Some trees give so much shade that grass has trouble growing beneath them. However, there are some ways to get grass below your trees if you are determined.
So, how do you grow grass under trees? First, prepare the soil with the proper pH and nutrients. Next, choose shade-tolerant grass varieties. Then, make sure to water properly and mow grass at the proper height (3 inches). Finally, prune trees with thick canopies, or cut them down and replace them with shorter, less dense trees.
Of course, if it is too shady, you might just have to settle for mulch – or a different type of ground cover entirely.
In this article, we’ll talk about how to get grass to grow under trees. We’ll also go over some alternatives, just in case you have trouble getting grass to grow.
Let’s get started.
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How To Grow Grass Under Trees
When grass and trees grow in the same soil, they compete with each other for light, water, and nutrients. So, you will have to strike a balance to ensure that both can grow in the same place.
To encourage grass to grow under trees, there are 5 basic steps to take:
- Prepare the soil for grass (get a soil test, adjust the pH, and fertilize as needed)
- Choose shade tolerant grass varieties (fine fescues for dry soil, rough bluegrass for damp soil)
- Water properly (water deeply and irregularly, and water early in the day)
- Mow at the correct height (3 inches is ideal – too short will burn grass and reduce growth)
- Prune or replace trees (this will allow more sunlight through to the grass)
Let’s take a closer look at each of these steps, starting with soil preparation.
Prepare The Soil For Growing Grass
Before you try to grow grass under a tree (or anywhere else), it is important to get these things right:
- Soil texture (compact or loose)
- Soil drainage (water retention)
- Soil pH (acidity)
- Soil Nutrients (fertilizer)
If the soil is too compacted at the surface, grass will have trouble growing there with its shallow roots. Do a little digging, but be careful to avoid damaging tree roots.
Many types of grass do not like soil that stays too wet, so good drainage is important. Mix a little compost or aged manure into the soil to add organic material and improve drainage.
It is also helpful to get a soil test before you amend your soil pH or nutrient levels. A soil test tells you the pH and nutrient levels.
If you send a soil sample to an agricultural extension office, they can give you recommendations if you tell them that you are growing grass.
If your soil is too acidic (low pH), you can use lime or dolomitic lime to increase pH. If your soil is too alkaline (high pH), you can use sulfur or iron sulfate to decrease pH.
The amount you need will depend on the current pH and the desired pH, as well as the area you are trying to adjust. According to the University of Missouri Extension, the ideal pH for grass is slightly acidic to slightly alkaline (6.0 to 7.5).
To ensure that grass has a good chance to grow, it is important to provide the necessary nutrients in the proper amounts.
Avoid high nitrogen fertilizer near trees – this promotes lush green growth of leaves that will shade out your grass. (You can learn about low-nitrogen fertilizers here).
The University of Vermont Extension suggests using a fertilizer that is high in potassium. This encourages stronger blades of grass and improves disease resistance.
Note: potassium, or K, is the third element out of NPK listed on a fertilizer package. So a bag of 8-3-9 fertilizer has 9% potassium by weight.
(You can learn more about fertilizer numbers here.)
Finally, be sure to rake away debris from the grass under your trees, as necessary. According to the University of Missouri Extension, too much organic matter buildup (from fallen leaves, pine needles, etc.) will discourage grass growth.
Choose The Best Grass Varieties For Shade
Now that your soil is ready, it’s time to choose grass varieties that are most likely to grow well in a shady area under trees.
According to the University of Vermont Extension, some of the most shade tolerant grasses are:
- Fine fescues – these grasses prefer drier soil. Some varieties include red fescue, Chewing fescue, hard fescue, and sheep fescue.
- Rough bluegrass – these grasses can tolerate moist soil. Some varieties include Sabre, supina, Kentucky (Glade or America), and rough stalk.
Remember that you can also use a blend of different types of grass seed to give you some variety. For example, you can try a mix of 50% rough stalk bluegrass and 50% ryegrass for heavily shaded areas.
Also, keep in mind that some grass varieties need lots of sunlight, and they will do poorly in shade.
Avoid the following grasses under trees or in shady areas:
- Bermudagrass
- Zoysiagrass
- Buffalograss
[Note: this list is not exhaustive; any grass that is not shade-tolerant should be avoided when planting under trees].
