Lawn and Garden

Lawn Renovation

Lawn + Garden Projects

Lawn Renovation

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If your lawn is a teenager—say 15 years old, or so—it might be time to give the yard a fresh start by renovating it. Over time, thatch buildup can choke out healthy grass and promote weeds and disease. Thatch is a layer of partially decomposed grass stems, roots, and rhizomes at the soil surface. An indication of too much thatch is a spongy, soft lawn that doesn’t take well to watering and fertilizers.

Other symptoms of a lawn that needs renovation include dead spots or areas of sparse growth, which can be due to infertile soil, drought, insect damage, poor mowing practices, disease, soil compaction, or too much shade. Generally speaking, if 20% - 40% of your lawn is dead or dying, you can remedy the problem through lawn renovation. If more than 40% of your lawn is in dire condition, you will need to reseed or re-sod your lawn.

Thatch hides below the grass surface, so you may need to cut out a 6"-deep wedge so you can measure the level of thatch. If you can see that the thatch is deeper than 1/2", then you’ve got some lawn renovation to do.

First, Diagnose the Problem

Before you begin the lawn renovation process, determine why your lawn is failing. Once you identify the cause, you can take corrective action during the renovation process and start fresh with proper cultural practices such as mowing, fertilizing, and watering as soon as the process is complete. Careful observation and taking soil samples for analysis can shed light on what’s ailing your lawn.

Some of the diagnostic questions you’ll need to ask are: How thick is the thatch? How much of your lawn is overtaken with weeds? What weather conditions (heat, drought, excessive moisture) might have contributed to the lawn’s condition? The fix might be as simple as trimming back a tree canopy that’s preventing a patch of your lawn from receiving adequate sunlight. Usually, the problem stems from a variety of issues: thatch and an insect problem, plus a dry summer—you get the idea.

A soil test is the best way to get to the root of a lawn problem. By collecting soil samples and testing the soil pH level, which is its acidity and alkalinity, you’ll have the information you need to feed the soil nutrients to help repair the lawn.

Testing Your Soil

You’ll have greater success growing healthy plants and groundcover if you test your soil and amend it based on the test results. You can purchase soil test kits at garden stores, or you can send a sample to a university extension for testing. Collect small soil samples from several different spots in your yard. Mix these samples together, then send a portion of it to the lab. Most labs provide a testing kit with a calibrated vial to contain the blended soil sample. Soil reports vary quite a bit in their thoroughness, but a typical report from an agriculture extension will note soil texture, pH level, and levels of essential nutrients, including nitrogen, potassium, and phosphorous. The report also will suggest fertilizer types and spread rates.

How to Collect Soil Samples

Collect small soil samples from several spots in your yard, and from multiple depths. You can use a shovel, trowel, or even a spoon to collect the samples. Or, you can purchase a soil probe that will give you neat samples with minimal disturbance to the surrounding turf. Mix the soil samples together in a small, clean plastic bucket. Blend the samples thoroughly. You may get a sample bag from a laboratory for this purpose. Prepare the sample by loading the specified amount of soil into the vial or bag provided with your kit. Complete the lab order form, indicating which plants you intend to grow. A basic test will provide your soil pH level and other information you need to determine whether your soil needs amendments.

OPTION: Use an instant-read tester to find and monitor the pH level in your soil.

Prepare the Site

Before you rent a power aerator or vigorously rake thatch from your lawn, prepare the site by removing weeds and replenishing soil moisture (if dry). You’ll have a tough time aerating or dethatching. Depending on the type and number of weeds, you can physically remove them or you can use a selective or nonselective herbicide to wipe out the unwanteds. For instance, if weeds are primarily broad-leaved, you can use a broad leaf herbicide on the entire lawn. (Then, wait two to four weeks before overseeding.) If crabgrass or patches of weeds are a problem, consider treating the spots with a nonselective herbicide that will kill all of the growth in that area. Be careful to protect the surrounding, healthy lawn. As its name indicates, nonselective herbicides don’t discriminate when they kill off growth. Always follow label instructions and wear proper safety gear, including eye and hand protection.

The best time of year to renovate your lawn is in the fall. But in many regions, this is also the time when lawns are most parched after a hot, dry summer. Replenishing moisture is an important step prior to dethatching, aerating, and overseeding a lawn. If the ground is too dry, the job will be more physically demanding as you try to loosen hard ground, and less effective because seed will not establish in a dusty soil profile. Soil should be moist to a depth of six inches before you begin working it, which could take days to achieve. Don’t rush this process.

