Spring Maintenance Tips for Your St. Augustine Lawn

Spring Maintenance Tips for Your St. Augustine Lawn

Spring Maintenance Tips for Your St. Augustine Lawn

Seasonal maintenance on lawns slightly differs each season as temperatures and soil conditions change. In the spring, warm season turfgrass begins to come out of winter dormancy in most areas while cool season grass will continue to green up as temperatures rise. Some examples of warm season grasses are zoysia, bermudagrass, St. Augustine, centipede or bahia, while a few cool season grasses can be tall fescue, bluegrass or ryegrass.

This particular article lists some of the most important spring maintenance tips for your St. Augustine grass. Be sure to also refer to our St. Augustine homeowner maintenance guides for generic St. Augustine, Palmetto® St. Augustine and CitraBlue® St. Augustine.

St. Augustine Grass Spring Mowing

The timing for which the first mow of the spring for your mature, established St. Augustine widely varies depending on the area you live in. St. Augustine can come out of dormancy differently depending on the environment and temperatures your area encounters. For example, if you live in South Florida, your St. Augustine may have never entered dormancy at all during the winter. Many homeowners who live in South Florida will mow their lawn every other week during the winter—oftentimes starting in September and resuming a regular, weekly mowing schedule again in mid-March.

Generally speaking, mid-March is about the time for you to begin your regimen for spring green-up and mowing.

Keep your St. Augustine between two to four inches in height. These heights slightly vary for different brand names of St. Augustine. For example, Palmetto should be maintained at a height of 1.5–2.5 inches whereas CitraBlue should be kept at a height of 2.5–3.5 inches during the spring.

Lastly, a good tip for spring is to make sure your lawn mower blades are sharpened so that the mower blades neatly slice through the grass in place of ripping them. If the grass blades aren’t cut neatly, the mower is ripping them and opens the grass up to possibility of disease. Performing regular maintenance on your mower is good practice for the end of the mowing season or before spring takes place.

St. Augustine Grass Spring Fertilizing

With most St. Augustine grass coming out of dormancy, the spring is one of the most important times to use fertilizer. The fertilizer needs to promote healthy roots and the return of green leaf blades.

Be careful when making your first fertilizer application of the year though—it is common for homeowners to see their grass green-up and immediately pull out the fertilizer and lawn mower. We advise that you typically wait until the last frost has hit. If you fertilize your lawn and another frost hits, your St. Augustine will go right back into dormancy and you’ll have a harder time getting it to green-up again. This does more harm than good.

The date of the last frost varies from location to location. In the Florida Panhandle, for example, St. Augustine may not go dormant and will reach its full green-up in early February (depending on how cold the winter was). Even then, you won’t want to apply fertilizer until after Easter once the last frost has passed. Refer to the Farmer’s Almanac to figure out the last frost date for your area in 2021.

LawnifiTM Maintain, which is the first bottle of product you should use in the Lawnifi Spring Fertilizer Box, contains the perfect balance of nutrients to do this. Apply Maintain in the early spring.

In the mid-spring, you will want to apply the second bottle in the Lawnifi Spring Fertilizer Box, Boost. Boost is designed to deepen the green appearance of your St. Augustine lawn while delivering immediate greening benefits long into the season with its time-release formula.

In the late spring, use the last remaining bottle of Maintain to prep your lawn for the transition to summer’s stressful heat. Our patented nano-fertilizers with Catalyst TechnologyTM give your lawn the jump-start it needs to emerge from dormancy, green up fast and thrive throughout the spring months. Read Why Use Lawnifi Fertilizer? for more information.

Next, it is important to mention that you may start to notice spots of brown or straw-like grass while the rest of your lawn comes out of dormancy. This is usually a sign of disease. You do not want to apply fertilizer to a lawn with disease as the nitrogen in the fertilizer will feed the disease and promote its growth. Apply a systemic fungicide first and then wait several weeks before following with a fertilizer application.

St. Augustine Grass Spring Watering

Dormant St. Augustine doesn’t need much water until the active growing season kicks in and your grass starts to green-up. Once it starts to come out of dormancy, St. Augustine requires about one inch of water per week including rainfall. The same can be said for the different brands of St. Augustine like Palmetto or CitraBlue. If you aren’t sure how to measure how much water your lawn is receiving, an irrigation audit may be beneficial to you.

If you’re a homeowner who lives far enough south and your St. Augustine doesn’t go dormant during the winter, you may continue to regularly water your lawn in the winter. However if you live in South Florida, for example, you may turn your irrigation off completely during the winter and during the months of June–August when it rains a lot. The atmosphere in South Florida isn’t usually evaporating much water and the grass isn’t using it much during the winter, so frequent irrigation isn’t needed.

The next few tips in this article discuss spring applications for fungicides, herbicides or insecticides. If any of these control products or fertilizers are granular, you will need to water the product in so that your lawn absorbs it. This means that you will already be watering your lawn with the appropriate amount of water during the week of application. The same can be said with any liquid products as they are either products that attach to the end of your garden hose or require tank mixing with water.

St. Augustine Grass Spring Weed Control

The most important thing you can do for any weed issues your lawn may be having come springtime is to apply a pre-emergent herbicide. A pre-emergent herbicide functions to prevent weeds from emerging from the surface of the soil, as its name suggests. So if you know you get a lot of weeds in the summer like goosegrass or crabgrass, applying a pre-emergent to keep them from even appearing may be a good idea for you. It will also save you time, money spent on more product and effort from pulling the weeds that appear in the future. It’s actually not recommended you use an herbicide in the summer or winter, so pre-emergents can be especially useful for this reason. Read more about this in The Best and Worst Times for Herbicide Applications.

