Native to Europe, eastern Asia, and Japan, bush honeysuckles were introduced in the 1800's as ornamentals. They were also planted for wildlife food and cover. The various species quickly naturalized and can now be found from New England south to North Carolina and west to Iowa. The two species commonly found in Pennsylvania are Tartarian honeysuckle (Lonicera tatarica) and Morrow's honeysuckle (Lonicera morrowii).
Bush honeysuckles reach heights up to sixteen feet tall. The simple, oval to oblong leaves have opposite arrangement. Leaves appear in early spring and remain on the bush until November. The shaggy barked stems and branches of mature honeysuckles are hollow. Bush honeysuckles flower between May and June producing tubular, fragrant flowers. Tartarian honeysuckle produces pink flowers, while Morrow's are yellowish white. Both honeysuckle species produce fruit that matures between July and August. Tartarian honeysuckle berries are reddish, while the Morrow's berries are orange. The multi-seeded berries are born in pairs.
Non-native bush honeysuckles are easily distinguished from native species. The native stout, erect shrubs grow in dry or rocky sites, while the non-native honeysuckles prefer moister soils. Another identifying characteristic of the native honeysuckles are the yellow flowers. Invasive honeysuckles leaf out one to two weeks before the native honeysuckles and hold their leaves later into the fall.
Honeysuckles grow in a wide range of habitats. They can be found in abandoned fields, along roadsides, near marshes, and in recently disturbed woodlots. They tolerate varying moisture conditions. Honeysuckles will grow in moderate shade but thrive in full sun. Birds feed on honeysuckle berries, spreading the seeds. Seeds in the soil can remain viable for several years waiting for the correct conditions to sprout.
Honeysuckles spread quickly and are very invasive. A light infestation of bush honeysuckle can be cleared by hand because of it shallow root system. When removing the honeysuckle by hand, take care to remove all of the roots, because new sprouts will grow from the root system.
There are several methods for controlling severe infestations of bush honeysuckle. Cutting them in early spring and late fall for several years will eventually kill the honeysuckle by reducing the plant's reserve nutrients. Do not cut the bushes in the winter because this will cause the plant to resprout vigorously. Applying a glyphosate herbicide to the leaves or a freshly cut stump late in the growing season will also help control bush honeysuckles. Glyphosate kills non-target species so care must be taken when spraying the foliage. Conducting prescribed burns during the growing season for several years also reduces the amount of bush honeysuckle in an area. Replanting disturbed woods with native species is a good way to discourage an infestation of nonnative bush honeysuckle.
Prepared by Anne T. Lenox, Forest Resources Extension staff and undergraduate in Forest Science
The first two photographs are used with the permission of (c)John Randall/The Nature Conservancy. The third photograph is used with the permission of Kenneth R. Robertson.