Best Weed And Feed For St Augustine Grass: St. Augustine is a turfgrass that can create a lush green lawn especially in warmer coastal areas suc… St. Augustinegrass (Stenotaphrum secundatum), sometimes referred to as Charleston grass, is a coarse-textured, spreading grass that is popular throughout… The best weed and feed for St. Augustine grass lawns is Scotts Southern Tripple Action Turf Builder. Alternative products you can also use are Spectracide Weed and Feed, Pennington Ultragreen Southern Weed and Feed and Ferti-Lome Weed and Feed. I’ve reviewed them below in detail.
8 Best Weed And Feed For St Augustine Grass In Florida 2022
Best Weed And Feed For St Augustine Grass: St. Augustine is a turfgrass that can create a lush green lawn, especially in warmer coastal areas such as Florida and the Carolinas as well as Southern California. However, it needs some amount of care which is one of the crucial factors to keep in mind when it comes to managing the St Augustine lawn is fertilization.
The fertilizers for feed and weeds don’t just provide fertilization but also weed killers. It’s 2 for the cost (and time) that of just one.
8 Best Weed And Feed For St Augustine Grass In 2022
Table of Contents
Here are the top 8 herbicides and fertilizers specifically designed to maintain St Augustine lawns.
Scotts Snap Pac Weed and Feed – 12.8 lb, Builds Strong, Deep Roots, Kills Dandelions, White Clover, Chickweed, Ragweed and More, Covers up to 4,000 sq. ft.
BioAdvanced 3 in 1 Weed and Feed and Feed for Southern 5M Lawn Fertilizer with Herbicide, 12.5 lb, Granules
Scotts Turf Builder Southern Triple Action – Kills Dollarweed and Clover, Prevents and Kills Fire Ants, Feeds and Strengthens Lawns – Covers up to 4,000 sq. ft.
1. Pennington Ultragreen Southern Weed And Feed
The best products for special needs are usually superior to general products for lawn maintenance. This is particularly relevant when dealing with St. Augustine grass, which requires a different type of care and doesn’t work with other popular products.
Pennington’s southern blend contains 22.1 per cent nitrogen in the slow-release form. This is quite high for products for weeds and feeds as well as helps to control the growth of weeds for three months. It is a summer weed as well as feed, it’s perfect to control weeds once they grow on lawns with established turf which is why it’s great to maintain your grass cover.
Why We Like It
- Provides excellent Summer control
- It is possible to put off applying it until you’re sure that you’ll require it.
- It contains iron to fortify lawns
Overall, it’s an excellent product and should be starting your search for a feed and weed. The iron enrichment is a wonderful feature for lawns, but the summer application means you could want to buy and make use of it even if purchase a different fertilizer for the spring. Many stores sell it at a very competitive price as well, which makes it easier to be incorporated into a typical budget for garden maintenance.
Editor’s Rating: 5/5
2. Sunniland St. Augustine Weed And Feed
In many ways, it’s the opposite of our first selection. Sunniland’s mix can be used in all seasons other than the summer months and has a slow-release mix that can control the plants up to 90 days in a stretch. It is also free of Phosphates, which is more suitable for waterways in the local area and is one of the reasons why we chose to position it on the top of this list.
The product is focused exclusively on St. Augustine almost to the exclusion of other grasses. If you’re planning to seed it, you’ll have to wait 8 weeks which is fairly long but not the most difficult we’ve ever seen in the past for planting.
- A special design specifically made specifically for St. Augustine grass
- Useful throughout the year.
- There aren’t any Phosphates
This is a fantastic product in general and a great complement to our number one selection. If you are looking to fertilize your lawn throughout the year These two products give you the coverage and control lawns require.
The only issue with the product would be that manufacturers typically offer it only in bags that measure 5,000 square feet which means you’ll have to purchase multiple bags to cover a larger space.
Editor’s Rating: 5/5
3. Sta-Green Weed and Feed
Sta-Green’s Weed & Feed blend is among the most versatile and multi-functional products available that can be used on almost any type of grass, while also offering excellent pest control. Apart from helping to eliminate more than 250 kinds of weeds which are one of the most you’ll see in a weed-feed product, it can also help to protect against the more severe winter weather.
But, this power isn’t without a disadvantage. It’s winterized which helps prepare St. Augustine grass for spring growth, but it’s not very effective when you apply it beyond the autumn. This makes it an inferior option to control weeds during St. Augustine’s growth season, nevertheless, it’s a great product to help strengthen your lawn.
- Competitive pricing
- Supports deep root systems
- Are things different in Summer and Spring? fertilizers aren’t
This product for weeds and feed is the best choice when you need to build and maintain your lawn. It’s not as effective for lawns that are fully established however, you might want to apply it if you experience harsh winters and wish to safeguard your lawn to the greatest extent possible.
Editor’s Rating: 4.5/5
4. Scotts Snap Pac Weed and Feed
Scotts is among the most well-known manufacturers and their track record shows through their options such as their feed and weed Snap Pac. This is a brand new product created for Scotts its exclusive Snap Spreader System. You’ll have to purchase that separately if you intend to utilize this fertilizer, however, since Snap Pacs can automatically adjust the spreader to the correct setting this removes the confusion and adjustments from the procedure.
