Many factors make it difficult for lawns to grow properly in the shade: plants don’t get enough sunlight to grow properly, diseases associated with shaded areas are more likely to affect groundcover plants that lack sunlight, and lawns must compete with tree roots for water and nutrients.
When soil compaction or poor drainage results in shallow root systems, or some trees are born with shallow root systems, such as silver maple, it is particularly difficult to compete with tree roots.
In order to successfully grow a lawn in the shade, you need to use the same management techniques used to grow lawns in the sun. One published outline recommends management policies and recommends use in areas where grass will not grow.
一、Grass seed selection
The most important factor in maintaining a healthy lawn is grass seed selection. Planting the right grass species can make the difference between a thriving lawn and one that will wilt and die even if you are careful. For example, bluegrass, a popular grass species, does very poorly in shaded environments. Good tall fescue can adapt to shady conditions but cannot tolerate excessive trampling. Lying bluegrass and thick-stemmed bluegrass require moist soil to manage well.
The key to keeping your lawn thriving in the shade is to choose a seed mix that combines several shade-tolerant species and uses 2-4 different species of each variety together. Some species survive because they can grow in light sunlight, while others are better able to resist disease. A combination of grass species helps eliminate disease or climate-induced decay throughout the landscape.
How good a seed mix is for your site depends on the amount of available moisture. Most lawns are sown with a mixture of various bluegrass varieties and are not suitable for planting in a shaded environment. If a mix containing bluegrass and bluegrass mixed with fine fescue is used, it can be used in shady conditions.
二、 Management of lawn establishment
2.1 Fertilization
Lawns grown in the shade require fewer nutrients than lawns grown in the sun. Shady lawns require no more than 2 pounds of nitrogen fertilizer per 1,000 square feet annually. Lawns grown in the sun use about half as much. High-efficiency fertilizers can weaken the lawn or render them unavailable to plants. The best time to apply fertilizer is when your plants need nutrients the most. There are three timings for lawns: late spring, late summer and late fall. Fertilizer should be applied twice each season, with 1 pound of nitrogen per 1,000 square feet in mid-May and the same amount in the last week of August or the first week of September. The schedule provides a better quality lawn during the summer by applying 2/3 pound of nitrogen fertilizer per 1,000 square feet in mid-May, early July, and mid-to-early October.
2.2 Pruning and transportation
For lawns growing in shady areas, a mowing height of 3-4 inches is recommended. This height is slightly higher than the recommended height of 2(1/2)-3(1/2) inches for lawns growing in the sun. For shaded and sunny areas, set the mowing height to 3-3 (1/2) inches to coordinate the lawn in both areas. Cutting grass too short can impair photosynthesis in plant leaf tissue. This is especially important for grasses growing in shade because they have relatively few leaves. When mowing your lawn, it’s best to keep it no more than one-third of the way through the blades. For shady lawns, mow the grass when it reaches 4 to 5 inches tall. Pruning more than one-third of the leaves will temporarily stop root growth and weaken the plant’s root growth.
If possible, restrict traffic to a heavily shady lawn so it can slowly recover from its own damage. A height of 3-4 inches also helps protect the plant’s growing point by reducing traffic-related damage by leaving more leaf tissue behind.
2.3 Growth regulators
Plant growth regulators can significantly improve the quality of lawns in shaded environments. They work by slowing leaf elongation, which provides more nutrients for root growth. After comparison, it was found that the treated plants were darker in color, with lush leaves and dense root systems, while the untreated plants had grayish white, sparse leaves and insufficient root systems. Look for the right fertilizers on the market for plants in shaded environments, including growth regulators. Another effective growth regulator, trinexapac-ethyl can be used in professional lawn care and landscape composition.
2.4 Irrigation
Lawns should be watered with 1 inch of water weekly. For plants, watering thoroughly, to a depth of 5-6 inches, is better than frequent light irrigations. Shallow-rooted lawns and trees should be watered frequently as they are more susceptible to drought. Soil type and compaction will affect how much water your plants need. Sandy soils contain less water than loams and clays, so they require frequent watering. Use small amounts of water (about 1/2 inch at a time) for sandy and non-compacted soils, since these soils cannot hold the same amount of water as loams and compacted soils.
