open fields, ditches, and gardens.
Garlic Mustard
Garlic Mustard Alliaria petiolata ŸFirst year plants form leafy rosettes close to the ground ŸSecond year plants can reach 1m and have a flowering stalk, with pointed leaves ŸSmall white flowers with 4 petals ŸFlowers grow in small clusters at the top of leafy stems ŸLeaves are triangular-heart-shaped and have serrated edges ŸPlants emit a very strong garlic smell It is very tolerant of shade and grows well under forest cover. It is not yet widespread on PEI.
Periwinkle
Periwinkle Vinca minor ŸGroundcover perennial, growing to 6 inches tall Ÿ Has glossy, evergreen, leaves with a faint white mid-vein ŸProduces long trailing stems that grow along ground ŸSingle flowers bloom along the stem ŸFlowers are pale blue-purple, 3 cm wide, and have 5 petals ŸBlooms from May-June It grows well in shade and a wide range of soil types. It can often be found growing in forests, urban areas and gardens.
Wild Cucumber
Wild Cucumber Echinocystis lobata ŸVine-like growth Ÿ5 lobed leaves are heart-shaped and paired with a tendril ŸFlowers are small, white, and 6-petaled ŸMale flowers grow in clusters along long branching stalks; female flowers grow in solitude at base of stem ŸBlooms from July to August ŸProduces prickly, oval-shaped fruit which release the plant's seed when it has reached maturity It is a member of the gourd family. It requires moist soil and full sun.
Glossy Buckthorn
Glossy Buckthorn Frangula alnus ŸClosely resembles Common Buckthorn Ÿgrows to be 4-5m tall ŸLeaves are simple, rounded, glossy, and deeply veined with smooth edges ŸGreenish-white flowers grow in clusters. Blooms in May ŸFlowers yield berries that ripen to blue-black in late summer-september ŸUnlike Common Buckthorn, it has no thorn at the end of each branch It tolerates a wide variety of growing conditions - from dry to wet soils and full sun to part shade.
Eurasian Water Milfoil
Eurasian Watermilfoil Myriophyllum spicatum ŸMost of this aquatic perennial remains submerged ŸLong, slender stems grow 1-4m long ŸLeaves grow along stem in whorls of 3-4 ŸLeaves are comprised of 12-16 pairs of fine leaflets ŸSmall, yellow flowers are produced at the top of a stalk that grows 5-10cm above the water surface ŸIt forms large, floating mats that block sunlight from getting to plants below It does best in warm, nitrogen-rich, waters that are highly disturbed.
Multiflora Rose
Multiflora Rose Rosa multiflora ŸMedium-sized shrub, can grow to 5m tall ŸBranches form wide arches and spread quickly Ÿ5-petaled white flowers grow in clusters ŸFlowers bloom from May- June ŸSmall bright red hips ŸCompound leaves with 5-11 leaflets on each leaf ŸLeaf edges are sharply serrated ŸThorns present on stems It tolerates a wide range of growing conditions and is often found in fields, along roadsides and under gaps in forest
Goutweed
Goutweed Aegopodium podagraria ŸPopular in gardens as a groundcover ŸProduces clusters of small, 5-petaled, white flowers ŸFlowers bloom from May- June ŸFlowers form on stalks that can grow to 1m ŸLeaves divide into 3 groups of 3 leaflets, and leaf stalks attach to an underground stem ŸSpreads by extensive underground root system It tolerates full sun to part shade and a wide range of soil conditions. Most populations on PEI arise as a result of garden dumping.