Old Man’s Beard
Clematis vitalba AKA Old Man’s Beard
Old man’s beard, a rapidly growing vine was introduced to New Zealand sometime before 1922 as an ornamental garden plant. Today, the plant is classified as an Unwanted Organism by the Department of Conservation and the Ministry of Primary Industries. It can climb into the canopy, smothering and eventually collapsing even tall trees, transforming forests into impenetrable, low-growing thickets. A single plant can grow up to 20 metres long, covering an area of 180m². That’s equal to twelve parking spaces or one-third of a basketball court. Usually, the plants grow in groups, too, hampering the establishment of native seedlings, and halting natural succession processes in our native bush.
What does it look like?
The plant is a deciduous climbing vine that can reach heights of up to 20 meters. Its woody stems exhibit six prominent ribs and feature pale bark that easily rubs off. Leaves are positioned in opposite pairs along the stems and are composed of five leaflets, akin to the fingers of a hand. These leaflets are thinly covered in sparse hairs and bear edges that are either bluntly toothed or smooth. Fragrant, creamy-white flowers grace the plant from December through May, succeeded by dense, fluffy clusters of seeds that endure through the winter months.
Notably, the flower buds begin as greenish-white before maturing into pale yellow blooms. This vine distinguishes itself from native species by having five leaflets per leaf, whereas native species typically have three. Additionally, it sheds its leaves annually, exhibiting deciduous behaviour.
Are there any similar species?
It’s important to note that it’s easy to confuse native Clematis spp., especially C. paniculata with exotic species. Distinctions include the number of leaflets (five in old man’s beard, three in natives), the absence of lines or grooves on stems, and flowering from December to May. All native clematis species are evergreen, featuring three leaflets (except the leafless C. afoliata), unfurrowed stems, and flowering from August to December. In contrast, exotic species like Old Man’s Beard are deciduous, except the occasionally weedy, pink-flowered C. montana, which flowers from October to December. Old Man’s Beard vine undergoes seasonal changes, with young vines having purple longitudinal ribs, mature vines featuring stringy, pale brown bark, and old vines becoming woody and stringy, often in grey colour.
Where does it grow?
Clematis vitalba is a light-demanding species. It thrives in a variety of habitats characterized by light availability. It flourishes in diverse environments such as low forests, scrublands, shrublands, riparian margins, and well-lit forest edges. Its versatility extends to wide tracks, waterways, and clearings where it finds suitable conditions for growth.
It is particularly fond of coastal and lowland regions. These areas provide the optimal combination of moderate to high soil fertility and good drainage, allowing the plant to establish and proliferate successfully. Its ability to adapt to different soil types and moisture levels makes it a resilient inhabitant of various landscapes, where it can quickly colonize and spread if left unchecked.
Where did Old Man’s Beard Come from?
Old man’s beard was introduced to New Zealand as an ornamental garden plant sometime before 1922. It originates from Europe & South West Asia. Here it has no natural enemies and grows rapidly forming a dense, heavy mass dominating lowerland forest margin canopies. First found growing wild in the mid-1930s in the southern North Island and northern South Island. Considered naturalised by 1940, it continued to spread rapidly throughout the country. Councils from Northland to Southland have active management programmes for controlling its spread and damage to our native species.
Why is it a Problem?
The problem with Old Man’s Beard lies in its invasive nature and rapid growth. It attaches to other plants using leaf tendrils, spreading like a curtain and posing a threat to native trees and shrubs. This inhibits the growth of native seedlings. The vine reproduces abundantly through seeds that remain viable for many years and by rooting stem fragments, allowing it to quickly take over various habitats such as gardens, road reserves, and forests. Despite efforts to control it, Old Man’s Beard persists and continues to spread, impacting biodiversity and recreational areas.
Old Man’s Beard can smother and collapse even tall trees, reducing forests to impenetrable masses of the vine. It spreads rapidly by layering over the canopy of established forests. The plant produces vast amounts of long-lived seeds and reproduces vegetatively, making it difficult to eradicate. It thrives in various conditions and is particularly troublesome in areas with fertile soil and ample light. Additionally, it is frost-tolerant, resilient to damage, and can withstand different environmental conditions.
Overall, Old Man’s Beard poses a significant threat to ecosystems, biodiversity, and recreational spaces due to its aggressive growth and ability to outcompete native vegetation.
Listed in the 2020 National Pest Plant Accord.
Old Man’s Beard is such a problem it is included in the 2020 National Pest Plant Accord (NPPA), which is an agreement aimed at preventing the sale and distribution of certain pest plants in New Zealand. The NPPA targets plants that pose a significant risk to the country’s economy and environment, especially when spread through horticultural trade. The Department of Conservation and the Ministry of Primary Industries classify it as an Unwanted Organism, indicating its potential to harm natural resources and human health.
In Canterbury, efforts to manage Old Man’s Beard are part of a sustained control program due to its foothold in the region. Eradication or containment has proven difficult, with the main concern being its spread to neighbouring properties. The control program aims to at least maintain current pest populations until 2038. Larger infestations are addressed through site-led programs, with potential funding assistance available from Environment Canterbury.
For more information and resources on the NPPA, including plant details and images, visit the MPI website.
How does Old Man’s Beard spread?