Each bag can cover four thousand square feet of grass. That may be a bit lower than average and is one reason why this product is not on our list.
- It is easy to use using the correct spreader
- Effective in both the Spring and Autumn.
- Perfect for people who aren’t experienced with fertilization
It is worth noting that the Snap Pac is more expensive than the other options for feed and weed control that we have reviewed, however its outstanding weed control capabilities and simplicity of use place it in a league that is its own. If you’ve got a smaller lawn and would like to reduce the frequency of fertilization This is a great product, to begin with.
Our Verdict: 4/5
5. BioAdvanced 3 in 1 Weed and Feed for Southern Lawns
BioAdvanced does not have a lot of products to choose from however their three-in-one blend is a great choice for feeding St. Augustine lawns while managing various weeds, including crabgrass. The time frame for fertilizer application is a bit short with only two months however, the weed control can last for as long as 6 months. This is great when your lawn is established.
It is important to only purchase your Southern Lawns bag. BioAdvanced has several similar products, but they aren’t suitable to be used on St. Augustine grass and can cause harm to your lawn if you make use of these products.
Why We Like It
- Highly efficient formula
- More protection for weeds overtime over competitors
- Content of high nitrogen
This is among the most effective alternatives for feeding and weed control to use on St. Augustine lawns. Its cost is in the middle of the weed and feed options with its high-efficiency formula work well in removing the growth of weeds. We suggest this product when your soil is generally well-groomed, yet you require to manage weeds for a long period, to ensure that your lawn will develop better.
It’s most effective during the summer and spring So, you should consider a winterizer such as our top choice, #3 from Sta-Green.
Editor’s Rating: 4.5/5
6. Scotts Turf Builder Southern Triple Action
Scotts was likely to make it included on this list at minimum twice, regardless of what we tried however, the Southern Triple Action bag is worthy of consideration for anyone looking to purchase. It is not only effective in killing all kinds of weeds in addition to providing nutrients to St. Augustine lawns, this mix additionally helps to keep common pests such as grasshoppers, fire ants, ticks and fleas from settling in the region.
The protection against insects is long-lasting also and the protection lasts for six months if this product is used correctly. Some fertilizers do not stop insect pests, therefore if insects are an issue in your region you should consider this product first.
What We Like
- Long-term effectiveness
- Allows multiple treatments if needed.
- Minimal waiting time if planting seeds
The ability to kill insects is the main selling point of this weed as well as feed. It’s an uncommon quality and was an important factor in our choice to include this product in our list of recommendations. Scotts sells this product in four thousand and eight hundred square feet that are different from what is standard in the market but is still suitable for the majority of homeowners.
Southern Triple Action Southern Triple Action formula is higher priced than the majority of alternatives However, if you’re using it to improve the quality of your lawn and stop insect infestations, we believe it’s well worth the cost.
Editor’s Rating: 4.5/5
7. Spectracide Weed & Feed
Its Weed & Feed is a low-cost liquid that requires a hose as well as the ability to walk at a consistent speed. Each bottle can treat up to 7500 sq ft of lawn, but the actual amount varies depending on the speed at which you walk. This blend concentrates on controlling broadleaf weeds, and might not be as effective against other types of pests and harmful plants.
- Easy to use
- It covers a vast area for the cost
- Ideal for supporting lawns with established borders.
Feed and weed options are the most effective to provide long-term stability that lawns in the process of growing need. Liquid fertilizers such as this are used to maintain lawns that don’t need more external support. That’s why we aren’t able to recommend it to anyone despite its price and user-friendly.
If, however, your lawn requires only some care to remain well-groomed, liquid fertilizers like these are some of the top alternatives available.
Editor’s Rating: 4.5/5
8. Sta-Green Ready-to-Spray Weed and Feed
Another liquid fertilizer, Sta-Green’s formula can be used for nearly all types of grass and has 20% nitrogen, which is excellent for control of weeds. Similar to other liquid products they cover around 7,500 square feet. It is extremely simple to use as it is the hose that is long enough to cover the entire garden.
Sta-Green suggests using this product anytime the weeds are in full bloom. However, they recommend applying a heavy watering regimen for 1 to 2 days before applying the product, which will require more planning than much other weed and feed products.
- Extremely simple to make use of
- Ideal for southern grasses like St. Augustine
- Effective on most broadleaf weeds
It’s a great alternative to liquid fertilizer that’s somewhat more expensive than the one we recommended previously. At only 20 minutes per bottle, it’s an efficient and simple method to feed lawns when required. We see this as an aid rather than an all-purpose weed and feed mix. It is better suited for lawns that are established as opposed to those still growing.
But be aware that this mix does not include any Potassium or Iron in it. If you need to adjust your soil to a greater extent then you can consider using a different herbicide and feeding instead of this one.
Editor’s Rating: 4.5/5
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How Aggressive Should I Be About Weeding And Feeding St. Augustine?
Short answer: Read the directions.
In general, you’ll need to apply weeds and feed in the springtime, especially when it’s the use of a pre-emergent herbicide. Pre-emergents stop weeds from growing thus, even though they will take charge of an abundance of weeds, they will not assist with the winter weeds already in the area. If it’s a herbicide that is post-emergent it is recommended to fertilize your garden in the late spring or throughout the entire year according to the climate of your area.
