Solving Those Overseeding Blues

Leah A. Brilman, Ph. D. Research Director Seed Research of Oregon www Leah A. Brilman, Ph.D. Research Director Seed Research of Oregon www.sroseed.com

Thanks! Eric Case - Marriot’s Camelback Golf Resort, Scottsdale, AZ Shawn Emerson, Joe Tropico, Chris Montague - Desert Mountain Golf Properties, Carefree, AZ Paul Elwood - The Gallery, Marana, AZ Jim Moore - TPC Eagle Trace, Coral Springs, FL Fred Klauk - TPC Sawgrass, Ponte Vedra, FL Cal Roth - TPC Dr. Bruce Martin - Clemson University, SC Dr. Larry Stowell - PACE Kelly Schuck - ProSource One, Glendale, AZ

Why overseed ? Provide green color during winter = more play and more revenue Increase wear tolerance during dormant season Improved playing surface during winter

What to overseed ? Dependent on location, budget, and course design Greens - Most courses Fairways - Many courses Roughs - Some courses Species selection also depends on location, budget, and course design

Why overseed with different species? Use mixtures for genetic diversity Resistance to diseases and stresses Color contrast Improved transition Improved quality Smaller seeds Potential cost savings

Why overseed with different species? Resistance to diseases and stresses Chytridiomycete on Poa trivialis in SC

Why overseed with different species? Color contrast

Species for Overseeding Ryegrasses Perennial, intermediate, annual Fine fescues Chewings, slender creeping red, strong creeping red, hard Bentgrasses Velvet, colonial, creeping, dryland, Idaho Bluegrasses Rough bluegrass, Kentucky, others Other species

Perennial Ryegrass Assets Standard High quality - tops many tests Rapid germination Quick establishment Very dark green color Known cultural conditions Good Poa control

Perennial Ryegrass Problems Poor transition, heat tolerance high Susceptible to Chytridiomycete fungus Wider leaf blade Larger seed size - more difficult to establish in ultradwarfs Soil surface disruption & damage for establishment Most expensive per square foot

Intermediate Ryegrass New improved varieties for turf Quality significantly better than annuals or older intermediates Medium green Quality approaching older turf-type perennials Quicker transition than perennials Less expensive than perennials Can be included in mixtures

Fine fescues Chewings, slender creeping red, Strong creeping red, hard Very fine with stiff texture Good wear tolerance Winter-active growth Improved transition with high quality Rapid germination - Chewings and red Resistance to Chytridiomycete fungus Medium seed size

Fine fescues High salt tolerance Color and texture contrast Increase genetic diversity of mixtures Mixtures with perennial ryegrass, bentgrasses, Poa trivialis Seeding rates (alone) - Do not mow too soon Greens 25 - 30 lbs./1000 sq. ft. Tees 20-25 lbs./1000 sq. ft. Fairways 10-15 lbs./1000 sq.ft. - Excellent

Dawson slender Perennial ryegrass Creeping red fescue

Velvet Bentgrass Very small seed size (best for ultradwarfs) Best putting surface Highest wear tolerance, high density Medium establishment Germinates well at low soil temperatures Medium dark green Best shade tolerance Excellent transition

Velvet Bentgrass Creeping bentgrass SR 7200 Velvet bentgrass

Colonial bentgrass Highland Colonial ‘Highland’ bentgrass is a dryland bentgrass not a colonial bentgrass Highland Colonial A. castellana A. capillaris blue-green true green stolons stolons long rhizomes usually no rhizomes scalp/false crown more upright

Colonial bentgrass Small seed (good for ultra-dwarf bermudas) Medium establishment Medium dark green High wear tolerance Good transition High turf quality High density Less expensive

Creeping bentgrass Small seed (good for ultradwarfs) High putting quality High salt tolerance Moderate transition - cultivar dependent Can persist into early summer Medium to slow establishment Dark to medium blue green color Excellent if have heavy play in early summer

Other bentgrass Dryland “Highland” bentgrass, Idaho bentgrass, Redtop Small seed (good for ultradwarfs) Quality not as high Moderate transition Variable establishment Dark to medium gray green color

Rough bluegrass Smaller seed size (ultradwarfs & zoysias) Medium to fast establishment rate Stoloniferous (can become weed) Transition - poor to good Fine texture Light to medium green High density Very susceptible to Chytridiomycete Blend of cultivars or lots improves establishment

Kentucky bluegrass Smaller seed size (ultradwarfs & zoysias) Slow establishment rate, best if need spring or early summer performance Stoloniferous / rhizomatous Transition - poor to good Fine to medium texture Dark green color High density Excellent cold tolerance and retain their green color under freezing temperatures

Species Mixtures Combines strengths/weaknesses Less likely to have diseases Adjust initial management/mowing to insure multiple species establish Smoothes out transition, more staged Can reduce costs

Species Mixtures Successful mixtures Perennial ryegrass + rough bluegrass Above + bentgrass (velvet, creeping, colonial) Colonial bentgrass + Chewings or red fescue Velvet bentgrass + Chewings or red fescue Rough bluegrass + bentgrass Perennial ryegrass + fine fescues Above + bentgrasses Slender creeping red + creeping bent - salt or Chrytridiomycete sites

Other species Hairgrasses - Deschampsia ssp. Dark to light green Transitions well Very wear tolerant Junegrasses - Koeleria ssp. Seeding rates? Good color, wear tolerance

Improving transition Bermudagrass preparation Control thatch during summer - frequent light verticutting, topdressing Heavy verticutting damages stolons and rhizomes needed for recovery Spring Management Lower mowing height - scalping on roughs Increased nitrogen Light verticutting if hot - check bermuda Aerification and topdressing

Future Work Collect and evaluate more species Regionalize species recommendations New species need management/chemical work Work with Universities/ Plant Material Centers Economic seed production Market development