To determine how deeply to spray water on your site, place a coffee can under the spray and observe how long it takes to fill up to the recommended amount. Most sprinklers take 2 hours to cover 1 inch of water. Irrigating your lawn in the morning gives it a chance to dry out throughout the day. Watering in the afternoon or evening increases the likelihood of disease by extending the time the leaves are wet.
2.5 Disease
Even when growing in full sun, lawns in the shade can die or be attacked by several diseases that weaken their growth. Shade environments have extremely mild temperatures, less wind movement, and increased relative humidity. At the same time, after dew, rainfall or irrigation, the time that water stays on the leaf surface will also be extended. These conditions favor the growth of many fungi and cause lawn diseases. As with all lawn ailments, the best solution is to plant a shade-tolerant lawn and modify the environment by pruning trees to increase light and air movement. Powdery mildew is one of the most common diseases of shade lawns. The white, powdery fungus is easily visible when it affects leaves. The fungus only survives on the surface of the leaves and is easily rubbed off. Powdery mildew in lawns cannot be killed directly, but it can completely prevent severe infection from causing plant death. Bluegrass is more susceptible to this disease than other grass species. Some fungicides are labeled to control powdery mildew, but they are of little use because powdery mildew relapses within 7-28 days. Watering at night should be avoided.
Brown spot, also called powdery snow mold, is another common shade disease. This fungus grows better in cool, moist conditions and occurs throughout the growing season in Wisconsin. The hyphae of this fungus occasionally form small clumps of white that gradually turn orange in the lawn. Severe infestations can kill your lawn. Fungicides can be used, but your best option is one that targets all diseases in shady environments: Prune trees to allow them more sunlight and air movement.
Other diseases may also affect the growth of shady lawns, including leaf spot (also known as worms or worms), rust, and more.
2.6 Moss
Moss indicates unfavorable conditions for lawn growth. Moss does not crowd out lawn growth, but lawns will die where moss grows. Common causes of moss in lawns are excessive shade and its poor ability to reproduce. Before you can successfully establish a lawn where moss grows, you need to change the environment to ensure it provides enough light, the right moisture, and fertility for the lawn to grow.
三、 grass choices
Some places are not conducive to growing lawns: There may not be enough light, or too many tree roots are growing nearby, or there may be too much traffic that can cause plant death. Whatever the reason, consider planting weeds in these areas instead of building lawns. For high traffic areas, use shredded bark or small rocks. For other areas, consider planting a shade-tolerant ground cover.
四、Managing trees in shade
4.1 Prune trees to increase light and air flow
One way to improve lawns growing in shade is to prune trees to allow more light to pass through. Prune branches of deciduous trees to at least 10 feet from the ground. This method usually only works on deciduous trees; coniferous trees may lose their attractiveness if their lower branches are pruned. Mowing increases the amount of light your lawn receives and increases air movement, which reduces the risk of disease. Pruning is most effective when there is only one tree, but may not be effective when there are many trees in the shade. Using correct pruning techniques can reduce potential disease. It is recommended to hire a professional to prune a large tree or you will lose that tree due to damage or disease caused by improper pruning.
4.2 Remove fallen leaves
Sunny days and low temperatures in the fall provide ideal conditions for lawn growth. If the lawn is covered with fallen leaves during this important growth period, the plant will not be able to produce and store enough energy through the winter. Fallen leaves are always removed or piled into piles throughout the fall. If the leaves fall evenly on the grass, the lawn will not be tightly covered with fallen leaves.
4.3 Protect tree trunks and roots when pruning
Physical damage to the trunk or roots creates entry points for pathogens that can cause tree weakening or death. To prevent lawnmower-induced damage, consider placing mulch around the base of the tree trunk and over the shallow roots. Before mulching, pull the grass out by hand or kill it with a non-selective herbicide such as glyphosate.
Post time: Aug-01-2024