Why Won’t my Grass Grown in the Shade?
Now that the grass is greening up and summer is almost upon us, many people notice that their grass isn’t growing in the shady parts of the yard. By taking several steps, you can increase your grass coverage in these shady areas.
Growing grass in the shade is different than growing it in the full sun. Often times, we have trees and shrubs in our yard that provide shade for our hot summer days, but then we see bare spots in our lawn. What can you do to address this problem?
Increase sunlight to the grass:
Grass needs 4 hours or more of sunlight to successfully grow. To increase sunlight availability under trees, apply a rule of thumb by trimming trees so that one-third of the trunk is bare and 2/3 is limbed with branches. If you can carefully prune branches so that they are 6 to 8 feet above the turf, this can greatly increase the sunlight to the soil. It will also allow for more air circulation, which will reduce disease problems with the grass.
Don’t prune branches higher than 1/3 of the height, that will create a completely different set of problems. Remember you can prune as long as the tree is fully leafed or completely dormant. Evergreens aren’t pruned in this way. They operate differently, but evergreens often are smaller and shade the grass in a smaller area.
Photosynthesis is how plants make food. If grass has less sunlight it has less food. By raising the mowing height by ½ to 1 inch, you are letting the plant be able to make more food, as well as allowing roots to grow deeper in the soil. In the shade, grass is in competition for water and nutrients, so don’t put your grass on a diet!
When watering turf, it is better to water infrequently, but deeply. Apply an inch of water in the early morning. Use an impact sprinkler or other method, letting the sprinklers run until you measure an inch of water has been applied. You can use a measuring cup, can or other container to hold the water. By watering deeply, you are encouraging grass roots to grow deeply, reducing compaction and minimize the time grass leaves are wet. The longer leaves are wet, the more increased chance for disease problems. Deep, infrequent watering is beneficial as the grass and trees are competing for water. Deep roots are especially important during dry spells.
If you fertilize your grass, apply at the same time as the rest of your lawn. Apply less fertilizer than recommended. This is because the grass is using less nutrients. Be careful when fertilizing Centipede grass. Too much fertilizer is worse than none for this type of grass.
Plant shade tolerant grass:
If you are starting your lawn, or want to try another strategy, plant varieties that are better adapted to shade. St. Augustine and Zoysia grass are more shade tolerant than Bermuda and Centipede grass. Both St. Augustine and Zoysia can be started as sod, sprigs or plugs. If Centipede or Bermuda is not growing, you can interplant one of these grasses and they will fill in the shade areas. Best time to plant St. Augustine or Zoysia is in March through May.
For more information, contact Shannon Newton at the Hoke County Cooperative Extension Center at (910)875-3461. You may visit NC State University Turf Files at: http://turffiles.ncsu.edu.