St. Augustine is a turfgrass that makes for a thick green lawn, especially in warm coastal areas like Florida, the Carolinas, and Southern California. However, it does require a decent amount of maintenance, and one of the most important things when maintaining a St Augustine lawn is fertilization. Weed and feed fertilizers not only provide fertilization, but also weed killer. Basically 2 for the price (and effort) of one.
Here are the 8 best weed and feeds specifically used for St Augustine lawns.
See Also: The 8 Best Fertilizers for St Augustine
1) Pennington Ultragreen Southern Weed And Feed
Specialized products are typically better than general products for lawn care. This is especially true when working with St. Augustine grass, which requires somewhat different care and isn’t compatible with some other popular options.
Pennington’s southern mix includes 22.1% nitrogen in slow-release form, which is relatively high for a weed and feed product, and it helps control weeds for up to three months. As a Summer weed and feed, it’s ideal for controlling weeds after they emerge on established lawns, making it excellent for maintaining your current grass coverage.
Why We Like It
- Provides excellent Summer control
- You can wait to apply it until you know you need it
- Contains iron for fortifying lawns
Our Verdict
Overall, this is an excellent product and worth your first look for a weed and feed. The iron enrichment is a nice touch for lawns, while the Summer application means you may want to get and use it even if you buy another fertilizer for Spring. Most stores sell this at a highly competitive price point, too, which makes it much easier to fit into the average gardening budget.
Editor’s Rating: 5/5
2) Sunniland St. Augustine Weed And Feed
In many ways, this is the opposite of our top choice. Sunniland’s mix is suitable for use in every season except Summer, and it contains a 50% slow release mix that controls plants for up to 90 days at a time. It also contains no phosphates, which is better for local waterways and one of the reasons we decided to place it so high on this list.
This product focuses on St. Augustine almost to the exclusion of other grass varieties. If you’re seeding, you’ll need to wait eight weeks, which is moderately high but not the worst we’ve seen for planting.
Why We Like It
- Specially designed for St. Augustine grass
- Usable throughout most of the year
- No phosphates
Our Verdict
This is an excellent product overall and an outstanding companion to our #1 choice. If you want to fertilize throughout the year, these two products together provide all the coverage and control most lawns need.
The one notable flaw of this product is that companies usually sell it exclusively in 5,000 square foot bags, which means you’ll need to buy several bags if you need to cover more area.
Editor’s Rating: 5/5
3) Sta-Green Weed and Feed
Sta-Green’s Weed and Feed blend is one of the most impressively versatile products on the market, capable of working on practically any variety of lawn grass while providing excellent pest control. In addition to helping kill more than 250 types of weeds, which is the highest you’re likely to see on a weed and feed product, it also helps protect against harsher Winter weather.
However, that strength is also a drawback. This is a winterizer product that helps prepare St. Augustine grass for Spring growth, but it’s not effective if you use it anytime outside of Fall. That automatically makes it a more inferior choice for controlling weeds during St. Augustine’s growing season, but it’s still a useful product for strengthening your lawn.
Why We Like It
- Competitive pricing
- Supports deep root systems
- Does things Spring and Summer fertilizers don’t
Our Verdict
This weed and feed product is best when you need to strengthen and establish your lawn. It’s not quite as effective on fully-established lawns, though you may want to use it anyway if you have tough winters and want to protect your lawn as much as possible.
Editor’s Rating: 4.5/5
4) Scotts Snap Pac Weed and Feed
Scotts is one of the most popular manufacturers, and their experience shows with options like their weed and feed Snap Pac. This is a relatively new product designed for Scotts’ proprietary Snap spreader system. You’ll need to buy that separately if you want to use this fertilizer, but since the Snap Pacs automatically set the spreader to the right setting, it takes a lot of guesswork and adjusting out of the process.
Each bag covers up to 4000 square feet of lawn, which is a little on the low side and part of why this product is lower on our list.
