Overseed Trials 1996-1997

A.E. Dudeck and S.F. Anderson
University of Florida, Gainesville
Institute of Food and Agricultural Sciences

As bermudagrass sports turfs and playing surfaces in southern United States go dormant in winter, the practice of overseeding with unadapted cool-season grasses provides live green turf cover and improves playing surfaces. Seed producers and turfgrass breeders continue to develop new cultivars providing numerous new cool-season grasses for overseeding. In addition to new cultivars, producers also formulate new grass mixtures and blends. Timely trials are needed to evaluate performance and provide information to potential consumers of these grasses. The purpose of these annual studies was to evaluate suitability of selected cool-season turfgrass species, cultivars, mixtures, and blends for overseeding purposes in north Florida.

Thirty-seven cool-season grasses were overseeded in a 'Tifway' bermudagrass fairway on 25 October 1996. They were also seeded in a 'Tifdwarf' bermudagrass putting green on 27 October 1997. Both studies were conducted at the G.C. Horn Turfgrass Field Laboratory, Gainesville, FL. Grasses along with their composition and seed source are listed in Table 1. Normal establishment and maintenance practices were followed in both studies.

Perennial ryegrass was seeded at a rate of 15 pure live seed (PLS) per square inch in the fairway study and at a rate of 50 PLS per square inch in the putting green study. Because of differences in seed size, purity, and germination, bulk seeding rates of perennial ryegrass varied from 7.3 to 11.2 pounds of seed per 1000 square feet in the fairway study and from 24.4 to 37.4 pounds per 1000 square feet in the putting green study. Similarly, bulk seeding rates of rough bluegrass varied from 1.4 to 2.9 pounds per 1000 square feet in the fairway study and from 4.8 to 9.6 pounds per 1000 square feet in the putting green study. Because bulk seeding rates varied as much as two times to obtain the same seeding rate based on PLS, grass seeding rates should always be based on PLS content rather than bulk seed weight.

Cool-season grasses had difficulty in establishing due to serious competition from bermudagrass. Above normal temperatures during two weeks following seeding were recorded. Under optimum conditions, perennial ryegrass normally establishes within five to seven days following seeding. Because of bermudagrass competition, 'Plaisir' perennial ryegrass, which had highest rate of establishment of all grasses, required 85ñ44 days to produce 50% ground cover. This was due to a 40% loss of perennial ryegrass during the third week after seeding.

Best grasses with least weeds and disease incidence in the 7-month putting green study were summarized as follows:

Parameter Overseeded grass
Establishment rate 'Plaisir' perennial ryegrass
Mixture of 'Citation III' perennial ryegrass with 'Winterplay' rough bluegrass
Turf quality BARUSA Pt4 rough bluegrass
Mixture of 'Citation III' perennial ryegrass with 'Winterplay' rough bluegrass
Mixture of 'Sabre II' rough bluegrass with 'AT 90163' colonial bentgrass
Dark green color 'LRFB7' perennial ryegrass
'MB45' perennial ryegrass


Best grasses with least weeds and disease incidence in the 7-month fairway study were summarized as follows:

Parameter Overseeded grass
Establishment rate 'Plaisir' perennial ryegrass
Turf quality 'Academy' perennial ryegrass
Blend of 'Imagine', 'Lynx,' and 'Pegasus' perennial ryegrass
'Gator II' perennial ryegrass
'HWY' perennial ryegrass
'LRFB7' perennial ryegrass
'MB45' perennial ryegrass
Mixture of 'Citation III' perennial ryegrass and 'Winterplay' rough bluegrass
'Plaisir' perennial ryegrass
'Premier II perennial ryegrass
'Resort' perennial ryegrass
Dark green color Blend of 'ICE', 'ET', and 'PI' perennial ryegrass
'Imagine' perennial ryegrass
'LRFB7' perennial ryegrass
'MB45' perennial ryegrass
'Premier II' perennial ryegrass
'Roadrunner' perennial ryegrass


High temperatures following seeding along with abnormally high air temperatures in February and March of 1997, which averaged 4.8øF above normal, contributed to the atypical results of these overseed studies. Unfortunately, no one can control or accurately predict seasonal growing conditions. Thus, overseed trials must continue on an annual basis to document plant response under optimum as well as suboptimum growing conditions.

Table 1. Cool-season turfgrasses with their composition and seed source that were overseeded during the 1996-1997 winter period at Gainesville, FL.

Components Entry Mix/Blend Cultivar Speciesz Source (%) Academy 100 Academy PR Pratum Co-op Warehouse Barcrown 100 Barcrown RF Barenbrug HOLLAND BARUSA Pt4 100 BARUSA Pt4 RB Barenbrug USA Blend 1 33 Imagine PR Olsen-Fennell Seeds, Inc 33 Lynx PR 33 Pegasus PR Blend 2 33 ICE PR Olsen-Fennell Seeds, Inc 33 ET PR 33 PI PR Catalina 100 Catalina PR Pure Seed Testing Charger II 100 Charger II PR Pure Seed Testing Danish Common 100 Common RB Pickseed West, Inc. Eagle Blend 33 Assure PR Lesco 33 Commander PR 33 Williamsburg PR Fuzzy 100 Fuzzy RB Olsen-Fennell Seeds, Inc. Gator II 100 Gator II PR International Seeds GK 3way Blend 33 Brightstar PR Pure Seed Testing 33 Charger PR 33 Sunrye PR HWY 100 HWY PR Olsen-Fennell Seeds, Inc. Imagine 100 Imagine PR Olsen-Fennell Seeds, Inc. Juwel 100 Juwel PR Duetsche Saatveredelung Lipoa 100 Lipoa KB Deutsche Saatveredelung Livonne 100 Livonne PR Deutsche Saatveredelung LRFB7 100 LRFB7 PR Lofts Seed MB45 100 MB 45 PR Scotts Company Mix 1 20 Winterplay RB Pure Seed Testing 80 Citation III PR Mix 2 40 AT 90163 AT International Seed 60 Sabre II RB Pageant 100 Pageant PR Pratum Co-op Warehouse Pearl 100 Pearl PR Pratum Co-op Warehouse Penn A-4 100 Penn A-4 CB Tee-2-Green Penn G-2 100 Penn G-2 CB Tee-2-Green Penn G-6 100 Penn G-6 CB Tee-2-Green Plaisir 100 Plaisir PR Deutsche Saatveredelung Premier II 100 Premier II PR Barenbrug USA Pt A 100 Pt A RB Barenbrug HOLLAND PT B-93 100 PT B-93 RB Pickseed West, Inc. PT I-93 100 PT I-93 RB Pickseed West, Inc. Resort 100 Resort PR Lesco Roadrunner 100 Roadrunner PR Pure Seed Testing Southshore 100 Southshore CB Sunbelt Seed Top Hat 100 Top Hat PR International Seed TTAR 100 TTAR PR Olsen-Fennell Seeds, Inc Winterplay 100 Winterplay RB Pure Seed Testing zAT=Colonial bentgrass, Agrostis tenuis, CB= Creeping Bentgrass, Agrostis palustris, RF= Red fescue, Festuca rubra trichofylia, KB= Kentucky Bluegrass, Poa pratensis, RB=Rough Bluegrass, Poa trivialis, PR Perennial ryegrass, Lolium perenne.