How (And When) to Fertilize Your Lawn in Indiana

Like us, turfgrass needs proper nutrition to grow and thrive. But grasses come in different shapes and sizes, and have different needs. So one of the keys to getting the most out of your lawn here in Indiana is to understand how and when to fertilize it. 

Fertilizing is not a one-size-fits-all proposition. Just as there are different kinds of grasses, there are different kinds of fertilizer that affect grasses in unique ways. This guide will walk you through the best way to feed your lawn so you get the most out of it now, and year-round.

In this article: 

The Purpose of Fertilizer

In the wild, grasses draw nutrition from decomposing organic material. It’s not as simple when the grass is in someone’s yard, though. Grass planted in rich soil thrives with just some grass clippings as food. But when soil lacks nutrition, fertilizers are sent to the rescue.

Fertilizers mainly supply lawns with three nutrients: nitrogen, phosphorus, and potassium. These nutrients are abbreviated as N-P-K. Here’s what each of them does:

NutrientKey Benefits
Nitrogen• Helps rapid growth and protein synthesis
• Increases leaf development for dense lawns
Phosphorus• Helps early root growth
• Promotes plant maturity and seed development
Potassium• Increases drought and disease resistance

Before you embark on your fertilizing journey, make sure that you:

  • Calculate how much you need.
  • Don’t fertilize more than needed.
  • Use the right fertilizer.
  • Follow the instructions carefully.
  • Keep animals off your lawn for as long as advised or until the product has dried or settled (depending on the type).
  • Provide your lawn with at least a quarter of an inch of water after you fertilize, but don’t water too heavily because you don’t want to wash away the fertilizer.

Do You Need to Fertilize?

Man Holding the Fertilizer

Photo Credit: PxFuel

How much fertilizer you use (or if you fertilize at all) depends on a number of factors:

  • Location: Because southern Indiana’s growing season is longer than in the state’s northern reaches, the grasses in this area need more fertilizer.
  • Preferences: A thinner, lighter-colored grass needs less fertilizer than a dense, deep-green lawn.
  • Grass type: Different Indiana grasses have varying fertilizer needs.
Needs More FertilizerNeeds Less Fertilizer
Kentucky bluegrassZoysiagrass
Perennial ryegrassTurf-type tall fescue
  Fine fescue
  • Age and state of lawn: New and neglected lawns need more fertilizer.
  • If you leave clippings on your lawn: Leaving grass clippings on your lawn provides it with many necessary nutrients.
  • Weather: If it’s been raining more than usual in the summer, it may necessitate more fertilizer.
  • Soil type: Very sandy and very clay-heavy soils need more fertilizer than silt loam soils.
  • Soil test: It’s important to conduct a soil test before using fertilizer to know exactly which nutrients your grass is lacking.

What’s a soil test?  A soil test analyzes the nutrient content, pH level, and other properties of the soil to determine how well your grass can grow. It identifies the nutrients your soil lacks and recommends the right fertilizer.

You can do either a DIY soil test or send a soil sample to a laboratory for a detailed report. Purdue University recommends testing your soil every 3 to 5 years, but more frequent soil tests can be beneficial too.

Indiana Fertilizer Calendar

If you need to fertilize, Purdue University recommends fertilizing in these months for optimal performance:

AprilIf you apply a pre-emergent herbicide, use a product with little to no nitrogen; if it does contain any nitrogen, it should be slow-release, ideally organic
MayIf you didn’t fertilize in April, fertilize now with a product containing mostly slow-release nitrogen
JuneConsider fertilizing with nitrogen if there’s been a severe disease outbreak
JulyFertilize with a product containing slow-release nitrogen if there have been above-average rainfalls or if you’ve been irrigating
August Consider fertilizing with nitrogen if there’s been a severe disease outbreak
SeptemberFertilize with nitrogen
OctoberConsider fertilizing with nitrogen if there’s been a severe disease outbreak
NovemberPurdue University recommends using quick-release fertilizer in November, but be aware that it may be harmful to the environment and wildlife; slow-release fertilizer is better

You may not need to fertilize this much; these tips are for the most high-maintenance lawns.

For precise dosages and more information, you can check out this lawn care calendar from Purdue University.

Is Organic Fertilizer Better?

When we talk about fertilizer, we’re often referring to chemical products. However, organic fertilizers are also effective and have the added benefit of being environmentally friendly. They release nutrients slowly over time, promoting healthy soil and plant growth. 

There are many options for fertilizing your lawn organically, but they can be summed up into these two categories:

  • Grass clippings: If your soil test shows that you have healthy, nutrient-rich soil, you can get away with just leaving grass clippings on your lawn after each mow. Make sure you don’t leave too much and that they aren’t stuck together.
  • Organic fertilizer: If your soil is lacking nutrients, you can use store-bought organic fertilizer or even make it yourself.

Because organic fertilizers are natural, many people think that they’re harmless. The truth is, organic fertilizers still contain ingredients that may harm people and animals. Plus, animals are often attracted to some organic fertilizers because of their smell. Moreover, many store-bought fertilizers are mixed with hazardous ingredients to make them more efficient.

So what’s the bottom line? Regardless of which fertilizer you use, be cautious and follow the instructions carefully. 

Fertilizer Types

Man holding soil in hand and bucket of fertilizer

Photo Credit: CanvaPro

Apart from organic and inorganic fertilizers, fertilizers are further categorized so that homeowners can get a product that’s right for their needs.

You can choose from dry or liquid fertilizers:

  • Dry fertilizers: Usually slow-release fertilizer that comes in granular form.
  • Liquid fertilizers: Has to be diluted with water; usually quick release.

It’s also important to note the difference between slow- and quick-release fertilizers:

  • Slow-release fertilizers release nutrients over a longer period of time. They’re usually better for grass and the environment. Organic fertilizers are slow-release, too.
  • Quick-release fertilizers affect soil right away. They’re sometimes used as a quick nutritional boost. But they’re more likely to cause damage to your lawn and the environment. 

In summary, most lawns can benefit from using slow-release fertilizer.

When Not to Fertilize

There are some conditions that aren’t ideal for fertilizing. Those include:

  • In the wrong month: The best time to fertilize in Indiana is between April and November.
  • During a drought: That’s right; even though applying fertilizer in dry conditions might seem like a good idea, it actually damages your grass.
  • After rainfall: Fertilizing wet grass is also a bad idea. It can create runoff, and your fertilizer might not even get absorbed.
  • If you expect traffic on your lawn: You need to be sure that your lawn can be left alone after you apply fertilizer.

When to Hire a Lawn Care Pro

Feeding your lawn the right nutrients is vital to its overall health and appearance. But it’s necessary that you also perform other maintenance jobs throughout the year, such as mowing, watering, overseeding, and so forth.

Sounds like a lot of work? Wikilawn connects you to the best best Indiana lawn care pros so let them take yard care off your to-do list.

Main Photo Credit: Canva Pro

About Wikilawn

Wikilawn’s mission is to provide the best resources and information to help you enjoy your outdoor spaces the way you want. Whether you are a DIY, lawn-loving, gardening guru, or someone who wants help in picking a local lawn care professional, we can smooth your path to a beautiful backyard!

About Wikilawn

Wikilawn’s mission is to provide the best resources and information to help you enjoy your outdoor spaces the way you want. Whether you are a DIY, lawn-loving, gardening guru, or someone who wants help in picking a local lawn care professional, we can smooth your path to a beautiful backyard!