Why We Like It
- Easy to use with the right spreader
- Useful in both Spring and Fall
- Ideal for those not familiar with fertilizing
Our Verdict
The Snap Pac is a little more expensive than some of the other weed and feed options on our list, but its impressive weed control and ease of use put it in a class of its own. If you have a small lawn and want to limit how often you fertilize it, this is an excellent product to start with.
Our Verdict: 4/5
5) BioAdvanced 3 in 1 Weed and Feed for Southern Lawns
BioAdvanced doesn’t have very many products on the market, but their three-in-one mix is outstanding for nourishing St. Augustine lawns while also controlling crabgrass and other common weeds. The fertilizer duration is a little short at just two months, but the weed protection lasts for up to six months, which is ideal if your lawn is mostly established already.
Make sure you only get the Southern Lawns bag. BioAdvanced has a few similar-looking products that aren’t suitable for St. Augustine grass and could harm your lawn if you use them.
Why We Like It
- Highly effective formula
- Longer-term weed protection than competitors
- High nitrogen content
Our Verdict
This is one of the best weed and feed options for St. Augustine lawns. Its price is roughly in the middle for weed and feed products, while its highly-effective formula is excellent at controlling weeds. We recommend this product if your soil is mostly good, but you need to control weeds for a long time so that your lawn can establish itself better.
It’s most effective in Spring and Summer, so consider getting a winterizer product like our #3 choice from Sta-Green.
Editor’s Rating: 4.5/5
6) Scotts Turf Builder Southern Triple Action
Scotts was going to get onto this list at least twice no matter what we did, but their Southern Triple Action bag is worth a look for any buyer. In addition to killing many types of weeds and feeding St. Augustine lawns, this blend also prevents common pests like fire ants, grasshoppers, ticks, and fleas from living in the area.
The insect protection is long-term, too, with the protection lasting for six months when this product is applied correctly. Not all fertilizers stop insects, so if they’re a problem in your area, consider trying this product first.
What We Like
- Long-term effectiveness
- Allows multiple treatments when necessary
- Minimal waiting time if planting seeds
Our Verdict
The insect-killing property is the real selling point of this weed and feed. This is a surprisingly rare quality, and it’s a significant factor in our decision to include this product on our final list. Scotts sells this in 4000 and 8000 square foot bags, which is different from the industry standard but still viable for most homeowners.
The Southern Triple Action formula is more expensive than most alternatives, but if you’re buying it to fertilize your lawn while stopping insects, we think it’s worth the price.
Editor’s Rating: 4.5/5
7) Spectracide Weed & Feed
Spectracide’s Weed & Feed is a budget-friendly liquid option that only requires a hose and the ability to walk at a steady pace. Each bottle treats up to 7,500 square feet of grass, though in practice this varies based on how fast you walk. This blend focuses on controlling broadleaf weeds and may not be quite as effective on other types of harmful plants and pests.
Why We Like It
- Easy to use
- Covers a large area for its price
- Ideal for supporting established lawns
Our Verdict
Solid weed and feed options are the best choice for long-term support, which is what growing lawns need. Liquid fertilizers like this one serve as upkeep for existing lawns that don’t need as much external support. For that reason, we can’t recommend it to everyone despite its low price and ease of use.
However, if your lawn only needs a little care to stay healthy, liquid fertilizers like this one are among the best options currently on the market.
Editor’s Rating: 4.5/5
8) Sta-Green Ready-to-Spray Weed and Feed
Another liquid fertilizer, Sta-Green’s formula is suitable for almost all grass types and contains 20% nitrogen for excellent weed control. Like most liquid products, it covers about 7,500 square feet and is extremely easy to use as long as you have a hose long enough to reach your whole garden.
Sta-Green recommends using this anytime weeds are actively growing. However, they also suggest watering heavily 1 to 2 days before applying this product, which requires more planning than some other weed and feed products.
Why We Like It
- Extremely easy to use
- Better for southern grasses like St. Augustine
- Effective on most broadleaf weeds
Our Verdict
This is a solid alternative liquid fertilizer, though it’s a little more expensive than our previous recommendation. However, at just 20 minutes per bottle, this is a fast and easy way to fertilize lawns as needed. We view this as a supporting product rather than a primary weed and feed mix, better for established lawns than those that are still growing in.
