Mature shade trees, shrubs, bushes and flower beds make for a beautiful landscape and provide a more comfortable environment in the heat of summer. Maintaining a quality lawn in the shade is challenging but in most cases is quite possible as long as some sunlight reaches the ground.
So how do I improve a weak lawn struggling to thrive in the shade ?
- Turf management practices. Optimize your irrigation, cutting and fertilization.
- Increase the light reaching your lawn.
- Plant grass seed appropriate for your growing conditions and the type of lawn you desire.
- Amend the soil.
Turf management Practices:
First and foremost, proper management practices should be adhered to. It is possible that whatever grass you have growing in your shaded area is well adapted and only needs a little TLC. Proper watering, mowing, fertilizing and weed control requires attention to detail for the shady lawn. More than likely, you will have to maintain a shady lawn a little differently than one in greater sunlight.
Water deeply but infrequently during dry periods. Because a shady lawn is not exposed to the heat of direct sunlight, the soil in shade may not absorb moisture as quickly and will not dry as fast due to decreased evaporation. Ordinarily, shaded areas of a lawn contain more moisture thus requiring less watering. However some trees have extensive root systems, consuming water, causing stress in the shade, occasionally before it shows up in sunny areas. You will need to watch those areas for signs of drought stress.
Adjust mowing practices to suit the type of grass you are growing in the shade. In most instances, the cutting height should be higher than it would be for that particular type of grass in the open sun. A lawn growing in shade needs a larger leaf surface to encourage deep and more extensive rooting which allow the turf to better compete with the tree roots for water and nutrients.
Grasses growing in shaded areas may require one-half to two-thirds as much nitrogen as grasses growing in full sun. The reason is that reduced sunlight impedes the photosynthesizing process, so too much fertilizer applied to grass under shade conditions can render it less able to manage nutrients. Additionally, reducing the amount of fertilizer to a shady may reduce the incidence of disease. Fertilize shady locations at the same time as turf grown in the sun only in lesser quantities.
Increase the light reaching your lawn:
Growing grass under the canopy of trees may require that branches be removed up to 8 feet or higher. Try to open the canopy as much as possible without destroying the health and beauty of your tree. Shrubs and bushes should be pruned to allow more light to reach the lawn and to allow better air circulation which reduces disease issues.
Choice of turf types and cultivars:
There are several types of grasses grown in Northern lawns. Kentucky Blue, Tall Fescue, Rye, and Fine Fescue are most common as either pure stands or mixtures. All can thrive under partial shade conditions. Fescue does better in denser shade with the Fine Fescues performing the best. There are a few shade tolerant KBG cultivators. Plant high quality grass seed mix obtained from a professional lawn supplier or home center, which sell grass varieties suited for your area. Do your best to match the grass type you have in the rest of your lawn. In deeper shaded areas, an equal blend of Hard, Chewings, and Creeping Red Fescue works well and is often recommended. If your lawn consists of elite cultivars, then you may wish to consult NTEP trials in your area in order to construct a custom blend consistent with the highest quality lawns. Fine Fescues prefer drier soils and do not tolerate constantly wet soils. Rough bluegrass (Poa Trivalis) is available and performs best in shaded areas that are constantly moist. Trivalis is often considered a weed and could easily spread into the finer areas of your lawn and is not specifically recommended. For best results, seed the shady area in early fall. Gradually the leaves from the surrounding trees begin to thin, allowing more sun to reach the surface, giving the new grass a strong start. The second best time to seed shady areas is spring, before the trees have leafed out.
Amend the soil:
Any lawn will perform it’s best with a great topsoil rich in organic material. If your soil is mostly sand or mostly clay, then try to incorporate more OM into the soil. Do not expect to grow a decent lawn in compacted soil, pure sand, or clay as hard as concrete.
Provide good soil drainage and aeration to allow adequate penetration of nutrients, water, and air into the soil. Applications of compost, mulch mowing of autumn leaves, organic fertilizers, and mulching grass clippings all contribute to higher OM content in the soil. For maximum tolerance to environmental stress, maintain optimum soil pH and nutrient levels as recommended by soil tests. Many of the same disease problems exist in both shady and sunny areas. Those diseases associated with high moisture and/or high humidity may be more serious in shady areas because air movement is reduced and surface moisture remains longer. Good cultivar selection and good management practices should reduce the severity of these diseases.
Failure to achieve satisfactory results:
If you follow all these steps and, after a full growing season, your lawn is not satisfactory, there may be too little sunlight to support turfgrass. You may want to consider alternative landscape strategies, such as tree removal, planting ground cover, or installing permanent decorative mulch.
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