How Aggressive Should I Be About Weeding And Feeding St. Augustine?
You must be very assertive when St. Augustine is building its sod layer. Removing weeds to their roots will allow St. Augustine to build the strongest possible defence for it. After it’s established, it will require maintenance but not as often.
Fertilizer is among the things that more is not necessarily better. If you apply too much of it, you might notice the lawn turning yellow which is usually caused by nitrogen burn.
What’s St Augustine grass?
St. Augustine is a grass that grows in warm weather commonly used to create lawns as well as pastures and other vast areas. While it is a strong fan of warm climates and is found throughout the southern part of the United States, it can be tolerant of colder coastal areas that experience mild winters.
St. Augustine grass is extremely valuable due to its thick sod, which assists in eliminating the other grasses and weeds that give an even appearance. However, getting the grass up to this level requires care and attention during its initial growth stages, and after that owners can shift to maintaining the grass. Although St Augustine is most common in states such as Florida It can be grown in a variety of southern climates, assuming that the soil type is appropriate.
It thrives in soil that has a pH between 5 to 8.5 Which is more than most of its rivals. If you’re planning to grow St. Augustine, be sure to examine the soil of the area you live in to determine if the grass is a good match for your soil. You may need to alter the soil before adding grass.
St Augustine grass lawns are extremely lush. They require regular cutting (never cutting more than 1/3 of the length of the blade) using razor-sharpened blades .
The place where is St Augustine grass-grown?
If you own a St. Augustine grass lawn there’s likely a possibility that you live in Florida which is the ideal environment that is ideal for St Augustine. However, the grass is a great choice for the coastal Carolinas and the Gulf Coast and southern California. It’s anywhere that’s warm all year and has water nearby.
Are you interested in learning more? St Augustine Services?
A healthy lawn with beautiful green colours isn’t easy, and the methods applied depend on the type of grass. For more information regarding St Augustine’s care, we suggest the following video by Franklin Hernandez.
Can you feed St. Augustine with Scotts weed?
For example, Scotts Turf Builder Feed and Weed should not be mixed with St. Augustine grass even though the Turf Maker with Halts Crabgrass Preventer can be used safely.
Is atrazine found in Scotts weed or Feed?
It contains an herbicide called atrazine . This herbicide is toxic and should not be used around shrubs or trees.
How often should your lawn be weeded and fed?
Do not apply weed or feed products more often than once a year . It’s okay to apply another spring application if your spring application has not resolved your weed problem. Two months should be allowed between applications.
What time should I apply weedkiller to my lawn?
Gardeners should apply weed killer in the spring to get the best results. To combat invasive weeds such as crabgrass, gardeners usually reapply the herbicide eight weeks after the initial spray.
This Pennington Ultragreen Southern Weed and Feed mix is a suitable option to use for St. Augustine lawns. You can put off using it until you are sure that you will need it every year. Additionally, the iron can be a great way to enrich your lawn as well as establish sod.
Scotts Turf Builder Southern Triple Action formula is quite expensive, however, its insect repellent properties are not common in the world of weeds and feed and are worth the cost if you want to safeguard your home from invasion. It is recommended to hire an expert to determine which pests are threatening your home before purchasing any feed or weed.
Its Sta-Green Ready-to-Spray Weed and Fertilize is affordable, even for an extremely tight budget for gardening. Although it’s not as efficient as other solid fertilizers, however, it’s a great option for maintaining St. Augustine lawns that already have their sod layer completely installed.
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St. Augustinegrass Yearly Maintenance Program
St. Augustinegrass (Stenotaphrum secundatum), sometimes referred to as Charleston grass, is a coarse-textured, spreading grass that is popular throughout warmer regions of the Southern United States. It will turn brown with fall freezes and will be slow to green in the spring. It is the least cold tolerant of the warm-season turfgrasses. See HGIC 1211, St. Augustinegrass for additional information on care and cultivar selection.
St. Augustinegrass is a wide-bladed, spreading, warm-season turfgrass that is adapted to the warmer regions of the southeastern United States.
Joey Williamson, ©2018 HGIC, Clemson Extension
Producing a yearly maintenance calendar for managing turfgrass consistently year after year can be difficult in a state with such a diverse climate as South Carolina. Therefore, it is important to monitor temperatures and apply the needed management practices based on that year’s climate. Important times to monitor the weather are during late winter or early spring when the turf is coming out of dormancy and early autumn when the first frost is forecasted. Last frost dates and first frost dates can vary by several weeks from the coastal areas of South Carolina to the foothills of the Upstate.
This turfgrass maintenance calendar may be used on turf grown throughout the state; however, management practices may need to be adjusted based on the year’s climate and the region where the turf is grown.
January through April
Mowing: Mow the lawn slightly lower than the regular summer mowing height. The mower setting should be between 2 to 2½ inches high. Be careful not to set the mower too low, as it may scalp the lawn. This height reduction should be done just before the lawn greens up, which usually occurs during late April or early May. If possible, use a mower with a bagger to collect the clippings and remove the dead material left from winter dormancy. Be sure to use a sharpened mower blade. Alternatively, the lawn can be hand raked to remove the excessive dead leaf material from the lawn surface.