Old Man’s Beard employs various mechanisms for spreading, posing a significant challenge to containment efforts. Seeds, lightweight and buoyant, are dispersed through gravity, wind, and water. Human activities inadvertently contribute to dispersal, often through contaminated footwear. Birds, unknowingly aiding in propagation, incorporate the fluffy seed heads into their nests, further spreading the plant’s seeds.
This resilient perennial species has two ways to make more plants. In spring, its seeds grow when there’s enough sunlight. It can also make new plants from pieces of its stems. If its vines touch the ground, they can grow roots, making it spread more easily.
Old Man’s Beard is a prolific seed producer, with an estimated 17,650 viable seeds generated for every 0.5 m² of plant in the canopy. Despite the initial abundance of seeds, their viability diminishes rapidly over time, although some seeds may persist in the soil for up to five years. Dumped vegetation can contain seeds and stem fragments, contributing to the plant’s spread across various landscapes, including forests, roadsides, hedgerows, vacant land, and willow swamps. So put destroyed plant material in the Red bin, not the Green bin- landfill, not compost.
How Can we control it?
The Canterbury Regional Management Plan 2018 – 2038 identifies Old Man’s Beard as a pest managed under the sustained control programme and site-led programmes. Pests in the sustained control programme vary greatly in their distribution across the region. The sustained control programme intends to reduce the impact and spread of a pest onto neighbouring properties. Exclude, eradicate, contain, reduce or control a pest within a specific place to the extent that doing so protects the values of that place.
To achieve the best results, conduct control measures between November and April when Old Man’s Beard is actively growing. When dealing with a single plant, follow the vine back to its roots. These roots can then be dug out entirely, or the vine can be cut close to the ground and treated with a herbicide gel or a glyphosate-based product.
It’s important not to allow vines to trail along the ground, as they can take root and establish new plants. However, leaving hanging stems in trees to wither and die naturally is an effective control measure. When identifying a single root is impractical, an overall foliage spray is the most effective option for control.
Biological Control
Biological control agents may be suitable to control the weed, especially if it is common but this is unlikely to eradicate the species. Contact your regional council for more information about whether biological control is an option for you. Old man’s beard leaf miner and beard mite are biological controls that can minimise the proliferation of the plant. Biological controls have not been historically successful for various reasons. While they may be suitable to control the weed, it is unlikely to eradicate the species and other techniques below will be needed. Environment Canterbury’s listing on the vine contains links to the histories of biological controls in New Zealand.
Physical Control
To effectively control Old Man’s Beard, it’s recommended to slash thick stems throughout the year, cutting them at both 1 meter above ground level and at ground level. This helps prevent resprouting from stumps and aerial roots attaching from hanging stems. After cutting, it’s important to immediately paint all cut stumps with a suitable herbicide, such as glyphosate, metsulfuron-methyl, Tordon Brushkiller, triclopyr, Banvine, or picloram gel, following the label’s directions.
Once the stems are cut, leave them to wither and die in the air, and the cutaway segments can be disposed of at a refuse transfer station or by burning. For small infestations, manually remove roots and pull out seedlings. Any plant parts that require disposal should not be composted or placed in green waste. Instead, vines, roots, and seeds should be disposed of in landfills or burned to prevent further spread.
Chemical Control Methods
After slashing thick stems, treat by painting freshly cut stumps with an appropriate herbicide e.g., glyphosate. Large infestations can be effectively eliminated with a glyphosate or clopyralid spray in spring-autumn. Stumps resprout very quickly and cut stems root at nodes. Replant bared areas promptly to minimise seedling regrowth. Check for seedlings at least 6-monthly. It’s crucial to adhere to the instructions provided by the chemical manufacturer when using these products to ensure safe and effective application.
Site Management
Effective control of Old Man’s Beard typically is not a one-off task. Regular monitoring of infested sites is essential to identify any regrowth or new seedlings that may emerge. Vines that have been previously treated may require re-treatment, while new seedlings should be promptly removed to prevent further spread.
Follow up on treated areas at least three times a year to ensure that any regrowth is promptly addressed. Encouraging natural regeneration of native plants or replanting treated areas after two to three treatments can help establish dense ground cover, reducing the likelihood of reinvasion.
Contractors can play a valuable role in implementing and maintaining control measures. Part of the maintenance program involves ongoing follow-up to identify seedlings and conduct manual control of new growth. Regular monitoring, timely treatment, and proactive management are key components of a successful control strategy against this invasive species.
What should I do if I spot Old Man’s Beard on my property?
The Canterbury Regional Pest Management Plan requires land occupiers to eradicate Old Man’s Beard infestations covering less than 100m² and any infestations within 20m of a neighbouring property. Failure to comply with these regulations may result in legal consequences. The regional plan also allows authorized personnel to enter and inspect properties to ensure compliance with the Pest Management Plan’s rules, determining the individuals responsible for containing the pest both legally and financially.
For areas identified by Environment Canterbury as requiring control under the site-management program, the regional council will take the lead in achieving the desired level of Old Man’s Beard control. In many cases, the funding may be available from ECan. Old Man’s Beard poses a risk of seed dispersal to neighbouring areas, particularly those with significant biodiversity value.
What is Wai-Ora doing to control Old Man’s Beard?
Can Wai-Ora help me on my property?
Yes, Wai-Ora’s experienced teams of Ecological Contractors are available to help you identify, monitor, and contain or eradicate Old Man’s Beard on your property. Contact Tania Edwards Our Manager of Ecological Contracting to arrange a site visit.
