What Does Annual Bluegrass Look Like?

When most people think of bluegrass, they likely imagine the Kentucky variety that is used for horse pastures. However, annual bluegrass is another type of turfgrass that is commonly used in lawns and gardens, but can also turn into an undesired weed if it grows in an area it’s not supposed to.

With Annual Bluegrass, as with any other type of weed, it’s important to be able to identify any problems or issues early on, so that you can address them accordingly.

That’s why in this blog post, we’ll be discussing the identifying characteristics of Annual Bluegrass, as well as where it grows and how to get rid of it. This way, we’ll answer the question, What does Annual Bluegrass look like? Time to get started!

What is Annual Bluegrass?

Annual bluegrass is one of the most prevalent weeds in the United States and across the world, especially in North America.

Poa Annua is the scientific name for this plant, which has also been known as Annual Meadow Grass, though its most popular name is Annual Bluegrass. It is an annual weed that grows in temperate regions.

It is so widespread that many home and business owners use it as grass. For example, Annual Bluegrass is utilized on putting greens at the world famous Oakmont Country Club golf course in Pennsylvania, as well as other golf clubs throughout the United States.

Where Does Annual Bluegrass Grow?

Annual Bluegrass is an annual weed, which means it grows for one year, casts seeds around it across the meadow, grassland, or yard that it’s in, and then dies.

It germinates in the late summer and fall, when soil temperatures drop below 70 degrees Fahrenheit (or 21 C), and it continues to sprout through the winter. It’s quite quick and efficient at seed propagation, so a single tiny plant might produce up to 100 seeds in just two months.

It’s difficult to completely eliminate this weed because it has thin roots and develops fast. It spreads quickly and thrives in wet climates, such as those with a lot of rain or irrigation. It usually withers and dies during the hot heat of summer, and might leave ugly brown stains on your lawn.

How to Identify Annual Bluegrass

You’ve undoubtedly noticed Annual Bluegrass around you all your life; it’s quite popular and can be found in almost every town and street in the United States. So, what visual traits should you look out for to better identify this weed?

Visual Characteristics 

Annual Bluegrass is a low-growing weed that grows only 6-10 inches tall, though it will most likely stand out above your regular lawn grass. It forms clusters as it grows, and its grassy stem portions are usually somewhat flattened and boxy in appearance, and rough and serrated along its edges.

There are tasseled, flower-like pods at the top of these stems, and they grow 1-2 inches long and are a paler green in color. Annual bluegrass has smooth, vivid green, oval leaves that are blunt at the end and have a boat-shaped tip. It has greenish-white seed blooms throughout its life cycle, most of which appear in the spring months.

If you happen upon a large infestation of the weed, all of the plants’ tops will appear to merge together into a white-green feathery cloud that seems to hover over the grass like fog.

Growth Stages

The plant develops quickly from seed, blooms in about 6 weeks, and then dies. It is in bloom all year round except for harsh winters. The seeds mature and are dispersed throughout the year.

Other Unique Traits

There’s nothing else to mention for Poa Annua and its identifying visual characteristics.

Plants That Look Like Annual Bluegrass

One close relative of Poa Annua that people tend to mix up is Kentucky Bluegrass. For one distinguishing feature, the color of annual bluegrass is usually lighter and more lime-green than that of Kentucky bluegrass.

However, to make a more accurate distinction, one should look at the ligule, which is a small appendage at the leaf blade’s base, more closely on both grasses. On annual bluegrass, the ligule is long and membranous (like scotch tape in appearance), but it is either short or does not exist on Kentucky Bluegrass.

How to Get Rid of Annual Bluegrass

Poa Annua is a hardy weed that is difficult to get rid of from your grass or garden since it is so resilient and spreads fast. If you don’t want the plant to run wild throughout your whole lawn or garden, you must get to work quickly identifying where it’s growing and working to stop it.

When it comes to getting rid of Annual Bluegrass, the first thing you should do is get rid of any plants that are beginning to take over your grass. You can use a mixture of vinegar, oil soap, and dish soap as an organic herbicide spray to eliminate all of the weeds on your lawn. Boiling water can also be used to eliminate weeds in the same manner; pour the water straight from a kettle over the weed a few times a week until it dies.

The best chemical weed killer for Annual Bluegrass is a pre-emergent herbicide, which is composed of particular fertilizers that not only destroy the plant but also keep it from germinating for one full year.

You want to use any weed killer that has the active ingredient glyphosate. It works by preventing new weeds from developing and stopping the seed germination process before it begins. Apply the product in the fall, so there’s time for it to work over the winter, as well as early spring, when the weed is actively growing.

Summing Up

Annual bluegrass can be a pesky weed to get rid of, but with the right information, you can eradicate it and keep your lawn healthy. We’ve covered all you need to know about annual bluegrass in this post, from its appearance and growth habits to how to identify it and get rid of it.

Now that you’re an expert on the subject, put your knowledge into practice and enjoy a weed-free lawn this season! We hope this blog post has been beneficial to you and your lawn, and will help you keep your lawn healthy and free from this invasive weed species. Have you had experience dealing with annual bluegrass? What tips do you have to share?