A sharp mower blade will cleanly cut the grass blades as opposed to tearing the leaves. Dull mower blades rip rather than cut the grass and make the grass more susceptible to diseases. Sharpen the mower blade monthly or as needed during the growing season.
A dull mower blade will shred the turfgrass foliage.
Gary Forrester, ©2018, Horticulture Extension Agent, Clemson University
The date of initial turf green-up can be quite variable. In the coastal and more Southern regions of South Carolina, this generally will occur sometime during April, but further inland, this may be as late as mid-May. It is not unusual for St. Augustinegrass to green up and be burnt back several times during the late winter or early spring due to late season frosts. For more information on mowing, refer to HGIC 1205, Mowing Lawns.
Thatch Removal: If a thatch layer becomes a problem, use a dethatcher or vertical mower to remove it. For St. Augustinegrass, consider dethatching when the thatch layer is greater than ½ inch. For best results, use a dethatcher with a 2- or 3-inch blade spacing set at a ¼-inch depth after the turf has fully greened-up. Do not use a power rake with a 1-inch blade spacing, as severe turf injury may result. Use a lawn mower with a bag attached or hand rake to collect and properly dispose of the turf material pulled up. For more information on thatch removal, see HGIC 2360, Controlling Thatch In Lawns.
Aerification: Core aeration is the process of punching small holes into the turf and soil to alleviate compaction, allowing air to get to the root system. This will help to correct problems associated with poor infiltration and drainage. Once the threat for spring frost has passed and the lawn is fully greened-up, lawn aerification may be combined with dethatching to alleviate soil compaction and thatch problems.
However, if a pre-emergent herbicide was applied late February to mid-March, postpone any cultivation practices that will disturb the soil until just before the next pre-emergent herbicide application date. Pre-emergent herbicides create a barrier that keep weed seeds from germinating. Disturbing the soil after an application will allow weeds to emerge through this barrier. For more information on aerification, see HGIC 1226, Turfgrass Cultivation and HGIC, 1200 Aerating Lawns.
Weed Control: To control crabgrass, goosegrass, sandspurs, and other summer annual weeds, apply a pre-emergent herbicide early in the year. Approximate application times are mid-February in the coastal and central areas and mid-March in the piedmont/mountain areas. A second application is needed approximately 8 to 10 weeks after the initial application to give season long control of annual warm-season weeds.
Apply a post-emergent herbicide as needed to control existing winter weeds. In general, do not apply post-emergent herbicides to the lawn once the turf begins to green. If a weed problem begins and the grass has begun to green with warmer temperatures, wait until the grass has fully greened-up before applying a post-emergent herbicide. In the meantime, mow and bag the weeds. St. Augustinegrass is sensitive to certain herbicides, such as 2,4-D, not only during spring green-up, but also during hot summer temperatures. Follow label directions for use of any herbicide and use with caution during these times. For more information on weed control, see HGIC 2310, Managing Weeds in Warm-Season Lawns.
Insect Control: Cold winter temperatures will help usually keep insect problems at bay. As temperatures start to warm in late spring, monitor for mole cricket and chinch bug activity. If either insect is observed, apply a lawn insecticide when damage becomes excessive. If the damage is minimal, monitor the activity and wait before applying an insecticide. This is not the best time to apply an insecticide because of the cool soil temperatures and reduced insect activity. However, an early spring warm-up can lead to both mole cricket and chinch bug activity. Heavy populations can be reduced with appropriately timed insecticide treatments during this period. For more information on mole cricket or chinch bug control, see HGIC 2155, Mole Cricket Management in Turfgrass or HGIC 2487, Chinch Bugs.
If grubs (the white larvae of beetles, such as Japanese beetles) have been a problem in previous years, monitor them by cutting a square foot piece of sod on three sides and peeling it back. If more than six grubs are found under the sod piece, apply a lawn insecticide labeled for grub control according to label directions. For more information on white grub management, see HGIC 2156, White Grub Management in Turfgrass.
Fertilization: Fertilization of St. Augustinegrass should be based on soil test results, and this is a good time to test soil. However, fertilizers containing nitrogen should not be applied during this period. If new turfgrass growth is encouraged by fertilization during the early spring, and it is followed by a late frost, this can result in significant damage to the lawn. See HGIC 1652, Soil Testing for instructions on how to properly submit a soil sample.
Irrigation: During dormancy, water the lawn to prevent excessive dehydration. Winter desiccation can be a problem during dry winters. Watering to prevent drought stress can help eliminate turf loss during the winter.
Most areas of South Carolina receive enough rainfall during the winter to avoid winter desiccation of lawns. However, this is not always the case. Monitor the winter rainfall on a regular basis, and apply water to the turf if no measurable rain occurs over a 3 to 4 week period. This is especially important if warm, bright days preceed days forecasted to be in the low 20’s or colder. The added moisture in the soil will help keep the growing points of the turf warmer, preventing crown death.
To manage a lawn, it is important to know the soil texture in the top foot of soil. Sandy soils do not hold moisture well since they drain freely and dry out quicker. Clay soils, however, will hold moisture for a longer period of time. Be sure to not allow the lawn to stay excessively wet if the lawn has a clay soil. If the soil stays saturated all winter, this can cause many other problems. A soil probe can be used to monitor soil moisture. For more information, refer to HGIC 1207, Watering Lawns and HGIC 1225, Conservative Turfgrass Irrigation.
