Lawns and Shade
Grass grown in shade often deteriorates over time, especially as trees in and around the lawn area increase in size. Sometimes grass that did well when a tree was first planted thins out as the tree approaches its mature size. Sometimes there is bare soil where grass once grew up to the trunk. Trees which have a dense canopy, like sugar and Norway maples, oaks, and beech, make it extremely difficult to grow an acceptable stand of grass underneath without limbing-up or pruning to the point of compromising their stately form.
Most turfgrasses need at least 4 to 6 hours of direct sun per day. Kentucky bluegrass and perennial ryegrass usually do best at a minimum of 8 hours of direct sun per day. If strategic pruning of limbs or branches still doesn’t allow enough sun to allow an acceptable bluegrass or ryegrass stand, a fescue grass may be a better option.
If at least 4 hours of sun are available, a fine-leaved fescue blend or a turf-type tall fescue blend could tolerate this much shade. If the conditions are wet or damp, a turf-type tall fescue will do better than a fined-leaved fescue. Either type is able to cope with shade conditions, but will also do better in full sun, so fescues may be used for an entire lawn area. Fine-leaved fescues suitable for shady lawns are: creeping red fescue, hard fescue, or Chewings fescue. Sometimes all three are sold together as a sun and shade blend.
For wet shaded areas, consider roughstalk bluegrass. This is a very fine textured grass that requires higher moisture, but will tolerate shade very well. However, it will not withstand traffic or wear. This is a specialty grass, so seed may not readily available in most stores. You may have to ask for a special order.
Grasses grown in shade require careful management as they will not have the ability to recover from stress as well as grasses grown in full sun. After establishment, they should be mown higher – three inches or higher – and fertilized less. Also, they will need less water than grass grown in the sun. One to two pounds of nitrogen per thousand square feet per year is sufficient for shade-grown grasses. Returning clippings can reduce the nitrogen needed by 1/3. Fine-leaved fescues often do well with only one pound of nitrogen per year per 1,000 square feet. Traffic should also be reduced over shaded lawn areas, and especially on fine-leaved fescues, since they are not tolerant to traffic in shade or sun. Careful turning with the mower (avoid sharp turns) when cutting shaded turf will prevent shallow rooted grass from being pulled out.
If the practices mentioned previously have been followed but the grass still remains thin, then something else may have to be planted in the worst areas. Consider using native shade- loving plants such as ferns, Jack-in-the-pulpit, tiarella (foamflower), trillium, Solomon’s seal, and dogwoods to make a woodland garden. Or try ground covers such as pachysandra, bugleweed (for moist shade), periwinkles (vinca), or others. With trees that simply cannot be pruned, consider mulching the area under the tree. Another option is to try a moss garden! That may be an attractive green alternative, especially when splashed with a native fern or two.
Article by Pamm Cooper
Turf Program Coordinator
University of Connecticut