What type of grass do I have? How to identify your lawn

Start with where you live

Lawn grasses fall into two groups. Cool-season grasses grow fastest in spring and fall, when temperatures sit between about 60 and 75 °F, and can stay green through a mild winter. Warm-season grasses grow fastest in summer heat and go dormant, turning tan, after the first hard frost.

That split follows the climate. In the northern U.S., Canada and northern Europe, almost every lawn is a cool-season grass: Kentucky bluegrass, perennial ryegrass, tall fescue or fine fescue. Across the southern U.S. you will mostly find Bermudagrass, zoysiagrass, St. Augustinegrass, centipedegrass or bahiagrass.

In between lies the transition zone, a band running roughly from Kansas and Missouri east to Virginia and North Carolina. Summers there are too hot for most cool-season grasses and winters too cold for many warm-season ones, so lawns are often tall fescue, zoysia or Bermuda, or a mix.

Common lawn grasses by region

Climate narrows the list, and so do soil and rainfall. The table shows what you are most likely to find in each part of the U.S. Edges blur, and a shady corner or fresh sod can break the pattern, so treat it as a starting point and then check the blades.

Watch what the lawn does through the year

If you have lived with the lawn for a year, you already hold a strong clue. A lawn that turns straw-colored after the first frost and stays brown all winter is a warm-season grass. A lawn that stays green in a mild winter but thins and browns in a hot, dry July is a cool-season grass under heat stress.

Patches that green up weeks before or after the rest of the lawn usually mean you have more than one grass. Note where they are and check each one separately.

Dig up a plug and see how it spreads

Lift a piece of turf about the size of your palm with a trowel, keeping some soil on the roots. Shake it gently and look at what holds the grass together. This one check removes about half the candidates.

• Stolons: runners that creep along the top of the soil and root at each joint. Bermudagrass, St. Augustinegrass, zoysiagrass, centipedegrass and buffalograss all spread this way.
• Rhizomes: runners that travel just under the soil and send up new shoots. Kentucky bluegrass spreads by rhizomes, and so do Bermudagrass and zoysiagrass, which have both kinds.
• Bunch type: shoots grow from one crown in a tight clump, with no runners. Perennial ryegrass, tall fescue and most fine fescues grow this way, so bare spots do not fill in on their own.

Look closely at one blade

Pull a single shoot and look at it in daylight, with your phone camera zoomed in if you need to. Four details separate most lawn grasses.

Grass identification chart

Use this chart once you know your season group and how the grass spreads. The best clue column is the check that usually settles it.

Let the seed heads do the work

If the lawn has gone a week or two without mowing, look at the seed heads. They are some of the clearest clues there are.

• Bermudagrass: three to seven thin spikes fanning out from one point, like the fingers of a hand.
• Bahiagrass: a tall stalk ending in two spikes that form a V, often well above the rest of the lawn.
• Crabgrass: several finger-like spikes too, but on a wide, light green, sprawling plant that dies in the first frost.
• Annual bluegrass: small, whitish, open seed heads that appear even on a short-mown lawn in spring.

Weedy grasses that move into lawns

Not everything grassy in a lawn is the grass you planted. Crabgrass forms pale, wide, flat clumps in summer and dies in fall. Annual bluegrass is lighter green and sets seed in spring. Quackgrass has long white rhizomes and clawed auricles that wrap the stem. Nutsedge looks like grass but is a sedge: roll the stem between your fingers and you will feel three edges.

Knowing the difference matters because the fix differs. Crabgrass is best stopped with a thick lawn and a pre-emergent in spring, while nutsedge needs its own treatment. Read the product label before you use any of them.

Check the seed bag or sod receipt

If the lawn was seeded or laid in the last few years, the paperwork may answer the question for you. A bag of grass seed lists each grass and its share by weight, such as 40% Kentucky bluegrass and 30% perennial ryegrass, along with other crop seed and weed seed. Sod is usually sold as a named variety, such as Palisades zoysia, Floratam St. Augustine or Tifway 419 Bermuda.

Read a seed label with care. The percentages are by weight, and Kentucky bluegrass seed is tiny, with several times more seeds per pound than ryegrass. A blend that is only 20% bluegrass by weight can still make up a large share of the plants once the lawn fills in.

No paperwork? Ask the previous owner, the builder or the lawn care company. A sod farm can often tell you which varieties it sold in your area.

Mow it at the right height

Once you know your grass, set the mower to match. Mowing too short is one of the most common reasons lawns thin out and fill with weeds. The ranges below are typical extension recommendations. The right setting depends on your variety and climate, so cut toward the high end in heat or shade.

When to ask an expert

If you have checked every clue and still cannot decide, or a grass that looks different is spreading fast or dying out in patches, get a second opinion. Your county extension office or a good local garden center can usually name a grass from a fresh sample, and extension offices often do it for free or a small fee.

Bring a plug about 4 inches across with roots and soil, sealed in a plastic bag, plus a seed head if the grass has one. If you are planning a renovation, ask about a soil test at the same time. It tells you the pH and nutrients before you pick a grass to plant.

Take a photo that an identifier can read

A photo identifier is a quick way to get a short list, as long as the photo shows the details above. Use daylight, get down to grass level and fill the frame with a few blades. Dry grass photographs better than wet grass, and a plain background, such as a sheet of paper behind a pulled shoot, helps a lot.

Take a second photo of the runners or the clump, and add your region in the notes. Then upload it to the free grass identifier and compare the result with the shoot in your hand.

Frequently asked questions