Why Does Your Ornamental Grass Look Dead?

Growing ornamental grass is fulfilling, especially when your plant is healthy and growing as expected. But just like other plants, ornamental grasses have their unique set of requirements that must be met for the plants to thrive. So why does your ornamental grass look dead? 

Ornamental grass looks dead when there is something wrong with it. This might be that your plant is getting too much or too little water, not enough nutrients, being attacked by animals and insects, or facing fungal diseases. Ornamental grasses can also look dead as they begin to age

Read on to learn more about the water and nutrient requirements of ornamental grass, how animals or insects impact it, the effect of diseases, and how to take care of aging ornamental grass.

Overview of Ornamental Grass Growth Requirements

Ornamental grasses, regardless of the specific type of plant, require nutrients, water, sunlight, and energy to grow. Without one of these important aspects, the plants would never reach maturity or would die as soon as they stopped receiving these crucial resources. 

If ornamental grass receives too little or too much of any of these requirements, it might also experience issues in growing.

Ornamental grass, like most other plants, engages in a process called photosynthesis in order to produce the energy it needs to survive. In this process, the grass absorbs carbon dioxide from the air, water from the soil, and sunlight through its stems to convert these materials into a sugar called glucose

When photosynthesis occurs, the plant releases oxygen into the atmosphere, essentially helping to “clean” the air of greenhouse gasses.

These three ingredients are not the only materials needed to keep the plant alive, however. In addition to energy, plants need other nutrients such as calcium, magnesium, and more to build and power the essential parts of their cells. 

Without absorbing these materials, plants wouldn’t be able to grow, and the important cell parts needed to engage in the process of photosynthesis would not exist. 

If an ornamental grass is beginning to look dead, it might be because it is not receiving enough water or other basic nutrients it needs to survive. It could also be that your ornamental grass is receiving too much water. 

When plants have more of a nutrient than they can absorb, the absorption stops, and these nutrients stay in the soil. In the case of water, unabsorbed water can wash away the nutrients needed or can block air from getting into the plant.

Factors That Influence the Appearance of Ornamental Grass

In addition to the lack or excess of their basic needs, such as light, water, and nutrients, ornamental grasses may also appear weak or dead due to the following factors:

Pest Infestation

An issue that can plague the health of ornamental grass is insects and animals potentially harming the plant. Just like humans and animals, plants can be attacked by these critters that might use the plant as food, a home, or for some other function. 

If your ornamental grass looks dead, it might be because the plant has been, or is currently, being attacked by pests.

The most common issues that occur are insect infestations in ornamental grass. Pest infestations make sense when you think about the qualities of ornamental grass.  

Ornamental grass provides a safe spot for insects to nest, lay larvae, or can provide a great source of food. Many pests will bite into the ornamental grass, sucking out the sap that contains the nutrients and energy the plant needs to survive.

Animals, depending on their size and diet, can also destroy ornamental grass in different ways. Some animals, such as mice, rabbits, and other small rodents, will eat the grass. 

If a large enough portion of the grass has been eaten, the plant can’t produce the energy it needs and consequently can’t heal the damaged areas. Larger animals, such as deer, coyotes, or even humans, can trample ornamental grass, preventing it from getting the sunlight it needs to survive. 

Ornamental grass damaged by animals and insects will present itself in different ways. 

Sometimes, the grass will take on a yellowish hue, while other times, it will appear dried out and dead. On some occasions, bite marks will be visible, while the grass can be uprooted entirely in more severe instances. These different symptoms of animal and insect attacks can make your grass look like it is dead.

Fungal Infection

Though less likely to be the reason for ornamental grass issues, these plants are subject to some diseases, especially because they often grow so close to one another.

When plants have diseases, like humans, they can pass them to one another through the stems or leaves of the plant. For fungal infections, just the act of plants touching one another can cause them to pass disease. 

The most common type of infection that impacts ornamental grass health is called rust. Rust is a fungal infection in which the fungi slowly destroy the outside and inside of the plant stems or leaves. 

Often, rust appears as small yellowish-red dots that occur on the outside of plants. Over time, these spots can cover the plant entirely, making it wither up, dry out, and die.

Rust and other fungal infections in ornamental grass are most common when the plant is moist. If it is being watered frequently from the top, the plant becomes the ideal spot for fungi to thrive and spread. Watering plants from the bottom, especially ornamental grass, can help keep the plant drier and prevent fungi from spreading.

If rust does occur on your ornamental grass, cut away the infected parts and treat the rest of the plant with a fungicide. Doing so will ensure that the fungi will not spread throughout the plant and will be less likely to impact neighboring plants.

Natural Decay Due to Age

When plants meet the conditions needed to survive, they are generally able to survive for a very long time. Today, the oldest tree in the world is over 4,500 years old. 

Unfortunately, most plants don’t die as a result of old age but instead, die from some other factors, such as pest infestation, disease, and improper care. Ornamental grass, though not growing nearly as old as some trees, can survive for long periods and can actually die of old age.

As ornamental grasses age, they become less able to create the energy they need to survive. This often results in the middle of the plant beginning to die first and the outer edges dying last, as they are technically younger than the center of the plant.

If you notice your ornamental grass is beginning to look dead, there is a strong chance that this is due to the age of the plant. Luckily, you can take steps to prevent old ornamental grass from dying. 

If you begin to notice the center dying as a result of age, divide the plant in half. By cutting the plant in half, the plant will require far less energy, and the rate of photosynthesis can catch up with new plant growth, essentially turning an old plant new again. 

For best results, divide your ornamental grass every two to four years.

Of course, by doing this, you are multiplying the number of grasses planted. If you don’t want to take care of too many plants but want to prevent an old plant from dying, divide the plant but let one of the divisions die. This will ensure you only care for one plant and will preserve the original plant’s life.

The best way to ensure your ornamental grass lives long enough is to take proper care by ensuring it receives all the nutrients it needs. Additionally, you should be on the lookout for common pests like aphids and mites that are known to infest ornamental grass. 

Final Thoughts

When it comes to caring for ornamental grass, there are many factors that can make your beloved plant look dead. The most common causes are poor amounts of water and nutrients, animal and insect attacks on the plant, disease, or old age. By taking steps to fight against all of these, you can keep your plant grass healthy for years.

If none of these reasons explain why your plant appears dead, contact a local professional for advice on caring for your plant.

Dr. Moritz Picot

Dr. Moritz Picot is a horticulture enthusiast and the founder of TheGrowingLeaf.com, where he serves as the lead content writer. He established the website in 2022 as a valuable resource for both gardening aficionados and beginners, compiling all the gardening tips he has accumulated over the past 25 years. Alex has a passion for nurturing plants, transforming backyards into inviting spaces, and sharing his knowledge with the world.

Recent Posts