Are you noticing your once lush and vibrant ornamental grasses turning brown?
Don’t panic just yet! There are several reasons why this may be happening, and with a little bit of knowledge and care, you can bring your grasses back to their former glory.
In this article, we’ll explore the common causes of brown ornamental grasses and provide tips on how to prevent and treat them.
So, grab a cup of coffee and let’s dive in!
Why Are My Ornamental Grasses Turning Brown
There are several reasons why your ornamental grasses may be turning brown. One of the most common causes is lack of water. If you notice browning leaves or blade tips, it may be a sign that your grass needs more water. Check the soil to see if it’s cracked, which is a sign that it’s too dry. If the container mix appears dry and is separating from the container, it’s also a sign that your grass needs more water.
On the other hand, overwatering can also cause brown ornamental grasses. Most types of ornamental grasses don’t need excessive watering as they don’t thrive in overly moist soil. After watering your grass, give it some time before re-watering to ensure that it doesn’t lack water or have excess water.
Another common cause of brown ornamental grasses is fungal diseases such as powdery mildew and rust. Powdery mildew builds on plants that are in shady and warm and humid conditions, while rust causes yellow, red, or orange blisters to appear on the leaves. To prevent these diseases from attacking your grass, ensure proper air circulation between the plants by planting them farther apart from each other.
Mites and aphids can also cause brown ornamental grasses by sucking their nutrients. Mites are too small to see with the naked eye, but you can spot their presence through the webbing they leave on the plants. Aphids are bigger and can be seen on a plant’s stems or leaves. Both can be controlled by soaking your grass with a garden hose or applying insecticidal soap spray.
Lastly, temperature fluctuations, excessive fertilization, bacteria, disease, and natural pests can also cause ornamental grasses to turn brown.
Overwatering
Overwatering is a common mistake that can lead to brown ornamental grasses. Most types of ornamental grasses don’t need excessive watering as they don’t thrive in overly moist soil. If you overwater your grass, it might become more susceptible to fungal diseases like powdery mildew, which leaves your plant with spotted brown leaves. This disease usually occurs when you don’t use suitable soil for your plant and when it doesn’t receive enough sunlight. Fungal infections spread fast in moist and shady environments, so it’s crucial to avoid overwatering your ornamental grass.
Another common problem caused by overwatering is root rot. This condition occurs when the soil is too moist, causing the roots to rot and die. Once the roots are damaged, the entire plant turns yellow, brown, and eventually black as it dies. To prevent root rot, ensure that your grass is not sitting in water and that the soil has proper drainage.
To avoid overwatering your ornamental grass, give it some time before re-watering after each watering session. This will ensure that your grass doesn’t lack water or have excess water. Additionally, make sure to use well-draining soil and containers with drainage holes to prevent water from accumulating around the roots.
Underwatering
Underwatering is a common cause of brown ornamental grasses. Every grass species needs adequate water to thrive, so drought conditions or excessive heat could be preventing your grass from getting enough water from the soil. This is a common cause of brown spots in lawns, especially for homeowners who have grass species that don’t hold up well to higher temperatures. If your grass is not getting enough water, it will likely start to wilt before turning brown. The browning will typically occur across your entire lawn and not in small sections. You might also notice that the grass blades don’t spring back up after you step on them and instead hold your footprints.
To prevent underwatering, water your ornamental grasses during dry weather days so that the soil stays moist. However, don’t overwater your grass as this can also cause browning. After watering, allow time for the soil to dry between waterings to ensure that your grass doesn’t lack water or have excess water. If you’re unsure about how often to water your ornamental grass, check the soil moisture by sticking a finger into the soil. If it feels dry, then it’s time to water again.
Fungal Diseases
Fungal diseases are a common cause of brown ornamental grasses. Anthracnose is a group of fungal diseases that can affect ornamental or turf grasses. It causes lesions to appear on leaves, stems, fruits, or flowers. Anthracnose fungi thrive in moist conditions, so they shouldn’t affect ornamental grasses in dry places. Symptoms of anthracnose include areas of brown or thin grass developing, or black, hair-like growths appearing on dead grass.
Powdery mildew is another fungal disease that can affect ornamental grasses. It builds on plants that are in shady as well as warm and humid conditions. This disease leaves your plant with spotted brown leaves. Rust is another common problem with ornamental grasses. It might cause your plant to turn brown (or yellow). To fix the issue, consider getting a fungicide and transplanting your ornamental grass to a sunnier location.
