University of Maryland Extension

Lawn Renovation and Overseeding

closeup of lawn

Key Points:

Why do lawns fail?

  • Weed infestation. Reseed bare areas otherwise, weeds such as crabgrass will invade.
  • Drought. Lawns often recover after a drought when rainfall returns but not all the time. 
  • Too much shade and competition from tree roots. Consider lawn alternatives for shady areas and mulch rings around trees.
  • Heavy foot traffic. Heavily used lawns should be core aerated to relieve compaction and overseeded if necessary.
  • Poor drainage. Grass needs well-drained soil to grow well.
  • Incorrect mowing practices. Scalping the lawn and mowing too often stresses out the grass and sometimes kills the crown (where new growth is generated) resulting in thinning grass. 
  • Too much or too little fertilization causes problems. Fertilize according to the University of Maryland Extension lawn fertilizer schedule

Complete Renovation

An 'overhaul' of a lawn is a lot of work but should be considered if your lawn is over 50% weeds. Another option to consider is a lawn alternative especially for the most problematic areas of your yard. 

Renovation steps

  1. Send in soil samples for soil testing.
  2. Decide on seed or sod.
  3. Begin to kill the existing vegetation in June/July if using physical methods like smothering. Physical methods work well on small spaces less than 100 square feet. Refer to Lawn (Turfgrass) Removal Methods for more information. For larger areas, renting a sod cutter is an option. A sod cutter slices under the roots and lifts strips of the sod from the ground exposing the bare soil.
    You can kill vegetation before planting using a non-selective herbicide that contains glyphosate. If you choose this method do not mow the area to be sprayed a few days prior to or after the application of the herbicide. Controlling tough perennial grass weeds (bermudagrass and quackgrass) can take as long as a month to achieve. Two or three applications of the herbicide throughout the month may be necessary if there is regrowth after the initial application. Plan to begin the process in early to mid-August. This will allow ample time for reseeding. Proceed to the next step when the weeds have turned brown and no new growth has occurred.
  4. Prepare the site for planting. Set your lawnmower on the lowest setting and then mow. Rototill the dead plant material to create the seedbed. Or you can rent a vertical mower or power rake (more information below) to prepare the site. Make at least two passes over the area. If a thatch layer exists use a vertical mower or, in extreme cases, rent a sod cutter. Add lime and fertilizer according to soil test results and till or rake into the soil. Apply and rake in a 1-2 inch layer of compost if the soil organic matter is less than 3% according to soil test results. Rake the area to even and smooth it out or lightly roll with a water-filled roller.
  5. Sow the grass seed or lay the sod. Divide the seed into two parts; apply one-half in one direction (north/south) and the remainder in the opposite direction (east/west). Sow seed with a lawn spreader. Water immediately after installation and begin lawn care practices. 
    Lawn  renovation seeding rate
    Turf-type tall fescue6-8 lbs. per 1,000 sq. ft.
    Kentucky bluegrass2-3 lbs. per 1,000 sq. ft.
    Fine fescue4-5 lbs. per 1,000 sq. ft.

Overseeding

Helps to improve the overall quality of your lawn. Overseeding thickens up grass to help prevent weeds and repairs damaged areas. A marginal lawn can be improved by overseeding and following our lawn care advice on fertilizing, mowing, soil testing, etc.

Overseeding steps

  1. Test soil
  2. Purchase grass seed
    Overseeding  rates  
    Turf-type tall fescue4 lbs. per 1,000 sq. ft.
    Kentucky bluegrass1.5 lbs. per 1,000 sq. ft.
    Fine fescues2.5 lbs. per l,000 sq ft.
  3. Set your mower on the lowest setting and mow the lawn.
  4. Rake to remove clippings and to loosen up the soil. Rent a core aerator, vertical mower, or slit seeder for larger areas (see lawn renovation equipment below).
  5. Sow the seed. Divide the seed into two parts; apply one-half in one direction (north/south) and the remainder in the opposite direction (east/west). Sow seed with a lawn spreader for even distribution.  
  6. Good seed-to-soil contact is necessary for germination. Tamp the seed down with the back of a metal rake or for larger areas use a water-filled roller to firm the seeds into the soil.
  7. Care and maintenance after seeding (Need to create page).

Lawn Renovation Equipment

core aerator machine
Core aerator

Power RakeUsed for thatch removal. This is a lawnmower type machine with tines instead of blades that rip the thatch out of the ground. Hand raking is then needed to remove the debris.
Vertical mowerAlso called a verticutter. Similar to a power rake but cuts down through the thatch into the soil. Renting a verticutter is better than a power rake if you are planning to overseed after thatch removal. It cuts deeper into the soil and therefore provides better seed-to-soil contact. Rake up the debris before sowing the seed.
Slit seederThis machine makes small grooves in the soil, then deposits the seed into the slit. Apply half of the seed in one direction and the other half on a second pass, perpendicular to the first. When renting a slit seeder, check to be sure it deposits the seed after it makes the groove and not before.
Core aeratorCore aeration is a means of alleviating compacted soil. Aeration opens the soil up to allow air, water, and fertilizer to penetrate and roots to grow. Look for an aerator that pulls plugs of soil out and distributes them on the surface, instead of one that just punches holes in the ground. Plugs should be 2 – 3 inches long and about ½ inch in diameter. Plugs can be left on the lawn. Aeration should be done on moist soil only. Avoid soil extremes (either too dry or too wet.) 
Waterfilled rollerUsed to smooth the planting site and to firm the seed into the soil after sowing. Also used to lightly roll sod after installation.
Sod cutterA machine, either manual or powered, to remove turf. Turf is removed in strips exposing the bare soil. Used before complete lawn renovation.

Repairing bare spots

Reseed dead patches of grass or bare spots to keep your lawn uniform looking and to help keep weeds out. Purchase the same type of grass seed as your existing lawn. For example, use tall fescue seed without any other grass species, like perennial rye, if that is what you have.
Rake up the dead grass and loosen up at least the top inch of soil. Compost can be worked into the soil. Sprinkle the seed over the area, being careful not to seed too heavily. Tamp the area down with the back of a steel rake and mulch lightly with straw. Water with a fine mist spray. Keep the area moist until the grass becomes established.

Video

Additional Resources

By Debra Ricigliano, Maryland Certified Professional Horticulturist, University of Maryland Extension Home and Garden Information Center (HGIC), 2019. Reviewed and edited by Jon Traunfeld, HGIC Director and Christa Carignan, HGIC Coordinator, Digital Horticulture Education.
Based on HGIC publication HG 102 Lawn Establishment, Renovation, and Overseeding.

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