Summer Care Tips for Your St. Augustine Lawn

Summer is here! When it comes to inviting guests over, lawn care nuts like us enjoy having the best-looking yard on the block. Sod University combines a few summer maintenance tips for your St. Augustine lawn. Be sure to also check out our series of Homeowner Maintenance Guides for generic St. Augustine, Palmetto® St. Augustine and CitraBlue® St. Augustine.

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1. Keep Up with Summer Mowing (and Reduce the Time Spent on This Chore)

Summer mowing is one of the most dreaded outdoor chores as temperatures rise and physical exertion becomes exhausting. It’s even more annoying that you have to keep up with frequent mowing because when the grass gets too tall, the lawn mower becomes harder to push.

St. Augustine mowing heights during the summer generally range from about 2–4 inches in height, however, if your St. Augustine is located in partial shade, keep the mowing height to 3–4 inches. Take a look at the mowing heights for certain St. Augustine varieties below.

• Palmetto St. Augustine: 2–2.5 inches
• CitraBlue St. Augustine: 2–3 inches
• Floratam St. Augustine: 3–4 inches

A good rule of thumb is to never remove more than a third of the leaf blade at a time. If more than this amount is removed, the grass will stress and turn brown for a short period of time.

If you are returning from a summer vacation, you may have to mow multiple times to get the grass back to its desired height. Be sure to wait about 3–5 days between each mowing.

Note: Get ahead of summer mowing and check out our tips on reducing time spent mowing your lawn as it gets hotter outside: How to Mow Your Lawn Less During the Summer.

2. Keep Your Heat-Stressed St. Augustine Strong with the Right Summer Fertilizer

St. Augustine grass, as well as any type of turfgrass, requires different nutrients as seasons change. This is because outdoor temperatures change throughout the year and, as a result, so do soil conditions.

Your St. Augustine lawn will more than likely endure some form of stress from the summer heat. It’s important to feed the grass with the appropriate amount of nutrients to help out with this stressful period by using a summer lawn fertilizer.

Grass requires less nitrogen in the summer than it would in the spring when it’s coming out of dormancy and trying to green up. Nitrogen promotes new growth, which will not survive in the heat of the summer. The wrong fertilizer combined with excess sunlight during the summer can easily cause scorched spots in your yard.

Sod University recommends two different fertilizer options for the summer, however, you will only need to use one of the two options for summer fertilization. Using both at the same time may result in burns in your lawn.

Option 1: Our first recommendation is the Lawnifi® Summer Fertilizer Box, a liquid fertilizer program designed to give St. Augustine lawns the nutrients they need to survive and flourish during the hot summer months.

With one bottle of Maintain and two bottles of Recover, the Summer Fertilizer Box’s application schedule will give your St. Augustine nutrition all summer long. Maintain’s 16-0-4 formulation works to fortify your lawn with potassium, amino acids and carbon.

Recover’s 13-0-0 formulation was created to provide the optimal balance of nutrients to lawns as temperatures start to rise. In addition to nitrogen, Recover delivers critical micronutrients like soluble manganese, iron, sulfur and carbon, which help your St. Augustine get through the dog days of summer.

Each bottle of Lawnifi easily hooks right up to the end of your garden hose for an even spray application.

Option 2: The next recommendation we have is Lawnifi Foundation, a granular fertilizer option that comes in a 25-pound bag and feeds for three months. With a 29-0-5 NPK formulation, Lawnifi Foundation is the perfect granular fertilizer for lawns and gardens.

The two percent iron included in Lawnifi Foundation’s mixture helps plants carry oxygen throughout the leaves, roots and other parts of the plants to promote a green, healthy lawn.

Featuring slow-release nitrogen, Foundation gradually feeds your St. Augustine over an extended period of time without overwhelming your lawn with nitrogen during the summer.

Both Lawnifi Foundation and the Summer Fertilizer Box cover 5,000 sq. ft. Learn more in Granular vs. Liquid Fertilizers or by clicking on the two products below. For more generic information about the Lawnifi brand, read Why Use Lawnifi Fertilizer?.

3. Make Sure Your St. Augustine is Hydrated…But Not Too Hydrated

The summer season comes with significantly warmer temperatures and a longer amount of time with sunlight. This frequently tempts homeowners to water the lawn more often to make sure it’s hydrated. This is not always recommended as waterlogged soils in warm climates are ideal environments for disease outbreaks.

Despite the hot temperatures that occur during the summer, St. Augustine should only need about one inch of water on a weekly basis. This is best accomplished with one or two waterings a week.

Water in the early mornings for longer periods of time, less frequently and take any rainfall into consideration. Watering your lawn in the early morning decreases the dew period. As a result, this also decreases the amount of time the grass blades are wet, which is a helpful disease management practice.

