Tall fescue is known for its drought, heat, cold, shade, and high-activity tolerance. And that’s why lawn owners in the northern regions prefer to have it.
Despite being a tough variety, it needs extra care in the summer season. Because it’s a cool-season grass that enters summer dormancy as soon as the temperature hits 85⁰F.
Let’s see how to take care of tall fescue grass in summer. We will take you through the exact maintenance procedures and steps you need to take.
1) Mowing
Tall fescue enters partial dormancy in summer, which means it grows very slowly. You still need to mow it, but less frequently than in the spring and fall.
Mowing tall fescue is important to maintain the optimal height. If you let it overgrow, it will invite diseases. Tall grass will reduce the airflow and create a moist environment, which is favorable for fungus.
And if you stop mowing or end up mowing too much, it’s an invitation to weeds. It’s the time when different types of weeds like crabgrass, nutsedge, and foxtail grow actively. When they see any bare space or weak grass, they take the opportunity and sprout.
Keep the Optimal Height
The recommended height to mow tall fescue is 3.0 to 4.0 inches. You can keep the height 3.0 inches in the spring and fall. But in summer, you should raise the mower deck and mow at 3.5 to 4.0 inches. The reason to keep the grass higher is the canopy effect. The tall grass provides shade to the soil and keeps it cooler. It reduces the evaporation rate, which is why there is more water available to the grass.
Secondly, when you mow high, you don’t disturb the lower part of the leaf blade where energy is stored. Thus, there is no energy wasted due to mowing, and the plant can survive the harsh weather and dormancy period.
While mowing the grass, you must make sure the blade is sharp enough. Dull blades can tear the grass tips and make it more vulnerable to diseases. The tips of the grass turn brown and make your lawn look horrible. A sharp blade is necessary to ensure a clean cut.
Get a Robot Lawn Mower
For most lawn owners, mowing the lawn is a big headache. Firstly, they don’t have time to mow the lawn. Secondly, they don’t like to deal with the issues of traditional gas mowers and the effort it requires. Just because of these, regular mowing of lawns is often neglected.
The best way to mow tall fescue in summer and year-round is by using a robot lawn mower. It automates lawn mowing and mows every area of your lawn whenever you want. You can set the time and desired height, and it’s ready to work. It keeps your lawn perfectly manicured in all seasons. The best part is that it saves you time, effort, and money.
For small lawns up to 0.25 acres, you can go with the Navimow i2 AWD. It’s a compact and affordable mower ideal for tall fescue. You can adjust the height from 2 to 3.6 inches and keep your tall fescue at the optimal height.
It is equipped with Xero-Turn™ AWD, which allows the mower to work on difficult terrain and take quick 180⁰ turns like a zero-turn mower. It uses Network RTK to navigate lawns and precisely cuts every corner. With VisionFence™, it detects 150+ obstacles and mows your lawn safely.
For large lawns up to 1.5 acres and powerful performance, the best choice is the Navimow X4 series. It has two powerful motors that can cut through thick, long, and dense grass without any hassle. You can adjust the mower’s height from 0.75 to 4 inches. It’s ideal for any type of grass and lawn.
With the All-Wheel Drive, Dual Suspensions, patented Traction Control System (TCS), and 5:5 balanced center of gravity, it works on difficult terrain. It mows waterlogged lawns, pitted surfaces, and steep slopes up to 84% (40⁰). It navigates large lawns with Network RTK, 360⁰ Vision, and VIO (Visual Inertial Odometry). Most importantly, it detects over 200 obstacles with AI-Powered 360° VisionFence™ and Animal Protection and mows your lawn without harming anyone or itself.
2) Watering
Tall fescue needs more water in summer compared to other seasons. The reason is the high evaporation rate, which deprives the grass of water.
Water at the Right Time
You have to water at the right time. Ideally, early morning is preferred, between 4:00 am and 9:00 am. The air is cooler, and the sun hasn’t risen, which means the evaporation will be slow. The water you provide to the grass will reach the roots.
Do not water during the mid-day as 30-50% of the water will evaporate. Watering at night is also discouraged as the soil stays wet for a longer period and invites fungus.
Provide Adequate Amount of Water
Now, the quantity of watering also matters. Tall fescue grass needs 1 to 1.5 inches of water per week. You can split it into two deep watering sessions. Shallow and frequent watering is not recommended, as water can evaporate quickly.
For the perfect amount of water, you must know the sprinkler rate. For that, you can place a few tuna cans in the lawn. Let the sprinkler run for 15 minutes. Measure the height of the water collected. Suppose it is 0.25 inches, which means the sprinkler rate is 1 inch per hour.
If your goal is 1 inch of water per week, you need to run the sprinkler for one hour. You can split it into two sessions of 30 minutes each, such as Sunday and Thursday. For more details, check out how long to water grass. Calculate the sprinkler rate and water your lawn the exact amount it needs.
3) Fertilization
Fertilizing tall fescue or any cool-season grass in summer is a big NO.
Cool-season grasses are in partial dormancy. They are hibernating to survive high temperatures. They have limited energy in their crown, and that is used to preserve roots to absorb water from depth.