To prevent fungal diseases from attacking your grass, ensure proper air circulation between the plants by planting them farther apart from each other. Overwatering your ornamental grass might make it more susceptible to fungal diseases. Therefore, it’s important to water your plants properly and avoid overwatering them. Additionally, using suitable soil for your plant and ensuring it receives enough sunlight can also help prevent fungal infections from spreading fast in moist and shady environments.
Insect Infestations
Insect infestations are one of the major causes of brown ornamental grasses. Two common types of insects that attack ornamental grasses are aphids and mites. Aphids kill grass by sucking out sap from the underside of blades, while mites suck the juices from the blades, making the infected parts yellow. Unlike aphids that you can see with your naked eye, mites cannot be seen. However, you can see their webbing on the grass.
Grass lace bugs are also a potential threat to ornamental grasses. They produce stippling on the upper and lower blade surfaces which can coalesce to cause large areas of the blades to turn light brown. High populations of grass lace bugs not only reduce the aesthetic value of their grass hosts, but the feeding damage also produces severe plant stress. Grass lace bugs can potentially kill plants, particularly recently established ornamental grass plants.
To prevent insect infestations, it’s important to keep your ornamental grass healthy as possible by providing proper care and maintenance. Avoid over-fertilizing your plants as this can attract insects. Also, avoid overcrowding your plants as this can lead to poor air circulation and create a favorable environment for pests and diseases. If you notice an insect infestation, you can control it by soaking your grass with a garden hose or applying insecticidal soap spray. Just be sure to select ones that don’t kill beneficial bugs.
Environmental Stress
Environmental stress is another factor that can cause ornamental grasses to turn brown. Grasses are sensitive to changes in temperature, humidity, and light intensity. When exposed to extreme temperatures or dry conditions, they may go into dormancy and turn brown as a way of conserving energy and water.
Grasses that are adapted to cooler temperatures, such as cool-season grasses, may turn brown during the hot summer months. Conversely, warm-season grasses may turn brown during colder months when temperatures drop. It’s important to choose grasses that are appropriate for your climate and growing conditions to avoid stress-related browning.
Excessive fertilization can also cause environmental stress and lead to browning of ornamental grasses. Fertilizers contain high levels of nitrogen, which can stimulate rapid growth but also make the plant more susceptible to disease and stress.
Natural pests such as insects and animals can also cause environmental stress by feeding on the grass and damaging its roots or leaves. This can lead to browning and even death of the plant if left untreated.
To prevent environmental stress from causing your ornamental grasses to turn brown, it’s important to provide them with proper care and maintenance. This includes watering them regularly but not excessively, choosing appropriate grasses for your climate, avoiding over-fertilization, and controlling pests through natural or chemical means if necessary.
Pruning Techniques
Pruning is an essential part of maintaining healthy and attractive ornamental grasses. It helps to remove dead or damaged foliage, promote new growth, and prevent the spread of diseases. The best time to prune your grasses depends on whether they are warm-season or cool-season grasses.
For warm-season grasses, pruning can be done in late fall after the foliage has turned brown or in early spring before new growth appears. If you live in an area where fire can be problematic, it’s best to trim your warm-season grasses to just a few inches tall. However, if fire isn’t a concern, leaving the dried grasses and seed heads in your garden can provide winter interest and food for birds.
When pruning warm-season grasses, use pruning shears or hedging shears to cut the grasses down to a height of 3 inches if the grass stays under 3 feet tall. For taller varieties that grow above 3 feet tall, trim to a height of 6 inches. It’s important not to cut too low as this can damage the crown of the plant and cause rot.
For cool-season grasses, rejuvenation pruning should be done every two or three years. This involves using pruning shears or hedge trimmers to remove no more than two-thirds of the plant. Cutting back too much might allow moisture to gather on the crown, which causes rot. It’s also important to comb through these plants after the growing season to discard any brown foliage that piles up inside them. Use rubber gloves and run your fingers through the grass like you are combing hair. The brown blades cling to the gloves and come out easily, triggering the plant to refresh itself.
Regardless of whether you have warm-season or cool-season grasses, it’s important to wear long sleeves and gloves when pruning as some ornamental grasses have sharp leaves. You can also wrap a rope, bungee cord, or masking tape around the outside of the grass to form a tight bundle. This will not only help with cleanup but also make the job of pruning easier. Additionally, dividing your grasses every few years can help rejuvenate them and keep them attractive.
