9 Spring Lawn Care Tips for St. Louis

Someone holding their hand next to grass to show height

The last frost in St. Louis means it’s time to put away the ice skates and break out your lawn mower. Your yard might not have all the vibrant colors found at the Missouri Botanical Gardens, but you can get your yard in great shape by following some simple spring lawn care tips.

These are our top tips for spring lawn care in St. Louis:

  1. Prepare to mow
  2. Protect your soil pH
  3. Knock out weeds
  4. Assess your drainage
  5. Don’t let fungus fester
  6. Mow
  7. Water
  8. Dethatch
  9. Mulch

1. Prepare to mow

Looking down onto a manual push mower mowing the lawn
Andrew Gustar | Flickr | CC BY-ND 2.0

Just like you need a morning stretch, your turf tools need a good dust-off when spring comes around. The last thing you want is a dull mower shredding your growing grass! 

Why are sharp blades important?

A dull blade can injure your lawn, just like a dull razor can hurt your skin. A sharp blade isn’t just important for aesthetics, though – it helps prevent disease. The wounds left by a dull mower are prime entry points for fungal diseases to take hold. Not to mention, the strain from a dull blade can shorten the lifespan of your mower.

How often should you sharpen your blade?

The professionals say you should sharpen your mower blade every 20-25 hours of use. So if you mow your yard for an hour once a week, that means you’ll need to sharpen your mower blade every 20 weeks or so. It’s a good idea to change the oil in your mower around this time, too.

Removing and cleaning your lawn mower blade:

  • Disconnect the spark plug.
  • Empty the gas tank.
  • Turn it on its side so the carburetor’s facing up, then mark the bottom of the blade with a marker so it’s easy to install it right-side up after you are done.
  • Use a wrench or ratchet to loosen and remove the nut that holds the mower blade in place.
  • Clean it with a dry rag. If you need extra grit removal power, spray it with penetrating oil, let it sit, and scrub it with a brush.

Sharpening your mower blade by hand:

  • Make sure to wear protective gloves and eyewear.
  • Place the blade in a vise.
  • Use a file or grindstone to sharpen the blade from the top side of the cutting edge. Push in one direction, following the blade’s angle.
  • When it’s as sharp as a butter knife, release it from the vise, turn it over, and repeat on the other edge. You should be able to sharpen it with fewer than 50 strokes.

After you’re done, be sure to clean out any debris from the bottom of the mower before attaching the blade back to the bolt. To finish, reconnect the spark plug and refill the gas.

2. Protect your soil pH

Testing for pH isn’t just for middle school science classes. It’s important to test your soil pH, especially if you’ve been applying fertilizers in the past. 

Many St. Louis yards have a high or very high soil pH and are receiving unnecessary fertilization, causing chemical runoff to lakes and rivers. It can take years to bring soil test levels back down to normal, so don’t skip this important step. 

You can use a soil probe or a spade to collect samples for a soil test. For turf areas, dig your tool in 3 inches and take samples from several areas. Put each collection in its own container, then break up all the lumps and remove debris. Let them dry overnight at room temperature. Finally, mix all your samples together into one bucket and submit your sample to a soil testing lab.

Adjusting pH is simple. For soils that score on the acidic end (below 6.0), apply limestone. For soils that lean basic (above 7.2), apply sulfur. Most turfgrasses do best in soil between 6.3 and 7.2. 

Limestone recommendations (lbs./1,000 square feet)

pHLoam soilClay soil

Sulfur recommendations (lbs./1,000 square feet)

pHLoam soilClay soil

If your lawn’s pH needs more than 5 lbs. of sulfur per 1,000 square feet, spread out applications over time. 

Need help figuring out if your soil has more loam or more clay? The easiest way is to take a handful of damp soil, preferably a day or two after watering, and squeeze it. If it falls apart when you prod it, you have loamier soil. If it stays clumped together even when prodded, your soil has more clay. 

3. Knock out weeds

dandelion weeds in a grassy patch
Paul Swansen | Flickr | CC BY-ND 2.0

Warm weather means everything’s growing – including weeds. Pre-emergent herbicides kill weeds before they germinate. In Missouri, they should be applied between mid-March and mid-April. If you missed the cutoff and your yard is starting to look a little wild, you can use a nonselective, post-emergent herbicide like glyphosate. For crabgrass, spray when plants have at least three leaves.

Looking for an organic approach to weed control? Try setting your lawn mower height to 3-3.5 inches; the shade from taller grass prevents weeds from germinating. Corn gluten meal herbicide is another organic option, but it’s only about 65% effective compared to the synthetic alternative. It also should not be applied within six weeks of turfgrass reseeding. Pulling weeds is always an option if the weeds are confined to a small area. 