May Through August
Mowing: The ideal mowing height for St. Augustinegrass can range from 2½ to 4 inches depending on the specific site and management regime and is best determined by the growing conditions. Lawns in shady areas perform better when mowed at 3 to 4 inches high.
During periods of environmental stress due to high temperatures or a lack of rainfall, raise the mowing height ½ to 1 inch until the stress is eliminated. Always mow with a sharp blade using a mulching type mower, which leaves the clippings to decompose on the turf. The mower blade needs to be sharpened on a regular basis – usually about once a month or at least before the growing season starts. If the bag is picking up soil, mainly sand, when the lawn is mowed, then the blade may need to be sharpened more often than once a month.
Fertilization: Always fertilize and add lime or sulfur based on a soil test. St. Augustinegrass will grow best at a pH of 6 to 6.5. If a soil test indicates a higher soil pH, sulfur can be applied to lower it. Apply 5 lbs of pelletized sulfur per 1000 square feet of turf. Apply sulfur only when the air temperatures are below 75°F. In 3 months, recheck the soil pH and see what change was made. It may take several years to make a large pH change. Soils in the upstate are typically acidic and rarely need sulfur applications but usually do need lime.
St. Augustinegrass lawns should receive 2 to 4 pounds of actual nitrogen per growing season, per 1000 square feet of turf. The higher rate may be chosen for those growing St. Augustinegrass on sandy soils with the lower rate for those lawns growing on clay soils. An application of a soluble iron product, such as iron sulfate or a commercial chelated iron, in between fertilizer applications, will enhance the green color without encouraging growth. St. Augustinegrass should be fertilized three times during the summer, as recommended below. However, in the piedmont and midlands of SC where the turf is growing on clay soils, St. Augustinegrass is typically fertilized only twice during the growing season (early May and early July).
Early Summer (May): Apply ½ to 1 pound of actual nitrogen per 1,000 square feet in early May after the lawn fully greens up. The rate will depend on soil type. A soil test will help determine if a fertilizer containing phosphorous is required. See the section on fertilizer calculations below to determine how much granular fertilizer should be applied.
Mid-summer (June through July): Fertilize with ½ to 1 pound of actual nitrogen per 1,000 square feet, depending on soil type, using a high potassium fertilizer such as 15-0-15. This fertilizer may be especially important if the soils are sandy. The addition of phosphorous, the middle number in the fertilizer analysis, should only be applied if recommended by a soil test.
Late Summer (August): Fertilize with ½ to 1 pound of actual nitrogen per 1,000 square feet, depending on soil type, before August 15 using a high potassium fertilizer such as 15-0-15. The addition of phosphorous, the middle number in the fertilizer analysis, will need to be determined by a soil test. Potassium is needed late in the growing season as the grass goes into dormancy for added disease protection and winter hardiness.
Nutrient Deficiencies: A yellow appearance during the growing season may indicate an iron deficiency due to excessive phosphorus and/or a high soil pH. A long-term approach is needed to correct either cause, but an iron product can be added to quickly enhance turf color between the spring and summer fertilizer applications.
NOTE: A yellow appearance may also develop during early spring. This could indicate an iron or manganese deficiency due to soil temperatures lagging behind air temperatures, high pH soils, or high phosphorous levels. Spraying with liquid iron (ferrous sulfate) at 2 ounces in 3 to 5 gallons of water per 1,000 square feet or applying a chelated iron product will help to enhance turf color. Fertilizing with a micronutrient fertilizer, such as manganese sulfate, can alleviate manganese deficiencies. However, as the soil temperatures start to climb, the yellowing should slowly go away. Lime or sulfur may also be added if a soil test indicates a need. Be aware, it could take several months for lime and sulfur applications to affect the soil pH.
Fertilizer Calculations: To determine the amount of granular fertilizer needed to apply ½ pound of actual nitrogen per 1,000 square feet, divide 50 by the first number on the fertilizer bag. To determine the amount of product required to apply 1 pound of actual nitrogen per 1,000 square feet, divide 100 by the first number on the fertilizer bag. This will give the number of pounds of product to apply to 1000 square feet of turf. See HGIC 1201, Fertilizing Lawns for more information.
Irrigation: Water the lawn to prevent drought stress. Monitor the lawn on a regular basis to assess the need for irrigation. When the entire lawn appears dry, apply ¾ to 1 inch of water the next morning. Wait to irrigate again until the lawn shows moisture stress. There are several ways to determine when the lawn needs watering. One way is to observe the lawn daily. When the turf begins to dry, it will appear to have a bluish hue. Another method is to walk across the lawn late in the evening. If the grass blades in the footprints bounce back up, then there is plenty of moisture in the turf. If the grass in the footprints does not bounce back, then irrigate the lawn the next morning.
The irrigation interval will vary from site to site depending on the environmental conditions at that site and soil type. The general rule to turfgrass irrigation is to water “deeply and infrequently”. Localized dry spots or hot spots can be watered as needed by hand. The irrigation system should only be run when the entire lawn is dry. For more information on turfgrass watering, see fact sheet HGIC 1225, Conservative Turfgrass Irrigation.
