Going Natural on Pennsylvania Golf Courses
Cover Story
By Pete Landschoot, Ph.D., Professor of Turfgrass Science, Penn State University
The
trend of establishing infrequently mowed grass stands, often referred to as naturalized grass stands or native areas, on Pennsylvania golf courses has been steadily growing over the last two decades. Some reasons for this relate to aesthetics and design, whereas others center on reducing labor and conserving resources. At certain times of the growing season, the brown wispy seedheads of non-mowed grasses impart a natural look to the course, reminiscent of the classic links courses in coastal areas of the British Isles. Naturalized grass stands can also serve as hazards, offering challenges for golfers and penalties for errant shots (Figure 1). From the manager’s point of view, naturalized grass stands serve the practical purpose of reducing costs associated with water, fertilizer, fungicides and mowing. With budget reductions and labor shortages plaguing golf course operations across Pennsylvania and the U.S., it is no wonder that more areas are going “natural” on golf course properties. On the flip side, naturalized grass stands can be a headache for golf course managers. These areas often become infested with weeds, insects, and burrowing animals. Because of the nutrient-rich mineral soils throughout much of Pennsylvania, perennial grasses grow rapidly and stands can become extremely dense. Hence, mowing, thinning, and removal of stem and leaf debris may be needed to keep naturalized grass stands in good condition. Mowing and thinning operations often require specialized equipment, adding capital expenses to budgets of some golf course operations. The next few paragraphs provide a brief overview of the species, placement, mowing regimes, and weed problems of naturalized grass stands on Pennsylvania golf courses.
Species selection and establishment
In the Northeast and Mid-Atlantic regions of the U.S., the fine fescues and tall fescue are the most persistent and aesthetically acceptable grass species for naturalized areas on golf courses. Of the fine fescues, hard, sheep and Chewings are most popular in mixtures used for establishing naturalized stands. Although creeping red fescue performs well in most regions of Pennsylvania and is an excellent grass for weed suppression, it tends to become very dense and not conducive for finding or striking golf balls. Although creeping red fescue is present in some fine fescue mixtures, it is usually less than 40% by weight. By itself, creeping red fescue is best placed in areas furthest from active play. Hard and sheep fescues are relatively heat, drought, and shade tolerant when grown in non-mowed stands. Foliage of hard fescue is typically dark green, whereas sheep fescue foliage has a blue-green hue. Hard and sheep fescues are somewhat slower to establish than Chewings and creeping 6 Pennsylvania Turfgrass • Fall 2019
red fescue. However, they can make vigorous, and sometimes excessive, growth in fertile soils. Although hard fescue performs well in Southeastern Pennsylvania, trials in central Pennsylvania have shown occasional thinning and decline of some hard fescue cultivars in early spring following late fall mowing and cold winter temperatures (Figure 2). Chewings fescue cultivars have lighter green foliage than hard fescue and produce attractive light brown seedheads. This species grows well in most areas of Pennsylvania and is a common component of seed mixtures for naturalized grass stands (typically between 20 and 40% by weight). Mixing other grass species with fine fescues in naturalized grass stands is generally discouraged; however, one species native to North America, little bluestem, has performed quite well in our trials when mixed with fine fescue at low seeding rates. Tall fescue is less popular as a species for naturalized grass stands due to its coarse texture and the fact that golfers find it difficult to play from when dominant in non-mowed stands. However, it is persistent, heat and drought tolerant, and competitive with invasive weeds. This species also produces aesthetically pleasing seedheads when viewed from a distance (Figure 3). Although there are different ways of establishing fine fescues, we have had the most success when the entire site is treated with glyphosate, core aerated, and sliced prior to slit or broadcast seeding. Establishment from seed is generally more successful when performed in late summer versus spring, as there is less competition from weeds and the grass has two cool growing seasons to become established before being subjected to summer heat and drought stress. Seeding rates of fine fescues vary, but our research trials show that 4 lb./1000 sq. ft. provides a vigorous stand that is competitive with weeds. Starter fertilizer will help speed establishment, but once grass covers the soil surface, fertilization should be curtailed. Some golf course renovation projects have used fine fescue sod as a means of establishing naturalized grass areas. Although more expensive than seeding, this method offers the advantage of establishing fine fescue quickly with little to no weed competition.
Location
Location is a key consideration in using naturalized grass stands on golf courses. Non-mowed grasses located near irrigation heads will often lodge due to water accumulation on seedheads and become unsightly. Areas with tall grasses too close to fairways and greens are subject to lost balls and difficulty in striking the ball accurately, thus slowing play. Fine fescues are not particularly wear-tolerant and should be kept away from areas with high cart and foot traffic. To avoid these
