Hedera helix

Origin: This ivy, native to Europe, was introduced to North America during colonial times as an ornamental. It is still widely planted for this purpose.

Description: English ivy is an evergreen, woody vine that can climb, clinging with aerial roots, or can form dense ground cover. It can grow to around 100 feet long. Its thick, waxy leaves are alternate and most typically have 3-5 pointed lobes, but their shape varies. Mature plants of about 10 years old often have unlobed leaves which are wide at the base and taper to a point. Leaves are dark green above, with whitish veins radiating from the leaf stem, and are pale green beneath. Leaf stems are often reddish-tinged. Hairy-stemmed clusters of tiny, greenish-yellow, 5-petaled flowers are present on mature plants from June until October. Fruits are clustered berries 0.2-0.3 inch in diameter. These are pale green in late summer, ripening to dark blue or purplish in late winter or spring.

Distribution: English ivy invades woodlands, fields, and other upland areas. It avoids wet areas but can tolerate a fairly wide range of soil and moisture conditions and particularly thrives in moist, open forests. Young plants are shade tolerant, and plants adapt to higher light levels as they mature.

Problem: English ivy can replace native understory species when growing along the ground. When it climbs trees, it often completely surrounds their branches, slowly killing them. It can also host bacterial leaf scorch that infects oaks, elms, and maples.

Control: Hand-pulling of seedlings or small plants may be effective, but care should be taken not to disturb the soil more than necessary. Glyphosate (3%) or triclopyr (3%) may be sprayed onto leaves. This can be done anytime during the growing season, but may be best in the early fall when native plants are dormant, but the target plant is still green and physiologically active. Winter treatment may be possible if green leaves are still present and the high temperature exceeds 50? F. When applying herbicide to a plant with waxy leaves, consider adding 0.5% non-ionic surfactant to the herbicide mix if recommended on the herbicide label.

USE PESTICIDES WISELY: Always read the entire pesticide label carefully, follow all mixing and application instructions and wear all recommended personal protective gear and clothing. Contact your state department of agriculture for any additional pesticide use requirements, restrictions or recommendations.