However, note that this product does not have any Potassium or Iron included. If you need to adjust your soil a bit more, consider using another weed and feed instead of this mix.
Editor’s Rating: 4.5/5
Frequently Asked Questions
Which Products Are Best For Promoting Thick Sod?
That depends on various factors, including the quality of your soil and how dense your lawn already is. However, weed and feed products with iron and potassium are usually better at increasing sod density. Also, weed control is more important while your lawn is developing sod. Once that’s established, it will help prevent weeds from growing at all.
.How Aggressive Should I Be About Weeding And Feeding St. Augustine?
Short answer: read the instructions.
Generally you’ll want to apply weed and feed in early spring, especially if it includes a pre-emergent herbicide. Pre-emergents prevent weeds from sprouting, so while it takes care of a ton of weeds, it won’t help with winter weeds that were already there. If it contains a post-emergent herbicide, you’ll generally want to fertilize in late spring or throughout the year, depending on your climate.
How Aggressive Should I Be About Weeding And Feeding St. Augustine?
You should be very aggressive while your St. Augustine is building its sod layer. Killing weeds down to the roots makes it easier for St. Augustine to build the densest possible protection for itself. Once it’s fully established, it still needs care, but not as much.
Fertilizer is one of those things where more does not mean better. If you overapply, you may see a yellowing of the lawn, which is typically due to nitrogen burn.
What is St Augustine grass?
St. Augustine is a warm-season grass often used for lawns, pastures, and other large areas. While it strongly prefers warm areas, growing all along the southern parts of the United States, it can also tolerate colder coastal regions that have mild winters.
St. Augustine grass is particularly valuable for its thick sod, which helps eliminate other grasses and weeds to create a uniform appearance. However, getting the sod to this point requires care and maintenance during its primary growth phases, after which owners can switch to maintaining it. Thought St Augustine is most common in states like Florida, it grows well in many southern climates assuming the soil type is right.
This grass grows best in soil with a pH between 5 and 8.5, which is a broader range than many of its competitors. If you want to plant St. Augustine, be sure to check the soil in your area to help determine whether or not this grass is a good fit. You may need to adjust your soil before adding grass.
St Augustine grass lawns are extremely thick. They require frequent mowing (never cut more than 1/3rd the blade length) with sharpened mower blades.
Where is St Augustine grass grown?
If you have a St. Augustine grass lawn, there is a good chance you life in Florida – that’s the ideal climate for St Augustine. However, the grass also grows well in the costal Carolinas, the gulf coast, and southern California. Basically anywhere that’s warm year-round and is close to water.
Want to learn more about St Augustine Care?
Having a healthy lawn with perfect green color doesn’t come easy, and the techniques used depend on grass types. For more info on St Augustine care, we recommend the video below by Franklin Hernandez.
Top Pick
The Pennington Ultragreen Southern Weed And Feed mix is a particularly good choice for St. Augustine lawns. You can wait to use it until you know you need it each year, and the added iron is ideal for enriching your lawn and building up sod.
Premium Choice
The Scotts Turf Builder Southern Triple Action formula is relatively expensive, but its anti-insect properties are a rarity in weed and feed products and are worth the price if you’re trying to protect your home from invaders. Consider hiring an expert to check which insects threaten your house before you buy any weed and feed.
Great Value
The Sta-Green Ready-to-Spray Weed and Feed is affordable even on a tight gardening budget. While it’s not quite as effective as other solid fertilizer, it’s an excellent choice for maintaining St. Augustine lawns that already have their protective sod layer fully in place.
Looking for weed and feed for another grass type? Check out our other buying guides:
- Best Weed and Feed for Rye Grass
- Best Weed and Feed for Bermudagrass
- Best Weed and Feed for Fescue
- Best Weed and Feed for Zoysia
Table of Contents
