What are Grass Plugs and How to Use Them

In this week’s blog post on Sod University, we explore a few questions on grass plugs and how/when to use them. Read below to find out the common purposes a grass plug serves and how to care for them, and follow our progress in a plug planting we conducted here at the Sod Solutions office. Be sure to also check out our guide on How to Properly Install Grass Plugs for more information.

What is a grass plug?

A grass plug is an individual turf plant that is grown in a tray; their size can vary, but generally an individual plug measures anywhere between 1.5–3 inches in length/width. Planted from 9–12 inches apart, they will continue to spread and fill in over time, creating a solid ground cover of your preferred grass type.

The two left images below show a tray containing EMPIRE® Zoysia plugs, while the right two images are of a tray containing 1.5 inch CitraBlue™ St. Augustine plugs.

When are grass plugs used?

Grass plugs are typically used in one of two instances: to repair damaged areas of a lawn, or to establish a lawn when sod or seed is not available or not practical.  You can also purchase a small plug tray to test out how well the certain breed of grass will perform in yard—like areas of shade, full sun or even areas that receive too much rainfall. In short, a tray of grass plugs is to warm season grass what a bag of grass seed is to a cool season grass. However, Sod Solutions still offers cool season grass plug varieties. Learn more about the differences between warm and cool season grasses and where they tend to grow.

– To repair damaged areas of an existing lawn: 

If you have a lawn with small areas of damage (caused by insects, disease, dog urine, etc.), grass plugs are an ideal way to repair these areas, but first, you must address what is causing the damage (apply an insecticide, fungicide or keep your dog from urinating on your lawn). Once you have controlled what is causing the damage, installing plugs in the damaged area is the quickest way for your lawn to return to its thick, lush former self.

Below are photos of two sections of disease damaged Palmetto® St. Augustine grass that have been plugged with CitraBlue™ St. Augustine grass, which exhibits improved disease tolerance. How far apart you space the plugs will determine the rate that the plugs fill in to create a solid ground cover. These areas have been plugged fairly close, ensuring a quicker grow in.

– To establish a lawn when sod or seed is not readily available or practical:

Grass plugs are alternatively used when sodding or seeding a lawn is not possible or practical. Examples of this include when:

• The grass variety you want is not grown by any nearby sod farm,
• The amount of grass you need is much less than a pallet of grass and individual pieces of sod are not available for sale nearby,
• It is not possible to transport pallets of sod to the installation site,
• The type of grass you are wanting is not available as a seed. For example, there’s no such thing as St. Augustine seed, so grass plugs are the next best option.

Another example of this is Bella® Bluegrass. Bella Bluegrass is an improved bluegrass that is not grown or sold as sod—only as plugs.  It requires little to no mowing and is ideal for very small yards or for homeowners who want a low maintenance lawn. Below are photos showing Bella plugged and growing over time in a small lawn area.

Below is an example of a job site at a rooftop metropolitan apartment where it was not possible to deliver pallets of sod. Instead, the homeowner planted grass plugs to install their small lawn area.

Follow our progress in a recent plug planting

Last summer, we at Sod Solutions undertook the task of growing in plugs in two large test plots at our office (two 25 ft. x 25 ft. plots) of our newest grass varieties: Innovation™ Zoysia and CitraBlue™ St. Augustine.  We planted approximately 500 plugs of each variety—seven 72-cell plug trays each. The purpose of the plots is largely research, but the project does give us the opportunity to document the process and progress of the grow-in in a large area from grass plugs. Below are the steps we followed in planting plugs at our office. You can also follow these steps for your own purposes.

Step 1:

We set up stakes around the edges of the plots to make a perfect square. Then, we applied several applications (2 apps. 10 days apart) of glyphosate to kill the existing turfgrass groundcover and raked out the dead plant material, leaving a clean surface to work with. Next, we measured a grid formation so that each plug would be planted 12 inches from each other. Lastly, we used spray paint to indicate where each plug would be planted.

Step 2:

On each spray-painted marker, we used a drill and a three-inch auger bit to dig into the ground and created a hole for the plugs to be planted in.

Step 3:

After planting each plug and covering up any loose spaces with soil, we soaked the soil and then fertilized the plugs with Lawnifi’s Grow, an excellent source of highly available phosphorus, which the grass plugs need for root growth. Because the grass plugs are little plants with fully intact roots, they are not as susceptible to drying out as sod. We watered our plugs every morning for the first two weeks, except for when it rained. After that, they were watered only two times a week or as needed for the following two weeks. Four weeks after planting, we fertilized again with Grow. After another four weeks, totaling eight weeks after planting, we fertilized with Lawnifi’s Maintain. The three bottles of fertilizer came in a New Lawn Starter Box, which is the suggested fertilizer program for newly laid sod or planted grass plugs. After eight weeks, the plugs are aggressively growing and spreading. Our current issue is weed management. You can learn more about Lawnifi at Lawnifi.com.

See before and after pictures of the plugs at our office when we planted them on May of 2019 and 14 months later in July of 2020.

Pictured above from left to right: CitraBlue St. Augustine plugs in May of 2019, CitraBlue St. Augustine plugs in July of 2020, Innovation Zoysia plugs in May of 2019 and Innovation Zoysia plugs in July of 2020.

If you are interested in learning about our grass plug planting progress, read our updates here: Fall Grass Plugs Update, Spring Grass Plugs Update and Summer Grass Plugs Update. These two articles will also inform you of any maintenance or obstacles we encountered as the plugs established. We will continue to follow up with relevant updates or other tools we end up using to help these plugs grow.