Pre-emergents should be applied during the spring when ground temperatures reach about 55 degrees Fahrenheit. The exact dates for these applications differ depending on the area you live in, but generally speaking, pre-emergents should be applied between March 1st and March 15th in the spring. For more information, read our blog on spring pre-emergent applications and refer to our recommended pre-emergent herbicides below. You can also receive a five percent discount on select pre-emergents from now until the end of March. Click here to learn more.

  • Coverage: 50 lbs. covers about 12,500 sq. ft.
  • Active Ingredient(s): Prodiamine 0.37%.
  • Ease of Use: Requires granular drop or broadcast spreader for application.
  • Best Used On/For: Established warm and cool season turfgrass before weeds appear.

  • Coverage: 5 lbs. covers between 50,000–80,000 sq. ft.
  • Active Ingredient(s): Prodiamine 65%.
  • Ease of Use: Requires tank mixing and application with a sprayer.
  • Best Used On/For: Established turfgrass before weeds appear.

Dimension 2EW Half Gallon

  • Coverage: 0.5 gallon covers between 87,000–228,000 sq. ft.
  • Active Ingredient(s): Dithiopyr 24%.
  • Ease of Use: Requires tank mixing and application with a sprayer.
  • Best Used On/For: Established turfgrass before broadleaf weeds appear.

If you notice any broadleaf weeds, control them with post-emergent herbicides. St. Augustine grass is sensitive to certain herbicides (2,4-D and MSMA), so read product labels thoroughly before applying. Southern Ag Atrazine and Spectracide Weed Stop For Lawns For St. Augustine and Centipede Lawns.

St. Augustine Grass Spring Insect Control

If your lawn has suffered from insect damage around this time in the past, it is a good idea to apply a broad-spectrum insecticide at this time to prevent them from coming back again. If the insecticide is a granular product, be sure to water it in so that it soaks into your soil. If it is a liquid product, you will either need to attach it to the end of your garden hose or tank mix it. Some of the most common spring insects in St. Augustine are white grub worms and chinch bugs. If you notice yellow spots in your lawn, check for chinch bug activity. You can read more about these insects in our Insect Identification blog. Refer to some of our most popular and effective insect control products below.

Spectracide Triazicide

  • Coverage: One bottle covers 2,500 sq. ft.
  • Active Ingredient(s): Gamma Cyhalothrin 0.08%.
  • Ease of Use: Hooks up to the end of your garden hose for even spray application.
  • Best Used On/For: Outdoor general insect control.

  • Coverage: 30 lbs. cover between 16,000–21,000 sq. ft.
  • Active Ingredient: Imidacloprid 0.5%.
  • Ease of Use: Requires a drop or broadcast spreader for application.
  • Best Used On/For: General outdoor insect control.

Bifen XTS

  • Coverage: One quart covers between 106,000–458,000 sq. ft.
  • Active Ingredient: Bifenthrin 25.1%.
  • Ease of Use: Requires tank mixing and spray application.
  • Best Used On/For: Pre- and post-construction termite treatments, turf and ornamentals and outdoor perimeter pest control.

Pictured above from left to right: White grub worms, Southern chinch bugs and a hunting billbug.

St. Augustine Grass Spring Fungus Control

As previously mentioned, circular brown or yellow spots may start to show up as St. Augustine comes out of dormancy. This is a sign of disease and you may need to make applications of a systemic fungicide. St. Augustine is also prone to gray leaf spot. Even if you don’t have disease in your lawn, it’s still good practice to apply it preventively to keep disease from taking over—especially if you’ve had disease in the past around this time. Systemic fungicide applications should take place before you apply any spring fertilizer. If you have fungus in your lawn, the nitrogen found in fertilizers oftentimes feeds it and helps it spread. Apply a systemic fungicide and wait a few weeks before applying any fertilizer.

Spectracide Fungus Insect Control Hose End

  • Coverage: One bottle covers 2,500 sq. ft.
  • Active Ingredient(s): Propiconazole 1.45% and Lamda-cyhalothrin 0.08%.
  • Ease of Use: Hooks up to your garden hose for even spray application.
  • Best Used On/For: Outdoor topical/contact fungus and general insect control.

  • Coverage: 10 lbs. covers between 2,500–5,000 sq. ft.
  • Active Ingredient(s): Azoxystrobin 0.31%.
  • Ease of Use: Requires a drop or broadcast spreader for application.
  • Best Used On/For: Systemic strobilurin fungicide used to control certain turfgrass diseases.

  • Coverage: 2 lbs. covers between 21,000–53,000 sq. ft.
  • Active Ingredient(s): Trifloxystrobin 8.33%, Tradimefon 41.67%.
  • Ease of Use: Requires tank mixing and spray application.
  • Best Used On/For: Preventative disease control.

Pictured above from left to right: Spring dead spot and gray leaf spot.

Lastly, if you notice thatch that is thicker than 1⁄2 inch, dethatch in late May. For compact soils, consider aerating in late spring instead.

Spring maintenance tips differ from other practices that take place during the rest of the year. Weather starts to warm up and everything will turn green again. Be sure to check out our individual Homeowner Maintenance Guides for  generic St. Augustine, Palmetto® St. Augustine and CitraBlue® St. Augustine.

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