Insect Control: There are various insects and related pests that may infest St. Augustinegrass during the summer months. Mole crickets, chinch bugs, spittlebugs, grubs, ground pearls, and nematodes can cause considerable damage. Each pest problem has its own management strategy and is usually handled with cultural and chemical controls. However, there can be exceptions. Mole crickets and grub eggs will usually hatch mid-summer. Insecticide applications targeted at the mole crickets in their smaller nymph stage are the most effective controls, even if damage has not yet occurred. If either of these insects was a problem early in the season, apply an insecticide during mid-July to control the younger immature insects.
Chinch bugs can be very destructive to St. Augustinegrass. Monitor the turf on a regular basis during the growing season, especially during hot, dry periods. Damage is often more severe in sunny areas near driveways, sidewalks, or roadways, where the turfgrass is under more heat stress. A chinch bug is a small black insect with silver wings that sucks plant juices from the stem. An infestation may cause the turf to die, which will need to be replaced or allowed to grow back in.
Chinch bugs are fairly easy to control using general insecticides, but applications need to be made before the population has risen to a level where damage is occurring. Research has shown that an early season insecticide application after the turfgrass has greened-up will reduce the late season activity. When applying insecticides for chinch bug control during the summer, rotate chemical families or mode of actions to reduce the chance of pesticide resistance.
Disease Control: The most common diseases that affect St. Augustinegrass during the growing season are large patch (formerly known as brown patch) and gray leaf spot. Large patch is a fungal disease that is active during warm, humid spring and fall weather. Since it is fueled by moisture, it is important to maintain a rather dry condition in the lawn by employing proper watering practices, as well as providing adequate soil drainage.
If the turf stays wet, circular yellow to brown areas may begin to develop and slowly grow in size. Later, the center of the circle may start to re-green. In heavily infested turf, the rounded areas may grow together and no longer appear circular. If the turf at the edge of the dying area shows a smoky brown, rotted appearance, it will be necessary to apply a fungicide treatment. For more information, please see HGIC 2150, Brown Patch & Large Patch Diseases of Lawns.
Gray leaf spot may occur on St. Augustinegrass during the heat of summer when the turf remains damp for extended periods, usually during rainy periods or on newly laid sod being kept wet. There will be small purplish spots on the leaves and at an advanced stage, the grass will have a scorched appearance. At this point, a fungicide application will be needed. Please see HGIC 2151, Gray Leaf Spot on St. Augustinegrass.
Overall, proper water management, fertilization, mowing height, and thatch control are essential to curtail large patch and gray leaf spot problems. To help reduce disease problems, fertilize and lime St. Augustinegrass according to a recent soil test report.
Weed Control: A selective, annual grass and/or broadleaf weed control pre-emergent herbicide that is labeled for use on St. Augustinegrass and applied during late winter and spring will reduce many weeds the following summer. If a pre-emergent herbicide was not applied in the spring, the resulting weeds will need to be controlled using postemergent herbicides.
Summer weeds, such as spurge and annual lespedeza can be managed by using a post-emergent herbicide for broadleaf weeds sometimes referred to as a 3-way mix. Three-way herbicides typically contain 2,4-D. St. Augustinegrass is sensitive to 2,4-D, so follow label directions for mixing and use. Do not apply herbicides unless grass and weeds are actively growing and are not suffering from drought or heat stress; therefore, water the lawn thoroughly the day before application. Additionally, do not apply post-emergence herbicides when the turf is emerging from winter dormancy or when the summer temperatures are 90 °F or higher. Do not mow the lawn 3 days prior or 2 days after application. As with all pest control, proper weed identification is essential for best control options. Contact the local County Extension Office or the Clemson Home & Garden Information Center for identification and control of weeds in the lawn. For more information on weed control, see HGIC 2310, Managing Weeds in Warm Season Lawns.
Renovation: Replant large bare areas in May using sod, plugs, or sprigs (5 bushels per 1,000 square feet). For more information, refer to HGIC 1204, Lawn Renovation.
September through December
Mowing: Continue to mow St. Augustinegrass at the normal mowing height until the weather starts to cool in the fall. Once nighttime temperatures fall below 70 °F, raise the mower cutting height ½ to 1 inch to allow more leaf surface. This will allow the turf to become acclimated by the time the first frost occurs.
Fertilization: Do not apply nitrogen at this time. Lime or sulfur may be applied if recommended by a recent soil test. Potassium, typically known as potash, may be applied to enhance winter hardiness if a recent soil test indicates low to medium levels of potassium. Apply 1 pound of potash (K2O) per 1,000 square feet, 4 to 6 weeks before the first expected frost, using 1.6 pounds of muriate of potash (0-0-60) or 2 pounds of potassium sulfate (0-0-50) per 1000 square feet.
Irrigation: In the absence of rainfall, continue to water to prevent drought stress. After the lawn has become dormant, water as needed to prevent excessive dehydration. This is especially important if warm, bright days proceed days forecasted to be in the low 20’s or below.