When you provide fertilizer to a cool-season grass in summer, you force it to grow. The grass wakes up from hibernation and starts growing tips. Its focus shifts from roots to top-growth, and it spends all its energy. It results in a weak root system, which cannot support the new growth and provide the water it needs. Eventually, the grass dies as it cannot survive the harsh conditions.
The major risk of fertilizing in summer is fertilizer burn. Synthetic fertilizers are salts, and they absorb moisture from the grass blades and roots. When you spread them on the lawn, they quickly dry the grass. This process is called Osmosis.
The grass is left with no water. Secondly, it cannot absorb water from the soil as the evaporation is high in the summer season. The soil dries out quickly and cannot absorb the lost water. Because of a lack of water, the internal structure of the grass fails, and the grass changes its color to yellow.
In the worst case, the crown of the grass is dehydrated. It’s the place where the grass stores its energy. Once it is dried, the grass is dead, and there is no coming back. The grass won’t regrow in the fall. You have to reseed the lawn.
It means fertilizing tall fescue in summer will result in extreme harm rather than doing anything good.
If you use a robot lawn mower on your lawn, it will do micro-clippings. Which means it will finely cut the grass tips. These fine clippings can easily break down within 24-48 hours and provide free fertilizer to the lawn.
Further reading: Can I fertilize my lawn in summer?
4) Pest and Disease Management
The Brown Patch (Rhizoctonia Solani)
The brown patch is a major summer disease in tall fescue. You will witness circular brown patches at different locations in your lawn. Keep in mind that your whole lawn won’t be brown; only a few spots will be because of the soil-borne fungus Rhizoctonia Solani. You might also notice a grayish smoke ring, which is due to the active fungus.
This disease is common in hot and humid weather. When the sum of night temperature and humidity is around 150, it creates a favorable environment, such as (75⁰F at night + 75% humidity). The fungus appears and thrives when the grass blades remain wet for more than 10 hours. Thus, you should not think about watering in the evening or at night; early morning is the right time.
If your lawn is affected by Brown Patch (Rhizoctonia Solani), you should stop nitrogen supply first. Never fertilize such a lawn. Secondly, check your watering routine. It should be early in the morning. Remove long branches and blockages to improve airflow in the lawn. Lastly, mow regularly and do not let the grass grow over 4 inches.
You have to treat the lawn with an appropriate fungicide. You should opt for Azoxystrobin (Group 11) or Fluoxastrobin. The grass will absorb the chemical and recover over time. If you have a history of the brown patch, you can apply a fungicide before it happens.
Grubs
Grubs are extremely common in the summer. These are the larvae of beetles that live underground and feed on the root system. They eat the roots and disconnect them from the plant. Thus, if there are grubs in your lawn, they will separate the water source of the grass, which is much needed to survive summer.
When grubs are eating grass roots, the grass cannot absorb enough water. Eventually, it turns brown. So, if there are brown patches in your lawn even after watering adequately, the probable cause could be grubs.
You can do a quick carpet test. Grab a handful of grass and pull straight up. If it comes out effortlessly, it means there could be grubs underneath the soil. Dig a small hole, and you will find grubs. They stay at the top 1-2 inches of the soil. But if it does not come out, it means the grass is fine. It is actually a sign of drought.
Secondly, you will also see some birds, skunks, or raccoons around the soil. They gather to eat grubs.
To deal with grubs, you need Dylox (Trichlorfon) or Carbaryl. It will kill them within 24-48 hours. After application, water the lawn immediately around 0.5 inches. It will allow the chemical to reach the root zone where the grubs are.
5) Extra Care for Tall Fescue Summer
Limit Foot Traffic: Tall fescue is dormant in summer, so you should limit foot traffic as much as possible. Higher foot traffic will damage the grass and compact the soil.
Use a Lightweight Mower: A common reason for soil compaction is the heavy weight of the mower. You should opt for a lightweight mower; robot mowers are the best. It is not only beneficial for summer but for all seasons.
Provide Shade: In summer, the soil temperature is extreme. It cooks the roots of your grass. If possible, you can provide shade to the lawn through physical shade structures, trees, or mowing higher. It keeps the soil a bit cooler and reduces evaporation.
Opt for Bio Stimulants: Fertilizers aren’t recommended in summer. However, you can use bio stimulants. For instance, liquid iron can help your lawn turn green without adding nitrogen. It provides a deep green color without forcing growth. Similarly, Kelp provides natural hormones that help plants tolerate heat, and humic acid improves the soil’s ability to hold water and nutrients.
Sharpen/Replace Mower Blade: Sharpen the lawn mower blade every 20-25 hours of use. Here is our guide on how to sharpen lawn mower blades. If you use a robot lawn mower, you just need to replace the blade every 100-150 hours of use.
Final Words
Tall fescue is a cool-season grass that needs extra care and attention in the summer season. It enters hibernation to survive extreme temperatures, which is why providing an adequate amount of water, mowing regularly, avoiding fertilizers, and controlling pests/diseases is necessary. We have explained how to take care of tall fescue grass in summer and take extra precautions to keep your grass alive and healthy. You only need to follow this special routine for summer, and your grass will start growing actively in the fall.