Remember, the number one weed killer is simply a healthy turfgrass. Following good practices of watering, fertilization, and mowing is your best defense, as well as knowing what kind of grass works best with your particular yard.

4. Assess your drainage

Water is very important to your landscape, and so is where it goes. Though rain is a great way to save on water costs, you don’t want standing stormwater in your yard. It can hurt your turfgrass, breed disease, and lead to erosion.

Checking if you have a drainage issue is simple. Wait for heavy rain, then inspect your yard for any pooling water. You might notice standing water beneath your downspouts, soggy areas of your lawn, or fissures forming in the soil. If you do, follow the steps below.

Clean and repair downspouts and gutters: The only thing that belongs in your gutters is water. If you don’t have a gutter screen or guard, leaves and debris will collect and prevent proper drainage. 

  • Get your garden trowel, spade, or spatula ready for scooping.
  • Position your ladder on flat, dry ground. 
  • Scoop out debris into a bucket or onto a plastic tarp below, working in small sections.
  • Inspect for leaks as you go along. These can be fixed later with waterproof sealant spray or tape. 

For downspouts, just place a hose into the top opening. You also can use a plumbing snake to clear leaves. 

Clean drains: If you have other drainage systems like French drains and channel drains, it’s important to keep those clean, too. 

  • Remove the drain cover. Some can be opened with a screwdriver for leverage and others will have screws you need to remove.
  • Clean out debris by hand or with a shop vac. 
  • Flush the pipes with a garden hose until the water runs clear at the termination point.
  • Reattach the grates.

If there’s still standing water, you can puncture the ground with a pipe or drill bit to break the soil barrier. If you are looking to add a more natural feature to your yard, you can always add a rain garden. A rain garden is a collection of grasses and flowers planted in a depressed area that uses runoff water. It’s a cost-effective way to reduce runoff from your property. Try planting wildflowers and native plants to make a beautiful, natural rain garden. 

5. Don’t let fungus fester

patches of grass that are brown or missing in a yard
Brian Hart | Flickr | CC BY-SA 2.0

A healthy turf in spring sets the stage for the rest of the year. This is a great opportunity to address any diseases that might have attacked your lawn in the winter months. Scan your lawn for any brown patches, areas of dead grass, or whitish substance on the grass blades. 

Pro Tip: It’s best to check your lawn at dawn. The morning dew will make it easier to notice fungal webbing.

These are a few of the most common St. Louis turf diseases and how to identify and treat them. A common theme in treatment is the proper application of fertilizer and dethatching to improve air circulation. 

Brown patch

What to look for:

  • Round patches turning brown. You can distinguish this from other diseases because the patches will appear wet. Sometimes a gray smoke ring will appear around it. 

How to treat brown patch:

  • Use slow-release nitrogen fertilizer in early spring and remove lawn clippings from diseased areas. You also can use a fungicide and replant dead areas.

Dollar spot

What to look for:

  • Round, straw-colored patches around 4-6 inches in diameter. There will be a reddish area around the edge, and the patches will be slightly sunken.

How to treat dollar spot:

  • Excessive nitrogen fertilizer increases susceptibility, as does excess thatch. As with other fungal diseases, ensuring good air circulation in your turf is important.

Fairy ring

What to look for:

  • A light green patch with a dark green ring around it anywhere from 2-100 feet in diameter. Mushrooms also can appear on the border. 

How to treat fairy ring:

  • Fairy ring is sometimes caused by organic debris in your soil. If it keeps coming back, you might have to discard or kill the sod around the zone, then mix the ring and non ring dirt. Use a soil needle to aerate in the diseased area. Dethatching and fungicide application also can help.

Necrotic ring spot

What to look for:

  • Necrotic ring spot shows up in one to three places in your turf. You’ll see purple or reddish leaves in patches that usually expand more than a foot in diameter.

How to treat necrotic ring spot: Don’t apply fertilizer in the spring because it can worsen the disease. Dethatching, mowing high and often, and watering deeply but infrequently helps. A fungicide can be used, as well.

Don’t mow low – grass should be kept 2-3 inches high and mowed frequently so you’re never removing more than one-third of the leaf. If you decide to use a fungicide like azoxystrobin, chlorothalonil, iprodione, or ziram, make sure to water deeply a few days before. In the fall, apply 1-3 lbs. of nitrogen per 1,000 square feet.

6. Mow

As we know, a good haircut can make or break your look. Same for grass! Proper mowing helps prevent disease and weeds, and protects your turf’s health. 

