Honeysuckle, belonging to the genus Lonicera, is recognized globally for its intensely fragrant, tubular flowers and rapid growth habit. This genus includes diverse climbing vines and arching shrubs found across northern latitudes in North America and Eurasia. Many species have been cultivated for centuries, valued for their ornamental beauty and the sweet aroma they release, particularly in the evening. Understanding the specific type of honeysuckle you encounter is the first step in deciding how to interact with it, whether for appreciation, culinary use, or removal.
Identifying the Types of Honeysuckle
Distinguishing between native and non-native honeysuckle species is the most important factor for management, as non-native varieties are ecologically aggressive. A simple physical test can often provide immediate clarity: native honeysuckles, such as the North American trumpet honeysuckle (Lonicera sempervirens), possess stems with a solid white pith. In contrast, the most common invasive shrub honeysuckles, like Tartarian (Lonicera tatarica) and Amur (Lonicera maackii), have a hollow, brown pith. Invasive shrub varieties grow as dense, upright bushes, often reaching heights of 6 to 20 feet, and are among the first plants to develop leaves in the spring and the last to drop them in the fall.
The invasive Japanese honeysuckle (Lonicera japonica) grows as a woody vine that can climb up to 30 feet, twining tightly around supports. This aggressive growth habit can cause girdling, which chokes the host plant. The leaves of most invasive honeysuckles are oval-shaped with smooth edges, while native species often have leaves with serrated margins. Invasive shrub honeysuckles typically produce flowers that start white or pale yellow and fade to a deeper yellow, followed by red or orange berries that are abundant and dispersed widely by birds.
The ecological impact of these invasive species is significant because their early leaf-out allows them to shade out native understory plants, monopolizing light and soil nutrients. This forms dense thickets that prevent the regeneration of native tree seedlings and reduce the biodiversity of the ecosystem. Furthermore, the berries from invasive species often lack the high fat and nutrient content that native bird species require, providing a less beneficial food source.
Culinary and Aromatic Applications
The flowers of certain honeysuckle varieties are used in culinary applications, prized for their delicate, sweet nectar and fragrance. The most common use involves harvesting fully bloomed flowers to create infused simple syrups, which flavor beverages or are drizzled over desserts. Flowers can also be steeped to make a fragrant tea or added to sugar to create floral-scented jellies and jams.
Caution is required when considering consumption, as the flowers are the only part of the plant widely regarded as safe to eat. The berries of nearly all honeysuckle species common in North America, including invasive varieties, are considered toxic to humans and can cause severe digestive distress, including vomiting and diarrhea. Never consume the leaves, stems, or berries unless you are certain of the species, as even small quantities of toxic berries can cause illness.
Beyond edible uses, the intense, sweet scent of honeysuckle is a favorite in the world of perfumery and aromatherapy. These compounds are often extracted to produce essential oils, although the process can be complex. In a garden setting, planting a fragrant honeysuckle near a patio or window allows the natural scent to drift into living spaces, providing a natural aromatic experience without requiring extraction.
Ecological Management and Removal
For homeowners dealing with invasive honeysuckle, a multi-pronged approach combining physical and chemical methods is most effective for permanent removal. Small seedlings and young plants can be removed manually, especially when the soil is moist, by grasping the plant at the base and pulling to ensure the entire root system is extracted. For larger, established shrubs or vines, a more robust technique is necessary to prevent persistent re-sprouting.
The most effective method for established plants is the cut-stump treatment, which is best performed in the late fall or early winter when the plant is actively drawing resources toward its roots. This involves cutting the woody stem as close to the ground as possible, then immediately applying a concentrated systemic herbicide, such as glyphosate or triclopyr, to the fresh cut surface. The herbicide must be applied only to the vascular cambium to ensure the chemical is transported throughout the root system.
If chemical application is avoided, the technique of solarization can be used by cutting the plant low to the ground and then covering the stump with a thick, opaque material like black plastic sheeting. By blocking all sunlight, this method starves the root system and prevents photosynthesis, though it may take several months to kill the plant completely. Once the invasive honeysuckle is removed, planting native, non-invasive alternatives, such as trumpet honeysuckle, is important to stabilize the soil and prevent new invasive seeds from establishing.