Water Your Grass Properly
Once the soil is ready and you have shade-tolerant grass seed planted, it is time to water it in. As with many things in gardening, it is possible to have too much of a good thing when it comes to water.
Too much water will drown your grass, eventually causing root rot (due to waterlogged soil). Wet soil conditions will also encourage the growth of moss in shady areas under trees (moss also tends to grow better in acidic soil).
It is a good idea to water your grass (and other plants) deeply but infrequently. This will encourage stronger root systems for grass (and for other plants as well).
Providing a small amount of water daily will not encourage a strong root system in plants. It also wastes water, since a good amount will be lost to evaporation if it doesn’t soak far down into the soil.
According to the University of New Hampshire Extension, watering late in the day can promote disease if grass and soil stays wet overnight. So, try to water early and give the grass time to dry before nightfall.
Mow Grass At The Correct Height
Once your grass starts growing tall, it is tempting to mow it down to keep it looking neat. However, try to resist the temptation to cut it too short!
If you mow your grass too low, it will have trouble growing back. The blades of grass absorb sunlight for photosynthesis, so shorter blades means less energy production.
This is even more critical in a shady area under a tree, where light is already hard to come by.
(You could also try using electric lawn mowing robots – you can learn more here).
Prune Tree Branches To Let Light Through To Grass
According to the University of Vermont Extension, most grasses need at least 4 to 6 hours per day of direct sunlight. Luckily, there is a way to help get more sunlight to the grass under your trees: pruning off some branches.
Many fruit trees benefit from regular pruning, but you can make almost any tree look neater with some sensible pruning.
Don’t overdo it with pruning, though. When you do prune, use clean shears and sanitize your tools after each tree to avoid spreading any diseases that may be present.
If pruning just won’t cut it, another option is to remove some of your taller trees entirely. Trees with dense canopies (such as oak trees, maple trees, or conifers like pine trees) filter out most of the blue light from sunlight, which reduces photosynthesis and plant growth.
It is also difficult to grow grass under sweet gum and pin oak trees.
If you cannot bear to be completely without trees, replace the tall ones with shorter trees that have a limited height (for example, dwarf fruit trees).
Also, remember that trees with shallow roots (such as beech, maple, and willow) will compete with grass roots, so choose trees with deeper roots instead.
5 Alternatives To Grass Under Trees (Ground Cover Plants For Shade)
You can always mulch under a tree if the area is too shady and you don’t want to prune or cut down and replace the tree. (Just remember to avoid mulch volcanoes or a layer of mulch that is too thick).
However, if you don’t like the idea of a mulch bed under your tree, here are some ideas for what you can plant instead of grass:
- Alpine Strawberry – this perennial ground cover plant produces small white flowers (and eventually fruit!) It is hardy to Zone 4a (temperatures down to -30 degrees Fahrenheit or -34 Celsius). You can learn more about Alpine Strawberry from the National Gardening Association’s Plant Database.
- Cinnamon Fern – this perennial ground cover fern tolerates both shade and damp soil. It can also tolerate acidic soil, down to a pH of 4.6. You can learn more about Cinnamon Fern from the National Gardening Association’s Plant Database.
- Cranesbill – this perennial ground cover plant produces small flowers that white, pink, purple, blue, or other colors). It prefers moderate to dry soil, and it can tolerate a soil pH from 6.0 to 8.0. You can learn more about Cranesbill from the National Gardening Association’s Plant Database.
- Crested Leopard Plant – this perennial ground cover plant produces small yellow flowers in summer or early fall. It needs moderate moisture levels and can tolerate a soil pH of 5.6 to 6.8. You can learn more about Crested Leopard Plant from the National Gardening Association’s Plant Database.
- Hellebore – this perennial ground cover plant produces small flowers that are blue, pink, or white. It needs moderate moisture and can tolerate a soil pH down to 5.5. You can learn more about Hellebore from the National Gardening Association’s Plant Database.
For more ideas, you can find 10 ground cover plants for shade in this article.
If you prefer flowering plants, you can find 10 that grow in shade here.
Conclusion
Now you know how to grow grass under trees, or how to choose an alternative if it is just too shady for grass.
You can also find some drought tolerant grasses here.
If you want to get rid of grass somewhere in your yard or garden, learn how to do it here.
I hope you found this article helpful. If so, please share it with someone who can use the information.
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~Jonathon