Establish a Healthy Lawn

Removing thatch doesn’t have to be a back-breaking chore if you use power equipment such as a vertical mower (also called a verticutter) or an aerator. These two machines operate quite differently, but they can both accomplish the goal of loosening thatch from soil and creating more breathing room for healthy turf to receive water and sunlight so it will thrive. A vertical mower works by pushing tines into the soil surface to a depth of 1⁄8 to 1/2 inch. These tines pull up thatch in clumps, which then can be raked away. An aerator removes soil plugs, leaving cores of soil on the lawn that can be left to dry and break down back into the soil. If you choose to aerate a lawn with heavy thatch, go over the lawn three to five times and allow soil plugs to dry (or remove them) before overseeding.

You may decide to hire a professional to verticut or aerate your lawn. This equipment is also available for rent, so if you partner up with a neighbor, you can split the cost and share the aerator or verticutter for a day. You’ll save time and your back by preparing the lawn by machine. Dethatching by hand is best for small areas. Seasonal maintenance is an important ingredient to a healthy yard. Leaf collection in the fall and a gentle raking in the spring (after grass plants have reestablished) will allow air to feed the plants.

Lawn Renovation Tips

A lawn choked with weeds and excess thatch (left) will be more prone to bare spots and brown patches. Weed abatement, thatch removal, aeration, and reseeding create the proper conditions for healthy lawn growth (right).

Repairing Bare Spots

If your lawn is plagued with dying areas, you’ll need to determine the cause and take preventive measures to keep the grass from dying again. Once the problem is solved, sprinkle grass seed over the bare area, lightly rake it into the soil, and gently tamp the soil down. Keep the area moist for at least two weeks while the seed germinates. Use the following guidelines to resolve common problems:

 Dog Damage     Immediately water areas where the dog urinates. 
 Compacted Soil            Aerate the area, or till in an amendment, such as compost or peat moss. 
 Chemical Burn  Remove several inches of topsoil from the bare area.
 Disease                          Consult your local extension service for diagnosis + treatment.                
 Foot Traffic  Install a path or stepping stones to accommodate traffic.
 Insects                           Consult your local extension service for recommendations.                      

Reading Grass Seed Container Labels

The type of grass you select will play a large part in the success of your lawn. But it can be difficult to tell exactly what you’re buying. Whether it’s a prepackaged blend or seed sold by the pound in bulk, there will always be a label that tells you exactly what type of seeds are included in that blend.

 42%   Colonel Kentucky Bluegrass   88%
 33%                  Fine Perennial Ryegrass          78%                       
 21%   Red Tall Fescue  80%
 0.4%                 Inert Matter                                                            
 1.2%   Crop  
 2.4%                 Weed                                                                      

the percentage of seeds for each variety that are capable of growing. Germination: the portion of the pure seed that will germinate within a reasonable amount of time.
INERT MATTER: materials present in the blend, such as broken seeds, hulls, and chaff, that aren’t capable of growing.
CROP: the percentage of agricultural grain and undesirable grass seed contained in the blend.
WEED: the portion of weed seeds present in the blend.

How to Renovate a Lawn


1. Spot-treat weeds by applying selective herbicides using a pressure sprayer. Use a broadleaf herbicide to treat weeds such as dandelion and clover. Choose a nonselective herbicide for crabgrass and quackgrass. Be careful to protect healthy turf.

2. Remove thatch with a vertical mower. Set tines to rake 1⁄8" to 1/2" below the surface of the soil. Push the mower in straight passes. Then make a second pass over the entire lawn working in a perpendicular direction to the first passes. Cover the area in a grid pattern. Rake up and discard removed thatch.

3. Use an aerator to alleviate soil compaction and improve drainage by removing small cores of soil from the lawn. Run the machine across your lawn using the grid pattern described in step 2. Allow soil cores to dry partially, then rake them up. (Some can be left to decompose completely.) Follow by using a vertical mower or leaf rake to scratch and loosen the surface.

4. Use a broadcast spreader with a fertilizer blend (refer to soil report for appropriate NPK ratio). Calibrate the spreader according to instructions on the fertilizer package. Distribute the fertilizer evenly across the lawn. Fertilizer may need to be watered in before seeding. Follow by filling spreader with seed and distributing evenly.

How to Repair Lawn Damage


1. Moisten the damaged area, and use a garden fork to break up the soil. Rake out dead grass or other debris.

2. Spread grass seed over the repair area. Select seed that matches the grass type in your lawn— this often is a blend of several different types. Broadcast the seed at the coverage rate recommended on the package.

3. Fertilize the new grass plants with a grass seed starter formulation. Again, use the coverage rate specified on the package.

4. Water the repair area thoroughly, but not so much that you cause fertilizer granules or seeds to wash away. Install stakes and strings around the repair area to discourage foot traffic. Water the area daily until the new grass has established.