What Plants Invasive Will Grow Under a Black Walnut Tree

Black walnut trees are not only prized for their valuable timber but also for their ornamental value. Their dark green foliage and unique bark make them stand out amongst other trees in a landscape. However, one thing to note when planting under a black walnut tree is that not all plants are compatible with it. Black walnut trees have a secret weapon- they secrete a chemical called juglone that impairs the growth of many plants. Therefore, it is crucial to choose plants that are tolerant to juglone. In this article, we will dive into some invasive plants that can grow under a black walnut tree.

1. Japanese Knotweed

Japanese knotweed is an invasive plant that is known to grow aggressively under black walnut trees. This plant can grow up to 10 feet tall and can quickly spread to nearby areas, causing damage to roads, buildings, and other structures. The presence of juglone does not seem to have any effect on the growth of Japanese knotweed. This invasive plant is difficult to control and can only be eradicated by using a combination of methods such as herbicides, manual removal, and regular mowing.

2. Garlic Mustard

Garlic mustard is another invasive plant that grows well under black walnut trees. This plant is known for its resilience and can survive in a wide range of conditions. The presence of juglone does not seem to deter the growth of garlic mustard. This invasive plant has a toxic effect on other plants growing in its vicinity, causing them to wilt and die. In addition, the plant is notorious for disrupting the natural balance of ecosystems, creating a monoculture that crowds out indigenous vegetation.

3. Japanese Stiltgrass

Japanese stiltgrass is an invasive plant that is gradually spreading throughout the United States. This plant is known for its rapid growth and ability to take over large areas. The presence of juglone does not seem to affect the growth of Japanese stiltgrass. This invasive plant can quickly cover the soil under the black walnut tree, making it difficult for other plants to grow. Japanese stiltgrass can be controlled by manual removal and regular mowing.

4. Multiflora Rose

Multiflora rose is an invasive plant that can grow up to 15 feet tall and 10 feet wide. It is known for its thorny stems and quick growth. The presence of juglone does not seem to affect the growth of multiflora rose. This invasive plant can quickly take over an area under the black walnut tree, making it difficult for other plants to grow. Multiflora rose is difficult to control, and it is recommended to use a combination of methods such as manual removal, regular mowing, and herbicides.

Conclusion

It is important to note that not all plants are compatible with black walnut trees. The presence of juglone can severely impair the growth of many plants. It is essential to select plants that are tolerant to juglone and are not invasive. Invasive plants can cause significant damage to the environment and other native plants. Regular monitoring and eradicating invasive plants are necessary to maintain a healthy ecosystem.