Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension
www.extension.umn.edu
612-624-1222

Extension > Garden > Lawns and turfgrass management > Repair > Renovating a lawn for quality and sustainability

Print Icon Email Icon Share Icon

Renovating a lawn for quality and sustainability

Sam Bauer and Jonah Reyes

In addition to introducing different types of grass into a lawn, renovation may be considered when lawn quality has become unacceptable.

Consider renovation when:

  • Introducing lower maintenance turf varieties into an existing lawn (usually through overseeding).
  • Approximately 30 to 50 percent of the lawn is dead or has very sparse growth. This may be due to a variety of factors such as low soil fertility, drought and heat, insect damage, poor mowing practices, disease, moderate soil compaction, or increasing shade and competition from growing trees.
  • The lawn is soft and spongy when walking across it and responds poorly to regular watering and fertilizer applications. This condition usually indicates excessive thatch (greater than 3/4 inch).
  • Broadleaved weeds (such as dandelion, plantain, and knotweed), or grassy weeds (such as crabgrass) cover about 30 to 50 percent of the lawn area and there is insufficient existing turf cover to fill in the bare areas once the weeds are removed.

Determine the reasons for the lawn declining before renovating the area. Many times making modifications in basic lawn care practices, cultural practices or site conditions can bring a lawn back to good health and vigor such that renovation is not necessary.

Basic steps for lawn renovation

The preferred time for lawn over seeding/renovation is from mid-August to mid-September. The second best time is usually early spring just as the lawn is beginning to turn green and grow.

Follow these renovation steps to achieve a healthy, sustainable lawn:

1. Conduct a soil test

2. Begin weed control

  • Use broadleaf herbicides if the weeds are primarily non-grasses.
  • Non-selective herbicide will kill most green vegetation. This herbicide requires 5-14 days for proper function.

3. Provide adequate soil moisture

  • Wet soil to a depth of 6-8 inches; then allow the surface to dry until steps 4 and beyond can be done - may require 1-2 days.
  • Do this step when necessary; this will usually be during the summer months.

4. Mow

  • Mow existing lawn very short; even to the point of scalping it. This will allow good sunlight levels to reach the soil and encourage faster establishment of new seedings.
  • If you are only intending to remove excess thatch, then the grass does not have to be cut as short as when you are overseeding.

4. Remove thatch

  • Vigorous hand raking is not practical for an extreme thatch problem or for large areas.
  • Professional lawn care services provide vertical mowing services for thatch removal. Vertical mowers can also be rented. This method can also be used to prepare the seedbed
  • For extreme thatch problems sod should be removed. Sod cutters are an effective removal tool. These services are also available from lawn care professionals, and are available for rent.

5. Prepare soil

  • Vigorous hand raking is effective for small patches of grass with little vegetation remaining.
  • Three to five passes with a commercial aerifier is recommended if the soil is compacted.
  • Vertical mowing is another option; the times should nick the soil surface to a depth of 1/8 to 1/2 inch. Two to three passes are necessary. Vertical mowers are available with a seeder attached. See seed splitting in step 8.

6. Fertilize

  • A combination of Nitrogen (N), Phosphorous (P), and Potassium (K) are required for fertilization.
  • Apply additional P and K as determined by a soil test.
  • Avoid adding additional N as it will over-stimulate the existing grass thereby crowding out the new seedlings.
  • For post-seeding fertilization fertilize with 1/2 pound of actual N per 1000 square feet. Use a slow release N source after the first mowing

7. Seed

  • Find the recommended seed mix for your lawn below.
  • Divide the seed lot into halves or quarters and seed in two or four directions
  • Hand seeding can be used for patches or small areas (less than 8 feet across). Mix 1 part seed with 4 parts of a natural organic fertilizer; this is termed "bulking-up" and makes small amounts of seed easier to distribute uniformly.
  • Rotary spreading is an acceptable method when the seed is bulked-up. Seed in two directions.
  • Drop spreaders are useful when the seed is used alone or bulked up. Seed in two directions or overlap 1/2 of previous row of grass.
  • Slit seeding equipment can be rented, but requires skill to operate correctly. Generally this should be done by a professional. The slit seeder will go over the site in two directions using half of the seeding rate in each direction.

8. Irrigate

  • Roll lightly to provide good seed to soil contact; then, water lightly and often enough to keep the soil surface slightly damp.
  • Do not allow soil to become too dry or too wet.
  • Continue to keep the area moist until all varieties have germinated. Remember, Kentucky bluegrass can take 2 to 3 weeks to germinate.

9. Mow again

  • Initially maintain the shorter height of cut on the existing lawn to insure that enough sunlight will continue to reach the new seedlings.
  • As the new seedlings develop and attain the same height as the existing grasses, the overall height of cut can be raised to the desired level.
  • Continue these shorter heights of cut for about 1 month or until the slowest germinating seeds are up and growing.

Lawn categories and recommended seed mixes

Category 1: minimum input, sunny location

Grass that requires low input and grow well in sunny locations:

  • Generally aren't watered
  • Fertilize once a year or less
  • Mow no more than once a week
  • More drought-tolerance is desired

Recommended seed mix

Mixture of 50 to 60% common type Kentucky bluegrasses and 40 to 50% fine fescue.

Include at least two varieties from Aquila, Monopoly, Nassau, Newport, Nugget, Park, Ram I, Rugby, South Dakota Certified, Sydsport, Touchdown, or other common Kentucky bluegrass.

One or two varieties of fine fescue (sometimes listed on the seed label as creeping red fescue, Chewings fescue, or hard fescue) should also be included.

Turf-type tall fescues may also be used if traffic and drought tolerance are desired.

Category 2: Minimum input, partially shady location

Grass that requires little input and grows best in a partially shady location:

  • Generally won’t be watered
  • Fertilize once a year or less
  • Mow no more than once a week
  • More drought-tolerance is desired

Recommended seed mix

Seed with mixture of about 80-100% fine fescue grasses and 20%Kentucky bluegrass.. Turf-type tall fescues may also be included. For heavily shaded areas, rough bluegrass (Poa trivialis) or supina bluegrass may be used, however care should be taken to not transfer these species to full sun situations.

Category 3: moderate to high input, sunny location

Lawns that require moderate to high input and grow best in a sunny location:

  • Water well throughout season
  • Fertilize 2-4 applications of ¾ to 1 pound of nitrogen for every 1000ft2 of lawn
  • Mowed properly according to how fast the lawn grows, remove no more than 1/3 of leaf tissue when mowing

Recommended seed mix

Seed with a blend of improved Kentucky bluegrass varieties or a Kentucky bluegrass/perennial ryegrass (turf-type) mixture. Many named varieties not listed under Category 1 are improved Kentucky bluegrass varieties and will perform best under higher input conditions. A fine fescue species may also be included.

Category 4: Low to moderate input, shady location

Grass that requires low to moderate input and grows best in a shady location:

  • Generally won’t be watered
  • Fertilize once a year or less
  • Mow no more than once a week
  • More drought-tolerance is desired

Recommended seed mix

Seed with a blend of fine fescue species such as Chewings, creeping red, hard and sheep. Many commercial shade mixes may also include tall fescue, rough bluegrass (Poa trivialis) and perennial ryegrass. Select mixtures that are void of perennial ryegrass as this species does not tolerate shade. When selecting fine fescue varieties try to avoid older, non-improved selections such as ‘Boreal’ Strong creeping red fescue.

2017


  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy