Japanese honeysuckle is an attractive vine, but it can also be an invasive plant that poses problems in the yard. Before deciding whether or not to plant Japanese honeysuckle, learn which regions this plant is invasive in and why gardeners living elsewhere might want to include it in their landscaping.
Taxonomy and Botany of Japanese Honeysuckle
According to plant taxonomy, Japanese honeysuckle is Lonicera japonica. Technically, there is a cultivar named "Hall's" (Halliana) that is botanically distinct from the species plant, but the two are similar enough to be treated as the same plant.
Japanese honeysuckle plants are flowering vines that are deciduous in the northern climates but semi-evergreen or evergreen farther south. These plants are climbers that twine around vertical objects. Some growers choose to train them up garden arbors.
Characteristics of the Vine
Leaves of Japanese honeysuckle grow in a so-called "opposite" pattern along the stems, one across from the other. Although some gardeners may find its leaves moderately attractive, there is no question as to what Japanese honeysuckle vine is grown for its blooms. These vines bear white flowers, sometimes with pink accents. The older white flowers tend to fade to a yellowish color, even while new ones continue to appear. This means that, at any given time, it is possible for Hall's to have flowers on it in all three colors of white, pink, and yellow.
The fragrant flowers are succeeded by blackberries, which are toxic if eaten. This is why Japanese honeysuckle is considered a poisonous plant and should not be planted where children may have access to it. The vine blooms in a zone-5 landscape in June.
Homeowners may also be tempted to grow Japanese honeysuckle due to its shade-tolerance. Finding vines that grow well in shade can be a challenge, particularly flowering types. The flowers also attract hummingbirds and butterflies.
Invasiveness of Japanese Honeysuckle
Japanese honeysuckle is indigenous not only to Japan but also to Korea and China. Due to its invasive nature, it is also found widely in eastern North America, having escaped from home gardens into the wild, where it has become naturalized. It is likely to be invasive in other regions outside of its homeland with similar climates. Japanese honeysuckle vine can be used as a specimen plant in regions where it is not invasive.
There are many plants called "honeysuckles," including some that are not vines. For example, there is an invasive honeysuckle bush that is widespread in the Northeastern U.S., named "Morrow's honeysuckle." Other vine-form types also exist.
Japanese honeysuckle can spread either underground (via rhizomes) or aboveground (by wild birds eating the berries and depositing the seeds elsewhere). It is listed as an invasive plant as far up the East Coast of the United States as the southern parts of New England. It is a true menace in parts of the country where the foliage is evergreen and thereby more vigorous. In the South, Japanese honeysuckle grows so aggressively that its weight poses a danger to trees when it climbs into their canopies. The plant can also harm shrubs and small trees by girdling them.
In northern New England and other similar climates, Hall's Japanese honeysuckle is unlikely to spread aggressively. Check with your local county extension to inquire about Japanese honeysuckle's invasive status in your area.
Growers in North America seeking a noninvasive alternative to Japanese honeysuckle could plant any of the various types of trumpet honeysuckle (Lonicera sempervirens). These North American natives are generally cold-hardy to around planting zone 4. The drawback is that their flowers are not fragrant (or at least not as fragrant as those on their invasive counterpart). Grow them in full sun and in average soil. Depending on type and conditions, these vines can become as tall as 15 feet high, with a maximum spread of about 5 feet. Prune the plants after flowering, if necessary.
Examples of some of the colors and cultivars available are:
- Red: Alabama Crimson
- Yellow: John Clayton
- Orange: Magnifica
Do not confuse trumpet honeysuckle plants with trumpet vines, which are also hummingbird magnets (but highly problematic, being very aggressive spreaders).
Other types of Lonicera vines include:
- Lonicera caprifolium
- Lonicera x heckrottii
- Lonicera x tellmanniana
- Lonicera periclymenum