Why Can’t I Grow Grass Under My Tree?

Why Can’t I Grow Grass Under My Tree

If you’ve ever tried to grow a lush, green lawn under a mature tree, you’ve likely encountered some challenges. The reality is that growing grass under trees can be an uphill battle. There are several key reasons why it’s so tricky, but understanding the underlying causes can help you find the best solution for your landscape.

Shade: The Grass Killer

One of the primary reasons grass struggles under trees is the lack of sunlight. Trees, huge, mature ones, cast significant shade that blocks the sun’s rays from reaching the ground below. Most common lawn grasses require at least 6 hours of direct sunlight per day to thrive. When that sunlight is blocked, the grass simply can’t photosynthesize effectively and begins to decline.

“The more mature the tree, the more shade it casts, making it increasingly difficult for grass to grow underneath.”

The Battle for Resources

In addition to the shade issue, tree roots also compete with grass for essential resources like moisture and nutrients in the soil. As the tree grows larger, its root system becomes more dominant and deprives the grass of the water and nutrients it needs to survive.

This competition for resources is a losing battle for the grass, as trees are typically more aggressive and efficient at extracting what they need from the soil. Over time, the grass simply can’t keep up and begins to thin out or die off entirely.

Leaf Litter: The Grass Smotherer

Another challenge posed by trees is the accumulation of fallen leaves, or “leaf litter,” on the ground. As leaves drop from the tree canopy, they can form a thick layer that blocks sunlight and smothers the grass underneath. This leaf litter can also prevent water and air from reaching the soil, further stressing the grass.

Mowing Challenges

Maintaining the grass under a tree can also be tricky from a mowing perspective. Ideally, grass under trees should be mowed at a higher height to help retain moisture. However, this can be difficult to achieve consistently, as the uneven terrain and obstacles posed by the tree trunk and roots make it hard to mow evenly.

Strategies for Success

While growing a lush, green lawn under a tree can be challenging, there are some strategies you can try to improve the chances of success:

Choose Shade-Tolerant Grass Varieties

One of the most important steps is to select grass species that are more tolerant of shady conditions. Some good options include:

Grass TypeShade Tolerance
Fine FescueHigh
Tall FescueModerate to High
Perennial RyegrassModerate
Kentucky BluegrassLow

By choosing the right grass type, you’ll give your lawn a better chance of thriving in the limited sunlight under the tree.

Prune the Tree Canopy

Another strategy is to prune the lower branches of the tree to allow more sunlight to reach the ground below. This can be an effective way to increase the amount of direct sunlight the grass receives, which can help it grow more vigorously.

Water and Fertilize Regularly

To compensate for the competition with tree roots, be sure to water the grass under the tree more frequently than the rest of your lawn. This can help ensure the grass has access to the moisture it needs.

Additionally, applying a balanced lawn fertilizer more often can help provide the necessary nutrients to the grass, which the tree’s root system may deplete.

Rake Leaves Regularly

Staying on top of raking up fallen leaves is also crucial for maintaining grass under a tree. A thick layer of leaf litter can block sunlight, smother the grass, and prevent water and air from reaching the soil.

Raise the Mowing Height

As mentioned earlier, mowing the grass under a tree at a higher height can help it retain moisture and withstand shady conditions. Aim for a mowing height of 3-4 inches rather than the typical 2-3 inches for the rest of your lawn.

When Grass Isn’t the Answer

In some cases, despite your best efforts, the conditions under a mature tree may simply be too challenging for grass to thrive. In these situations, it may be better to abandon the idea of a lush, green lawn and instead opt for a shade-tolerant ground cover or mulch.

Ground covers like:

  • Pachysandra
  • Vinca
  • Ivy
  • Ajuga

It can provide a low-maintenance, attractive alternative to grass that is better suited to the shady, resource-depleted conditions under a tree.

Alternatively, a layer of organic mulch, such as wood chips or shredded bark, can help suppress weeds, retain moisture, and improve the soil conditions for any plants you choose to grow in that area.


Growing a healthy lawn under a mature tree can be a real challenge, but understanding the underlying causes can help you make informed decisions about the best approach for your landscape. By choosing suitable grass varieties, managing the tree’s canopy and roots, and considering alternative ground covers, you can find a solution that works for your unique situation.

Remember, the key is to work with the conditions, not against them. With a bit of creativity and persistence, you can create a beautiful, thriving landscape that coexists harmoniously with your beloved tree.