How to Grow Grass Under Oak Trees

If you love your oak tree but you’re wondering why the grass underneath it is looking shabby, do not worry. Grass doesn’t always grow well under trees, but there are things you can do about it that aren’t difficult and will produce results.

To help grow the grass under your oak tree it’s important to properly prune the tree, choose the right mix of grass seed, and being careful when it comes to applying fertilizer.

Why Doesn’t Grass Do Well Under Oak Trees?

First of all, grass doesn’t always do well under any trees because grass needs a lot of direct sunlight in order to thrive. The bigger the tree, the less sunlight the grass gets. Other reasons include:

  • Less sun means less photosynthesis, which means less food for the grass.
  • Trees with large canopies, such as oak trees, mean that the grass near the tree has to compete with the tree roots for the nutrients from the water and the soil.

It isn’t that grass can’t grow underneath a tree; it’s just that it can’t thrive, spread, and get as green as it normally does.

Growing grass under oak trees isn’t impossible, in other words, but you do have to pay special attention to the process so that the results are what you want. You have to give the area underneath the trees a little TLC.

Grass near oak trunk
Yay It’s certainly possible to grow lush grass near oak trunks as displayed in this photo. The most important thing for this to happen is that sufficient light can hit the ground below the oak tree. Without sunlight, hardly anything will grow well…

What Can I Do to Get the Grass to Grow?

To get the grass under oak trees to grow and look great, it is going to need some extra attention. Follow these tips to get the best results:

  • Each fall, make sure that you keep all the leaves completely raked from under the tree.
  • In shady areas, don’t over-apply your nitrogen fertilizer; only apply it before the leaves drop in the fall or in the spring before the leaves appear.
  • Prune the lower branches to a height of around six feet.
  • Water your grass in the morning and only use enough water for the topsoil to be damp or wet.
  • When buying your grass seeds, make sure that you choose ones that are shade-tolerant.
  • When you mow, set the blades high so that the grass remains around three inches high.

The bottom line is that you want to do things that open up the space under the tree so that more sun can get to it. The more sun the area gets, the better the chance you’ll be able to keep nice-looking grass underneath the tree.

What If This Doesn’t Work?

Regardless of what you do, getting green grass to grow thickly underneath your oak tree may not work. If it doesn’t, don’t worry because you do have other options available to you.

One of the things you can do is take the grass out and landscape the area underneath the tree. If you do this, you’ll need to choose the right plants because if you don’t, you’ll have the same problems growing those plants that you did with the grass.

Below are a few plants that do well under oak trees, especially if you have dry summers:

  • California fescue (Festuca californica)
  • California iris (Iris douglasiana)
  • Coral bells (Heuchera spp.)
  • Creeping sage (Salvia sonomensis)
  • Deer grass (Muhlenbergia rigens)
  • Purple needlegrass (Nassella pulchra)
  • Wild lilac (Ceanothus spp.)
Wild Lilac Ceanothus Victoria
Oregon State University The Wild Lilac – Ceanothus ‘Victoria’ is a beautiful blue perennial that is very resistant against drought.

There are also plants that do well along the dripline of the tree, which is the area around the tree that the rain would naturally fall after it starts raining. These plants include the following:

  • Azaleas (Rhododendron)
  • Creeping mahonia (Mahonia repens)
  • Evergreen ribes (Ribes viburnifolium)
  • Manzanita (Arctostaphylos densiflora)
  • Wood rose (Rosa gymnocarpa)

If you plant these varieties underneath your oak tree, you’ll have to plant them roughly six feet from the trunk of the tree. In addition, make sure that you do not alter the soil level, compact the soil, or change any drainage patterns.

The section between the trunk of the tree and the dripline can, however, be accommodated with some mulch. Use organic mulch for the best results and never irrigate the area in the summer.

If you give that part of the tree a lot of water in the summer, it can fall victim to crown rot and even oak root fungus, so you can basically leave it alone during the summer months.