The first step is knowing what kind of grass you’re working with. Here’s our list of the most common turf types in St. Louis, what they look like, and how to mow them.

GrassTypeMowing height (inches)
Tall fescueCool-season2.5-3.5
Kentucky bluegrassCool-season2-3
Perennial ryegrassCool-season1.5-2.5

7. Water is key

Sprinkler on in a yard
Delwin Steven Campbell | Flickr | CC BY 2.0

If it’s time to mow, it’s time to water. You should start your watering routine when your grass is actively growing. You should wait for your lawn to tell you when it needs to be watered by the grass wilting, curling, or folding.

Getting your sprinkler system ready:

Just like your other equipment, your sprinkler system needs a check-up before it’s ready for action. Following these steps can prevent costly damage.

  • Make sure there’s no frozen ground. Dig a shovel a foot into your ground to make sure. If you turn the system on too soon, you could break the water lines. 
  • Review your control panel’s settings. Replace the batteries if it has a battery backup. 
  • Inspect your sprinkler heads and clean the nozzles. An old toothbrush works well for this.
  • Make sure all the valves are closed except for the one farthest away from the main water source (this allows air to escape when you turn on the water).
  • Open the main valve slowly until you can hear water. Turn it a few more degrees every couple of minutes to prevent a surge of pressure from breaking valves.
  • Wait until the water flowing out is clear, then close the valve you left open.

It turns out that too much of a good thing can be a bad thing. You might think it’s best to make sure your lawn’s wet every day, but grass prefers deep, infrequent waterings. In general, yards need 1 inch of water per week. If your soil is on the sandier side, you’ll need more frequent watering. If you have rich soil, once a week is fine. 

A solid way to check your lawn for moisture is to stick a screwdriver into the dirt. If it’s easy to drive in, your soil is moist. If it’s hard to get into the dirt, your soil might be too dry. 

8. Dethatch

Early spring is a great time to dethatch your lawn, especially for cool-season grasses. Thatch occurs when grass grows too quickly for the dead leaves to decompose, creating a layer of dead grass woven in the living plant. A little bit of thatch is fine and can even help your lawn thrive. 

What happens when you have too much thatch?

  • It traps moisture in your lawn, creating a breeding ground for fungal disease.
  • It can be a barrier between nutrients and the soil.
  • It can host pests.

You’ll know you have a thatch problem if your lawn is brown or spotty, has pest problems, or feels spongy. 

How do you dethatch?

You have two options: use a rake or a dethatcher. A dethatcher, similar to a rake, uses metal blades or tines to comb through the grass but requires less effort on your part. 

  • Wait until your grass can be mowed.
  • Mow it at half its normal height.
  • Use a dethatcher or a rake to pull up the thatch.

After dethatching, you might notice bare spots in your lawn. You can overseed those areas with new grass seed to make them lush again. Dethatching will ensure the seeds come into contact with the soil and help the new grass grow.

9. Mulch

Large pile of mulch with a wheelbarrow next to it
Joe Hoover | Flickr | CC BY-SA 2.0

Mulch is the unsung hero of landscaping. It’s easy to apply, and sometimes you can get a free bag from a local tree service.

The benefits of spreading mulch include:

  • Keeps moisture in
  • Tamps down weeds
  • Provides organic matter for soil as it decomposes
  • Helps with erosion control
  • Protects tree roots from mowing
  • Creates borders in your lawn

We often think of the classic wood chip mulch, but there are lots of other options, some of which you may already have laying around the house. 

Organic mulchesInorganic mulches
Wood Rubber
Pine straw

Before you apply your mulch, remember to rake out any old material (this helps prevent pests too). Don’t overdo it: You only need a layer 2 inches deep. For trees, start your layer of mulch 3-6 inches away from the trunk and carry it out 3 feet. 

Wait until after the last frost to apply your mulch so you don’t trap cold air around your plants.

Help your St. Louis lawn get off to a good start this spring

After the long, cold St. Louis winter, you need to give your lawn a little TLC. Proper fertilization, watering, weed control, disease control, and mowing will help your lawn thrive the whole year.

If your spring cleaning list is already too long, contact a professional landscaper in St. Louis for help. They’ll take lawn maintenance off your hands so you can get back to enjoying the warm weather.

Main Photo Credit: Ivan Radic | Flickr | CC BY 2.0

Rachel Abrams

Born and raised in Gainesville, Florida, Rachel Abrams studied creative writing at the University of Virginia. She enjoys volunteering at her neighborhood community garden and growing herbs in her New York City apartment.