Insect Control: Any insects that were missed during the nymphal stage in the summer will have grown to a size where turfgrass damage is occurring. Apply an insecticide to reduce the population and reduce further turf damage. This is best done before the first frost.
Disease Control: For disease control, especially large patch, it is extremely important to treat with fungicides during the fall months. With warm temperatures through September and the possibility of excessive rainfall that may occur during that period, diseases can increase rapidly. However, with cooler nights and shorter day lengths, control can be quite difficult because of slow turf recovery during this time. Turf weakened by disease in fall will be slow to recover in the spring; therefore, fungicide applications are needed to control disease before the grass goes dormant. In certain situations where large patch has been prevalent yearly, a preventative fungicide application may be needed starting in early October to stay ahead of the disease. For more information on disease control, please see HGIC 2150, Brown Patch & Large Patch Diseases of Lawns.
Weed Control: Many winter annual weeds can be managed by applying a pre-emergent herbicide in September with a second application 8 to 10 weeks later. Follow all label directions on the product for application rate. Granular herbicides must be watered into the soil soon after application. Follow label directions as to post application watering.
Selective, post-emergent herbicides can be applied as necessary for control of chickweed, henbit, and other cool-season broadleaf weeds. St. Augustinegrass is sensitive to certain herbicides, such as 2,4-D, so follow label directions for reduced mixing rates. Spray sufficiently to wet the foliage, but do not spray excessively. Repeat application in 10 to 14 days, if needed. Selective herbicides may be applied in the winter for control of annual bluegrass and other winter annual weeds. For more information on weed control, see HGIC 2310, Managing Weeds in Warm Season Lawns. Contact the local County Extension office or the Clemson Home & Garden Information Center for weed identification and control measures.
Originally published 09/05
If this document didn’t answer your questions, please contact HGIC at [email protected] or 1-888-656-9988.
Trent C. Hale, PhD, Former Extension Turfgrass Specialist, Clemson University
Chuck Burgess, Former HGIC Horticulture Extension Agent, Clemson University
Gary Forrester, Horticulture Extension Agent, Horry County Extension Service, Clemson University
This information is supplied with the understanding that no discrimination is intended and no endorsement of brand names or registered trademarks by the Clemson University Cooperative Extension Service is implied, nor is any discrimination intended by the exclusion of products or manufacturers not named. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed.
Best Weed and Feed for St. Augustine Grass
When choosing weed-and-feed products for your lawn, you’ve got to be careful as some herbicide additives can have side effects on different turfgrasses. I always want to check the active ingredient and the NPK ratio to make sure they’re safe and appropriate for St. Augustine grass and the type of weeds I’m targeting.
The best weed and feed for St. Augustine grass lawns is Scotts Southern Tripple Action Turf Builder. Alternative products you can also use are Spectracide Weed and Feed, Pennington Ultragreen Southern Weed and Feed, and Ferti-Lome Weed and Feed. I’ve reviewed them below in detail.
Best Weed and Feed for St. Augustine Grass
Weed and feed products comprise mineral ingredients that add nutrients to the soil as well as systemic or contact herbicides that kill weeds on your lawn. They’re available in either granular or liquid form.
- It`s 29:0:10 NPK fertilizer.
- An insecticide.
- Kills dandelions, chickweed, and dollarweed.
- 15:0:4 NPK fertilizer
- Contains zinc and iron.
- Controls crabgrass, sedge, spotted spurge.
- 2, 4-D dimethylamine salt.
- Dichlorprop-p dimethylamine salt.
- Mecoprop-p dimethylamine salt.
- It`s a 20:0:6 NPK fertilizer.
- Kills a wide range of weeds like crabgrass and spurge.
- 34:0:4 NPK fertilizer
- Kills henbit and clover in lawns
- Has 5% iron that makes grass greener
- Kills 200+ broadleaf weeds.
- Fast action in 2 days.
- Systemically kills weeds to the root.
- Kills up to 250 weeds.
- Safe for St. Augustine grass.
- 26:0:12 NPK fertilizer.
The best weed and feed products for St. Augustine lawns are those that effectively get rid of weeds while simultaneously boosting St. Augustine turf growth.
Below, we detail some of the best weed and feed products, factoring in various benefits like the versatility of use, affordability, NPK ratio, and potency.
1. Scotts Southern Triple Action Turf Builder
- It is a 29:0:10 NPK fertilizer.
- It acts as an insecticide for your lawn.
- Kills dandelions, chickweed, and dollarweed.
Scotts Tripple Action weed and feed contains Atrazine, a herbicide that effectively gets rid of stubborn turf weeds like dandelions, dollarweed, and chickweed. It also infuses your lawn with nutrients that boost the turf’s capacity to withstand heat and drought.
Scott’s Turf Builder Southern Triple Action weed and feed is a 3-in-1 product that also contains Bifenthrin, an insecticide that kills common St. Augustine lawn pests like fire ants and chinch bugs. I found that it is best applied on St. Augustine grass after the third mowing of the growing season and shouldn’t be used during winter dormancy.
2. Ferti-Lome St. Augustine Weed and Feed
- 15:0:4 NPK fertilizer
- Controls crabgrass, sedge, spotted spurge, etc. in lawns
- Contains zinc and iron that green up your lawn.