If you aren’t sure how to measure one inch of water, consider conducting an easy irrigation audit. If the lawn seems to become too warm or starts accumulating scorched, brown spots, consider adding a layer of top dressing to keep it shaded and cool. Read more about this in How to Top Dress Your Lawn with Compost.

4. Be Cautious with Weed Control

The summer season is one of the worst seasons for herbicide applications on any type of turfgrass. When temperatures reach or exceed 85 degrees Fahrenheit, herbicide chemicals will damage the grass.

It’s best to wait until it gets cooler and apply a post-emergent herbicide to any weeds that are currently in your yard. In the future, apply a pre-emergent herbicide in the spring to reduce summer weeds and be sure to apply a pre-emergent herbicide in the fall to keep fall and winter weeds out.

If temperatures are consistently below 85 degrees, it’s generally safe to apply post-emergent herbicides for any summer annual and perennial weeds. However, we suggest waiting until it gets closer to the fall season. If temperatures are low one day and exceed 85 degrees in the following days, the grass is still vulnerable to damage from the herbicide.

Learn more in How to Control Weeds During the Summer.

A few common weeds you might see during the summer are knotweed, spurge, lespedeza, crabgrass, goosegrass, nutsedge and sandspur.

Pictured above from left to right: Knotweed, spurge, lespedeza, crabgrass, goosegrass, nutsedge and sandspur.

 Be sure to read herbicide labels thoroughly before application.

5. Watch Out for Insect Infestations or Damage

Insects can be a real nuisance in the summer. Bugs like fire ants or mosquitos aren’t the only ones to watch out for—there are a lot of insects that can cause severe damage to your lawn.

Some of the most common summer insects include chinch bugs, grub worms, mole crickets, fall armyworms and sod webworms.

Pictured above from left to right: A chinch bug, grub worm, mole cricket and sod webworm.

Symptoms of an insect invasion differs from insect to insect. For example, a common way to identify a grub worm problem is by noticing an increase in burrowing mammals like moles, that are feeding on them. You can also dig a little in your lawn and spot them that way.

June is about the time to apply a preventative insecticide for grub worms because the adult beetles like the Japanese beetle or May/June beetle start flying around and drop eggs at this time. Apply a systemic insecticide like Acelepryn to prevent grub worms.

Chinch bugs can also be bad around this time—especially in St. Augustine. Signs of a chinch bug infestation include a spotty pattern of patchy grass that almost looks like drought damage. If you know you have a chinch bug problem, apply Dylox 6.2 to knock them out quickly and reduce the amount of damage they can cause before problems get too severe.

Sod webworms, on the other hand, are known for munching on St. Augustine grass blades as opposed to the root system. They are little green worms that skeletonize the leaves on grass blades, leaving a windowpane look in the blade. 

Fall armyworms tend to leave the same kind of damage, but they are either green or a muddy brown with a wide, horizontal black stripe running down each of their sides. They are around 1–1.5 inches in length and have a lightly colored upside-down “Y” that marks the head of the worm. 

Lastly, a mole cricket infestation can be identified by their tunnels which push up soil and grass, as well as the presence of brown and dying grass due to mole cricket feeding habits.

Some of the insect control products listed below are labeled to treat these common insects. Be sure to read the label thoroughly before application. Learn more about different types of lawn insects in Insect Identification.

6. Relax About Disease Control

Disease outbreaks in St. Augustine lawns are pretty uncommon at this time, however, they can still happen—especially if you overwater your lawn during the summer. The most common of them in St. Augustine at this time are gray leaf spot which occurs when conditions are warm and wet.

Pictured above: Grey leaf spot in St. Augustine grass.

Although certain chemical solutions found in fungicides have the ability to cure lawn disease, there are a few cultural methods you can perform to keep disease outbreaks from occurring beforehand. These cultural methods are common maintenance practices found in our St. Augustine Homeowner Maintenance Guide. Overtime, these maintenance practices promote a healthy lawn that can withstand stressors and fight off things like insects or disease.

However, there are a few recommended disease control products we’ve listed below. Be sure to read the label thoroughly before application. You can learn more about these diseases in Identifying Common Lawn Diseases.

Summer lawn care tips for your St. Augustine lawn are mostly about keeping it healthy and stress-free during the hot summer temperatures. This will help it continue to thrive when temperatures eventually cool down and we enter into the fall season. We will see you back here in the fall for our updated fall maintenance tips for St. Augustine.

And remember…if you want lawn care made simple, the Lawnifi Complete Subscription provides your lawn with what it needs during the current season and for years to come.