Overseeding

TRF 230

Why Overseed

• Bermuda goes dormant

• Green color

• Traffic tolerance

• Economic reasons

Overseeding Myths

• Drainage improves

• Protects from winter kill

• No effect on Spring Transition

• Reduces weed populations

Factors Influencing a Good Overseeding

• Timing

• Seedbed Preparation

• Grass Selection

• Seed Quality

• Seeding Rate

Timing

• Too early: disease and bermuda competition

• Too late: Poor germination rates due to low temps

• Night temps in the 50’s• Soil temps at 4 inch depth low 70’s• Cool season turf favored by temps

between 50 and 70 degrees• 20-30 days before first killing frost

Seed Bed Preparation

• Year long process

• Purchasing seed and seed selection

• Over seeding schedule

• Healthy bermuda grass base

Seed Bed PreparationGreens and Tees

Three to six weeks before overseeding • Nitrogen fertilization reduced or stopped to

reduce bermuda competition • Soil cultivation be sure to allow time for

recovery• Vertical mowing to reduce thatch and open

soil surface• Topdressing• Apply P and K (get a soil test)

Seed Bed PreparationGreens and Tees

Ten to 14 days

• Reduce mowing height

• Light vertical mowing to enhance seed moving through canopy

• Clean debris

• Irrigate good

Seed Bed PreparationFairways

• Less intensive

• Close mowing

• Remove debris

• Correct thatch problems if they are a problem

Grass Selection

• Perennial Rye grass larger seed• Poa trivialis smaller seed• Blends different cultivars of same speciecs• Mixtures different cultivars of different species• Budget• Intended quality• Planting date• Traffic or play intensity

Grass Selection

Select a blend or mixture to customize your overseeding to meet your requirements

• Green color, texture, density• Establishment rate, winter and spring

performance• Spring transition, wear and shade tolerance • Putting quality, competitiveness with Poa annua• Disease resistance

Seed Quality

• Blue Tag Certified Seed

• Percent purity

• Free of hard to control weed seeds

• Acceptable germination rates

• Fungicide treated seed

Seeding Rate

Depends on seed size, area and use

• Too low thin stand of grass and large plants

• Too high weak stand that is disease prone

• Perennial Ryegrass 25-40 Lbs per M for greens 250-450 Lbs per acre

• Poa trivialis 8-12 Lbs per M for greens

Overseeding ProcessGreens

• Varies by superintendent and situation• Apply seed when surface is dry• Wind speed less than 5 mph• Carefully calibrated spreaders 2 different

directions• Protect boundaries• Light topdressing• Drag seed in with carpet

Overseeding ProcessFairways

• Seed in two different directions

• Mat or drag in seed

Post Planting Care

• Light and shallow irrigation careful not to puddle water

• Brush seed back in place that gets moved by water

• Reduce irrigation as grass gets established

Post Planting Care

Disease Management

• Pythium and Brown patch

• Apply fungicide 5-7 days after planting

These diseases are favored by:

• Warm weather

• Long periods of moisture on the leaf

• High seeding rates

Post Planting Care

Mowing

• Start out at ½ inch and gradually lower by 1/32 to ¼ inch in 2 to 3 weeks

• 4-6 weeks until reach 3/16

• Use sharp mower

Post Planting Care

• No Nitrogen until bermuda has stopped growing

• 2 to 3 weeks after seedlings have emerged

• ¼ to ½ Lbs of Nitrogen every 2 to 3 weeks

• Minimize traffic

For winter management proper fertilization and irrigation ½ lbs of N every 2-3 weeks