Steps for Overseeding Your Colorado Lawn

Steps for Overseeding Your Colorado Lawn

Over time yards can thin and appear dull due to use and compaction. The solution to this problem is to enhance your lawn with healthy young grass, a process known as overseeding. This will fill in bare spots and thicken your lawn.

In this guide you’ll learn:

  1. Signs that it is time to overseed
  2. What is overseeding?
  3. What time of year should I overseed?
  4. Things you’ll need
  5. Steps to overseeding your Colorado lawn

Signs That it is Time to Overseed Your Colorado Lawn

Overseeding has a number of benefits that result in a healthier lawn. A healthy and dense lawn can lead to less weeds. Also, by using a blend of disease-resistant grass seed varieties, you can work to prevent disease in the future. You’ll want to consider overseeding if the lawn:

  • is high-use and showing signs of wear and tear from kids and pets
  • has bare or dead spots
  • is thinning, patchy, or dull in color
  • has a weed problem

Signs That it is Time to Overseed Your Colorado Lawn

NOTE: DO NOT overseed your lawn if you have applied a pre-emergent weed killer to it. This will prevent your grass seeds from germinating.

What is Overseeding?

Overseeding is spreading new grass seed over an existing lawn to encourage new, thick, green growth. Overseeding sounds very simple but there are a number of steps you will need to follow to ensure your seeds have a high chance of germinating.

What Time of Year Should I Overseed?

For Colorado’s climate, the best time to overseed is in April or September. During these times, temperatures are cooler and moisture can be more abundant. This results in better germination and improved vigor of the newly germinated seedling.

Steps to Overseeding Your Colorado Lawn

1. Mow the Lawn

You’ll want to mow your lawn a little shorter than usual to give the seeds a higher chance of making soil-contact so they can germinate. Be sure to not scalp the existing grass. A good grass height is around 2 inches tall.

2. Aerate

Aerating opens the turf canopy and reduces compaction allowing for the seed to drop to the soil level. If you are not sure how to aerate, check out this complete guide.

3. Select the Right Grass Seed

You’ll want to select a grass seed blend that is the same type as your lawn. The two most common types of turf grass grown in Colorado are Kentucky Bluegrass and tall fescue.

4. Use a Drop or Rotary-spreader to Spread the Grass Seed

When going over the lawn, it’s important to remember that more seed does not mean more grass. When using a drop spreader, it is important to overlap your lines slightly. It is recommended to go in two perpendicular directions at a half rate (using half the amount going one direction and half the amount going the other direction) to ensure even coverage. Seeding rates for Kentucky Bluegrass are 0.5 lbs to 1 lb per 1000 sq. ft and 3 lbs to 4 lbs for fescue. Aerate your lawn in straight lines trying not to go over the same spot twice.

drop spreader instructions for overseeding

5. Use a Leaf Rake or Verticutter on the Lawn

This will ensure that the seed comes in contact with the soil.

6. Take a Soil Sample to Determine if You Need to Fertilize

You can purchase a do-it-yourself soil test kit to determine the nutrient-level of your soil. Apply a quick release fertilizer that is high in phosphorous, such as 18-24-12 starter fertilizer blend if the soil sample indicated a need for nutrients. Learn more about why soil pH matters.

7. Make Sure to Water Properly for the Best Results

It is really important to make sure that once the overseeded grass is watered, it remains moist during germination. Be careful not to overwater or the seeds will drown. Depending on the time of year, you may need to water 2-4 times a day in short-duration-bursts to keep from overwatering and washing the seed away. If a seed is left to dry out after it has taken up water, it will not survive.


Your new grass seeds will begin to sprout after 2-5 weeks for Kentucky Bluegrass and 7-10 days for fescue. Overseeding is a process, but following these steps properly will ensure a beautiful lawn that will last for years to come. Need some help overseeding your lawn and your landscape maintenance? Timberline’s personal gardeners are experts in all things landscaping so relax and enjoy your little bit of heaven. Contact us today!