Why Don't Plants Grow Under Trees?

Have you ever noticed that plants often struggle to grow under trees? This phenomenon is a common occurrence in gardens, forests, and other natural areas. There are several reasons why plants may have difficulty growing under trees, which we'll explore in this article.

Shade

The most obvious reason why plants don't grow under trees is the lack of light. Trees produce large canopies that block out much of the sunlight, making it difficult for smaller plants to thrive. Sun-loving plants, such as tomatoes and cucumbers, require six to eight hours of direct sunlight a day to produce a healthy crop. In contrast, most tree canopies only allow dappled sunlight to filter through to the ground.

Moreover, some trees have leaves that create a dense shade under which nothing will grow. These trees are usually tall and broad, such as oak and maple trees, which have deeply lobed, dense leaves. Plants that grow under such trees often end up etiolated or spindly, as they stretch towards the limited sunshine.

Competition for Water and Nutrients

Trees have vast root systems that soak up the water and nutrients in the soil. As a result, smaller plants growing under trees often struggle to access these essential resources, making it difficult for them to grow and thrive.

The roots of trees grow deeper and wider than those of smaller plants, often competing with other plants for water and nutrients in the soil. They can also release chemicals or allelopathic compounds that inhibit the growth of other plants growing nearby. These compounds can affect the plant's ability to germinate, grow, and develop normally, making it harder for them to compete with the trees.

Acidic Soil

Another reason why plants may struggle to grow under trees is due to the acidity of the soil. Trees, especially evergreens and pine trees, produce needles and leaves that can create acidic soil conditions over time. This acidity could also be caused by decomposing organic matter, such as dead leaves and branches, that falls from the trees and accumulates under the canopy.

Most plants require a slightly alkaline environment to thrive, with a pH level of between 6.0 and 7.0. However, acidic soil conditions can prevent proper nutrient uptake, as well as causing toxicity problems that damage the plant's roots and impede growth.

Conclusion

In conclusion, there are several reasons why plants may struggle to grow under trees, including lack of light, competition for water and nutrients, and acidic soil. While it may be difficult to grow plants under trees, it's still possible with the right selection of plants that can tolerate the unique conditions under the canopy. Shade-loving plants, such as ferns, hostas, and impatiens, can grow well in areas with minimal sunlight, while groundcovers like ajuga, vinca, and lamium can thrive in dry shade conditions. Understanding the unique challenges of growing under trees can help gardeners make informed decisions when planting in these challenging areas.