Clematis Invasive: A Growing Problem

Clematis is a beautiful flowering plant that is popular among gardeners worldwide. However, in recent years, the plant has become increasingly invasive in certain regions, causing ecological and economic damages. As a result, many gardeners are wondering how to deal with this problem. In this article, we will explore the issue of clematis invasiveness and provide tips and solutions for managing it.

What Is Clematis?

Clematis is a genus of approximately 300 species of flowering plants in the family Ranunculaceae. These plants are known for their showy flowers, which come in a variety of colors and shapes. They are native to many parts of the world, including Europe, Asia, and North America. Some species of clematis are highly valued in horticulture, often grown as ornamental plants in gardens and landscapes.

The Problem with Clematis Invasiveness

While clematis is a beloved plant by many, some species can be highly invasive. Invasive plants are those that are not native to a particular region and have the potential to cause significant harm to the environment, economy or human health. When these species are introduced into a new area, they can spread quickly and outcompete native plants for resources, disrupting entire ecosystems.

Clematis is considered invasive in many parts of the United States, including the Pacific Northwest, the Southeast, and the Northeast. The most commonly invasive species are Clematis vitalba (Old Man's Beard), Clematis terniflora (Sweet Autumn Clematis) and Clematis orientalis (Oriental Virginsbower). These species grow rapidly and can take over natural areas, agricultural lands, and even residential gardens.

How Clematis Becomes Invasive

Clematis becomes invasive when it is introduced to a new area where there are no natural predators or environmental factors to control its growth. For example, in the Pacific Northwest, clematis can grow up to 20 feet tall and form dense, impenetrable thickets that choke out native vegetation.

Another factor contributing to the invasiveness of clematis is its ability to reproduce quickly. Clematis produces a large number of seeds per plant, which can be easily dispersed by wind, water, wildlife or human activities such as gardening. Once these seeds germinate, they grow rapidly and produce more seeds, creating a cycle of rapid reproduction that can quickly overwhelm an ecosystem.

Signs of Invasive Clematis

Identifying invasive clematis can be challenging, as the plant can look similar to non-invasive species. However, there are some signs to look for. Invasive clematis typically grows taller and thicker than non-invasive species, forming a dense canopy that shades out other plants. It may also have larger leaves, thicker stems, and more extensive root systems. Additionally, invasive clematis often blooms earlier and for longer periods than non-invasive species, producing more flowers.

How to Manage Invasive Clematis

If you have identified an invasive clematis growing in your garden or natural area, there are several steps you can take to manage its spread.

Mechanical Control

One way to control invasive clematis is through mechanical means, such as hand-pulling or cutting the plant back. This method is best used for small infestations or in areas where chemical herbicides cannot be used safely. Be sure to wear gloves and protective clothing when handling clematis, as the plant can cause skin irritation.

Chemical Control

Chemical herbicides are also effective in controlling invasive clematis. Glyphosate-based herbicides are commonly used and can be applied directly to the plant or sprayed on the leaves. However, be sure to follow all safety precautions and read the label carefully before using any herbicide.

Biological Control

Biological control involves introducing natural predators or pathogens that will target invasive clematis without harming other plants. This method is still under development, and there are currently no widely available biological controls for clematis.

Prevention

Preventing clematis from becoming invasive is the most effective way to manage the problem. If you are planning to plant clematis in your garden, choose non-invasive species such as Clematis Montana or Clematis Viticella varieties. Avoid planting invasive species, and be sure to dispose of any unwanted clematis materials, such as seeds or cuttings, responsibly.

Frequently Asked Questions (FAQs)

Q1: Can I still grow clematis if I live in an area where it is invasive?

Yes, you can still grow clematis, but you should choose non-invasive species and take steps to prevent their spread.

Q2: How do I identify invasive clematis?

Invasive clematis typically grows taller and thicker than non-invasive species, forms a dense canopy that shades out other plants, has larger leaves, thicker stems, and more extensive root systems. It blooms earlier and for longer periods than non-invasive species, producing more flowers.

Q3: Is it safe to use chemical herbicides to control invasive clematis?

Yes, it is safe to use chemical herbicides if you follow all safety precautions and read the label carefully before using.

Q4: Can I compost invasive clematis plant materials?

No, you should not compost invasive clematis plant materials as they may contain viable seeds that can spread through the compost.

Q5: How long does it take for clematis to become invasive?

It depends on the species of clematis and the environmental conditions. Some species can become invasive in just a few years, while others may take longer.


Invasive clematis is a growing problem in many parts of the world. However, with proper management techniques and prevention measures, we can limit its spread and protect our native ecosystems. By choosing non-invasive clematis species and taking steps to prevent their spread, we can continue to enjoy these beautiful plants without causing harm.