Q & A WITH PAMELA SHERRATT

Is it worth applying seed as a dormant seed this winter , or should I wait

Great question ! Dormant seeding describes the process of applying seed to the field with the knowledge that it will not germinate / will stay dormant until environmental conditions are favorable for germination in spring . For cool-season grasses , that means applying seed during winter , knowing that it will not germinate until soil temperatures at 2 ” depth are consistently above 50 degrees F . While 50 degrees F soil temperature is the minimum , it ’ s worth noting that the optimum air temperature for coolseason grass germination is 60-80 degrees F .

In short , it ’ s absolutely worth it , particularly if you need to get a jump start on game preparation . Early spring sports often begin before the conditions are favorable for regular spring seedings . Getting the seed out in February and early March will offer many benefits : ( 1 ) the seed is already in place , ready to germinate when conditions are right ; ( 2 ) the seed is applied at a time that might not be as busy for the grounds crew ; ( 3 ) the germinating seed may have a competitive edge on emerging spring weeds ; ( 4 ) it might be easier to use seed-spreading equipment on fields before spring rains ; and ( 5 ) the germinating seeds will provide quicker ground cover than a conventional spring seeding .

Applying seed to bare soil or a thin sward is the goal . It is futile to apply seed – dormant or otherwise – to a full , dense sward of existing turfgrass . The existing , established sward cannot be switched out by applying a different seed type as a topdressing . Remember the golden rule of seeding success – there must be optimal seed-soil contact . During the freezing and thawing cycles in late winter , the soil structure changes due to the swelling and shrinkage of soil particles ; the volume of frost-susceptible soils increases ; and pores expand due to ice expansion during freezing . These soil pores offer a great opportunity for good seed-soil contact . Seed rates during dormant seeding are generally increased by 30 to 50 percent to account for higher seedling mortality and seed loss through wash-out , birds , etc . If the seed germinates and then a hard frost occurs , there might also be some seedling injury and / or death .

It ’ s important not to apply excessive seed amounts for the turf species . While “ more is better ” is tempting , particularly if there are spring deadlines to meet , the long-term success of the turfgrass plants relies upon having space and resources to fully develop and mature . In essence , larger plants have increased wear tolerance . Sod farmers will generally seed at , or just below , the recommended seed rate for a good reason . The turfgrass plants will not just grow , but will develop tillers , stolons and rhizomes that are critical during harvest . Those tillers , stolons and rhizomes are also critical for the long-term health of the plant and its ability to withstand athletic field traffic and wear . If seed rates are too high , the seedlings will be weak and susceptible to disease and other stresses .

To spread the seed , walk-behind spreaders / equipment that won ’ t cause soil damage and compaction are best , but if the soil is dry enough , heavier equipment can be used .

The only product applied during the winter dormant seeding operation should be the seed . Do not add a fertilizer product . In accordance with sound environmental stewardship , fertilizers should never be applied to snow-covered or frozen soils as there is a risk of runoff .

The types of seeds sown will depend on what the end goal is . If quick ground cover is the goal , faster-establishing species such as perennial ryegrass could be used . Tetraploid ryegrasses are an option worth investigating since they can germinate at lower temperatures than the standard perennial types .

A growth blanket is a great tool to aid germination and establishment – especially in high-traffic areas . Growth blankets keep the seed in place by minimizing wash-out ; retain moisture and heat , thereby accelerating the establishment rate and extending the growing season ; and keep birds and humans off . SFM

Pamela Sherratt Sports turf extension specialist The Ohio State University

Questions ? Send them to Pamela Sherratt at 202D Kottman Hall , 2001 Coffey Road , Columbus , OH 43210 or sherratt . 1 @ osu . edu

Or send your question to Dr . Grady Miller , North Carolina State University , Box 7620 , Raleigh , NC 27695-7620 , or grady _ miller @ ncsu . edu

50 SportsField Management | February 2023 sportsfieldmanagementonline . com