Researchers look into the helpful properties of fine fescue turgrasses

By Alec Kowalewski, Emily Braithwaite and Ruying Wang

Fine fescue is a group of different cool-season turfgrasses in the Festuca genus with narrow or fine leaves (Image 1). These grasses are generally known for excellent shade and cold tolerance, as well as persistence when maintained with minimal fertilization.

Considering these attributes, fine fescue is growing in popularity as homeowners and turfgrass managers seek more sustainable genus and species (Image 2).

Each of the five common fine fescues (strong creeping red fescue, slender creeping red fescue, Chewings fescue, sheep fescue and hard fescue) have a unique set of characteristics. For instance, strong creeping red fescue has a strong drought tolerance, germinates quickly and spreads quickly. This species is also the most common in seed mixtures.

Slender creeping red fescue tolerates lower mowing heights. Chewings fescue has the best shade tolerance. Sheep fescue can tolerate some of the lowest fertility conditions and persists with little or no irrigation.  Finally, hard fescue has excellent resistance to turfgrass pathogens such as red thread and dollar spot. 

Since 2012 the Oregon State University (OSU) Turfgrass Program has been part of a national and local fine fescue research initiative funded by the United States Department of Agriculture – Specialty Crops Research Initiative (USDA-SCRI), the National Turfgrass Evaluation Program (NTEP), the Northwest Turf Association, and the OSU Agricultural Research Foundation.

In this article we intend to share a few of the objectives and findings associated with this research initiative. These objectives include improving cool-season turf disease tolerance with symbiotic endophytes from hard fescue, evaluating fine fescue cultivars in Oregon, and determining the optimum seeding date and mulching material for fine fescue establishment in Oregon.

Improving turf stress tolerance

The inherent disease resistance associated with fine fescues is partially the results of Epichloë endophytes. Epichloë endophytes are symbiotic fungi that live within the turfgrass and help protect the host plant from various environmental stresses and pathogens. Previous research has identified Epichloë endophyte strains in hard fescue that provide resistance to dollar spot and red thread diseases.

Research at OSU is currently exploring the transference of this symbiotic organism from hard fescue to other fine fescue species and subspecies, as well as other cool-season grasses like perennial ryegrass and tall fescue to improve the disease resistance and stress tolerance (Image 3).

Evaluating fine fescue cultivars

From 2014 to 2019 the OSU Lewis-Brown Horticulture Farm in Corvallis was a fine fescue testing location for the National Turfgrass Evaluation Program (NTEP). For detailed data such as spring green up, percent green cover, monthly turfgrass quality, red thread tolerance and traffic tolerance of 42 cultivars of the five fine fescues in Oregon and other location visit the “NTEP 2014 National Fineleaf Fescue Test: 2015-19 Data” (https://tinyurl.com/cprmzxpc).  

In 2020, a new 5-year fine fescue NTEP study with 43 entries was initiated at the the Lewis-Brown Horticulture Farm in Corvallis.

Optimum seed date

Part of the multi-state USDA-SCRI fine fescue initiative was to identify ways that people can incorporate these low-input grasses into existing landscapes. We know that the fine fescue species persist in shade, with low water requirements, and low fertility requirements, but overcoming the social barrier for adopting more sites with these grasses was a primary focus of this initiative. In order to recommend this as a species for homeowners and turfgrass managers, it’s important to identify the best time of year to plant and establish the grass.

OSU, along with three other universities across North America, initiated an optimal seeding date trial for fine fescues to identify which month of the year was best to seed fine fescues in different regions across the US. Nine monthly fine fescue seeding timings from March through November were investigated with a seed mixture of strong creeping red, Chewings, hard, and slender creeping red fescue (Image 5). 

Prior to seeding, plots were sprayed with glyphosate to eradicate any weeds. The fine fescue mixture was then seeded into these plots at one of the nine predetermined seeding dates, along with a starter fertilizer. Following seeding, plots were irrigated frequently to promote establishment. No additional fertilizers or pesticides were applied to plots following seeding.

Data collection consisted of monitoring weather data, observing the number of days until emergence, visual turfgrass cover and quality, and grid intersect counts to assess the percentage of weeds and fine fescue in each plot. 

Results from across all four locations showed that as temperatures increased during the growing season, the time required for fine fescue emergence decreased.  Seeding in August and September, however, produced the best establishment with the lowest weed pressure.

Oregon has much more of a Mediterranean climate compared to the other locations of this study, and as such that allowed for more flexibility in seeding timing.  Overall, Oregon had a much wider seeding window of May through September.  All those plots were successful at establishing, and many had low weed encroachment.

Spring seeding in Oregon with fine fescues can be successful, and is a good option for homeowners and turf managers. One consideration, however, is that due to the drier spring/summer climate in our region, irrigation is a critical requirement to get good establishment of fine fescue. Seeding timings in September may still require frequent irrigation for emergence, but more rain events from September through May will reduce the overall need for irrigation for fine fescues seeded in the fall. 

Optimum mulching material

When we get into springtime, and the weather starts warming up, it’s not uncommon for homeowners to begin using commercial “patch and repair” products on their lawns to seed bare or damaged areas from the previous seasons. These products contain about 85 to 90% inert matter (i.e. wood or paper based mulch) to help retain moisture, and the other 10 to 15% is fertilizer and grass seed.

Typically, these “patch and repair” products are comprised of other grass species (tall fescue and perennial ryegrass), and very few of them are fine fescues. The overall cost per pound (lb) of seed in these pre-made mixes is very high, so we decided to test materials available to homeowners or turf managers from nurseries or garden supply stores that they could use to make their own seed mixes. We included newspaper, top soil, compressed paper mulch, compost, woodchips, potting soil, and no mulch material (Image 6, right).

All treatments included a 95% (by volume) mulch ingredient, 0 or 1% starter fertilizer, and 5% fine fescue seed mix (strong creeping red fescue, Chewings fescue, hard fescue, and slender creeping red fescue). The ingredients were mixed by hand in a 5-gallon bucket and hand seeded onto 2’ x 2’ plots in April 2019 (Image 7, bottom right). Once treatments had been seeded, the area received daily irrigation to promote establishment. Data collection included number of days required for seedling emergence, establishment rate, visual quality, and percent weed encroachment at the trial’s conclusion.

Conclusion

Mulch ingredient had a significant impact on seed emergence and establishment. The woodchips, newspaper shreddings, and pressed paper mulch inhibited establishment early on.  Although eventually they filled out with fine fescue, we don’t recommend using those materials in a patch and repair mix.

Using potting soil or compost provided for the quickest emergence of fine fescues in this trial. This could be due to those materials holding moisture better, and providing warmth and cover to the seed which sped up germination. The compost in particular required the fewest number of days to reach 50, 75, and 90% establishment. 

We found that if a site is adequately irrigated, mulch materials and fertilizer might not be necessary to include for repairing areas, but to speed up the process, including compost or potting soil was beneficial. Overall, major cost savings can be made by making your own mulch mixes. The average cost for pre-made “patch and repair” products is about $2.79 per pound, but mixing your own can bring that cost down to about $0.45 per pound (Braun et al., 2020).

Acknowledgments
National Institute of Food and Agriculture,
  Grant/Award Number: 2017-511812017- 27222
National Turfgrass Evaluation Program
Northwest Turf Association
Oregon State University Agricultural
  Research Foundation

Reference:
Braun, R.C.,  A.J. Patton,  E.T. Braithwaite  and A.R. Kowalewski. 2020. Establishment of low-input turfgrass from seed with patch and repair mixtures: Mulch and starter fertilizer effects. 17 July 2020 https://doi.org/10.1002/csc2.20266