Ferti-Lome St. Augustine Weed and Feed are specially formulated to get rid of common St. Augustine lawn weeds like Paspalum and Crabgrass. It works well as both a pre-emergent and post-emergent herbicide. This herbicide-cum-fertilizer has a 15:0:4 NPK ratio.
Ferti-Lome comprises 0.79% Atrazine, a potent herbicide that effectively kills several types of warm-season turf grass weeds. This weed and feed product is also laden with micro-nutrients like iron, zinc, and boron.
Take note though, that Ferti-Lome St. Augustine Weed and Feed is only half as powerful as Scott’s Southern Triple Action Turf Builder.
3. Spectracide Weed and Feed
Spectracide Weed and Feed is a ready-to-spray lawn treatment with an NPK ratio of 20:0:0. It consists of the following active ingredients:
- 2, 4-D dimethylamine salt- an auxin-type herbicide that effectively eradicates broadleaf weeds without affecting St. Augustine grass.
- Dichlorprop-p dimethylamine salt- a post-emergence herbicide that’s effective in controlling brush weeds like dandelion and clover.
- Mecoprop-p dimethylamine salt- a common broadleaf weed controller.
Depending on how healthy your St. Augustine lawn is, it may take a repeat application to completely get rid of clover and dandelion weeds from your lawn using Spectracide Weed and Feed.
You may also have to be patient, as the product may take up to four weeks to fully get rid of weeds, factoring in the turf conditions.
4. Sunniland St. Augustine Weed and Feed
It is a 20:0:6 NPK fertilizer
Sunniland St. Augustine Weed and Feed is an excellent choice for St. Augustine turfs because it can be applied both in the spring and in the fall. With an NPK ratio of 20:0:6, this weed and feed formulation for St. Augustine grass infuses lawn soil with ample amounts of nitrogen and potassium nutrients to spur healthy turf growth and disease resistance.
From my own use, I found that Sunniland Weed and Feed is unbeatable as a weed killer, as it effectively gets rid of a wide range of weeds like crabgrass and spurge.
Note that it Sunniland Weed and Feed for St. Augustine grass has no phosphorus, which means it may not be very suitable for a newly established lawn as a root-boosting fertilizer. I’d advise you to choose a high phosphorus content fertilizer for your turf after sodding such as Milorganite (6:4:0 NPK) or its alternatives.
5. Pennington Ultragreen Southern Weed and Feed
- 34:0:4 NPK fertilizer
- Kills henbit and clover in lawns
- Has 5% iron that makes grass greener
Pennington Ultragreen Southern Weed and Feed’s biggest selling point is that it’s both a quick-release and slow-release fertilizer. The fast-acting nitrogen will turn your St. Augustine turf into a lush green and dense lawn within a short period while the slow-release nitrogen ensures the turf stays fed for up to three months.
List of weeds it controls: henbit, clover, and chickweed.
Pennington Ultragreen Southern Weed and Feed is best applied during summer when St. Augustine is actively growing. You may, however, need to reapply it after a month if the weed problem on your St. Augustine lawn is severe.
6. Southern AG, 2, 4-D Amine Weed Killer
2, 4-D Amine Weed Killer by Southern Agricultural Insecticides is an effective herbicide against most broad leaf lawn weeds including poison ivy, clover, and dandelions. It contains other active ingredients that stimulate the growth of St. Augustine grass.
2, 4-D Amine Weed Killer is one of the most economical weed and feed products out there, with 1-4 pints being enough to cover up to an acre of St. Augustine turf.
What I found from my tests is that this Southern AG formulation is rather at eradicating oxalis weeds as they regenerate quickly via underground rhizomes.
7. Sta-Green Weed and Feed
- Kills up to 250 weeds
- Safe for St. Augustine grass
- 26:0:12 NPK fertilizer
Of all the weed control + fertilizer product on the market right now, Sta-Green Weed and Feed is arguably the most potent, as it can kill up to 250 different types of weeds. This product also works well on a wide variety of turfs, including St. Augustine lawns. When applied during the fall, it will protect your St. Augustine tough against extreme winter weather.
Sta-Green weed and Feed has an NPK ratio of 26:0:12, with the high potassium content ensuring your turf can effectively withstand diseases and dry weather. The only drawback against this product is that it’s ineffective when applied during the spring or the summer, which is St. Augustine’s active growing season.
Note: Weed and feed granules are tiny, herbicide-coated fertilizer pellets that stick onto weeds when applied on a wet lawn. Liquid weed and feed is usually diluted before being sprayed over dry or damp grass. These formulations promote a healthy, weed-free turf resulting in a thick St. Augustine grass lawn.
St. Augustine weed and feed schedule
The best time of the year to apply weed and feed product blends on St. Augustine lawns is during the growing season (spring-summer) when the grass is actively growing and the weeds are still young. You can also apply weed and feed that contains pre-emergent herbicides early in the spring before the weeds sprout.
Meanwhile, to ensure proper fertilizer timing (usually three weeks after the turf greens up), use a weed and feed that contains slow-release nitrogen. This type of weed and feed will still be releasing nitrogen into the soil for up to three months after it was originally applied as a weed killer.
Note: Some weed and feed products, like Sta-Green Weed and Feed are not meant to be applied during the spring or the summer.