Best Time to Fertilize Lawn Before or After Rain

Best Time to Fertilize Lawn: Before or After Rain?

Is your lawn the one on the block with a thick, weedless stand of grass? Or are you envious of those perfect lawns while yours is a little on the lame side? If you fit the first example, you know that fertilizer is the key to creating and maintaining gorgeous turf. But, if you fit the second example, read on. You are about to learn everything you need to know: the best time to fertilize lawn (before or after rain, and the fertilizer I use) to get the lawn you’ve dreamed of.

Understanding Why You Need to Fertilize

Some of the most vital information you need to know is what fertilizer is made of.

This will help you understand why fertilizer is helpful, how it works, and will guide you toward buying the right type for your lawn.

Is the Best Time to Fertilize Lawn Before or After Rainfall?

The fertilizer you put on your lawn plays an essential role in making your yard look thick and green, but this is just the beginning.

The nutrients in fertilizer help prevent weeds from smothering and crowding out healthy grass.

Below is a list of three critical nutrients in your fertilizer and their functions in producing the yard you desire.

  • Nitrogen is the main reason grass gets thick and green. Nitrogen encourages leaf growth. Your lawn naturally gets some nitrogen from rainfall, and from mulched grass clippings, but adding a controlled amount of nitrogen by fertilizing ensures your grass has the nourishment it needs to become a thick and green lawn.
  • Phosphorous is essential for a strong root system. Phosphorous stimulates root growth and also helps grass seeds sprout for a thick and healthy lawn. The more grass you have in your yard, the less room there is for weeds. Healthy roots help lawns survive droughts as well.
  • Potassium is like an immunization for your lawn. It helps grass resist harmful elements and conditions that compromise its health, such as drought, disease, fungus, foot traffic damage, and extreme weather conditions. It is an especially essential nutrient for the overall health of your lawn.

Types of Lawn Fertilizer

With all the different kinds of fertilizer, it’s hard to know which one you need.

I group fertilizer generally into two categories – synthetic, and organic. Synthetic fertilizers are made in a lab, organic fertilizers are made naturally.

Damp Grass - Should You Fertilize Before or After Rain?

The difference between the two really is that synthetic fertilizers feed the plant, and organic fertilizers feed the soil.

While you might see better short-term results from synthetic fertilizers, I find that over time your lawn will depend upon them because your turf will be depleted.

So. A few factors help determine which type to purchase.

First, different types of fertilizers are made for specific application times.

Forget about all of the marketers telling you to fertilize constantly so you buy more … here on planet Earth you can fertilize your lawn just about any time of year as long as you buy the right fertilizer.

Mowing Thick Green Grass

Some people feed several times per year, but most people do not have that kind of time or money. 

If you are only going to fertilize one time during the year, follow these general rules:

  • Fertilize in September for cool-season northern grasses.
  • Fertilize in June for warm-season southern grass.

Personally, I fertilize 4 times annually with a slow-release organic fertilizer called Milorganite (Amazon link). You can read more about that product, and the application schedule I follow here.

Granular vs Liquid Fertilizer

Most people choose a granular fertilizer because it is cheaper to buy in bulk, and it is also easier to store and preserve.

Granular fertilizer dissolves over a period of time, offering a steady release of nutrients to your lawn.

Liquid fertilizer, however, does have its place.

It is easier to apply evenly and is more easily absorbed by your turf.

You might use liquid fertilizer instead of granular to address specific problems. Liquid fertilizer gives you more control over the dosage and is immediately absorbed for instant lawn repairs.

Does Rainfall Play a Role in When You Fertilize?

One question that seems to stump people is what role rainfall plays when determining when to fertilize.

Is the best time to fertilize lawn before or after rain falls?

Let’s begin by listing two times when not to fertilize to help clear the confusion.

Should I fertilize My Lawn Before or After Rain?
  1. Do not fertilize your lawn during a drought. Even if you plan to water, feeding your grass when it is stressed from heat and dryness is mostly ineffective, and a waste of time, product, and money.
  2. Do not feed your lawn right before a heavy rain. A heavy rainfall will cause the fertilizer to run off or pool in concentrated areas before it can break down and be absorbed. Run-off is a bigger problem than just failing to nourish your lawn. Fertilizer can wash out of a yard and pollute other areas, especially waterways.

So, if you don’t want to fertilize right before a heavy rain … when should you feed your lawn?

The following best practices should be of some guidance.

  1. Before a gentle rain– Watch the weather and try your best to fertilize a few days before a gentle rain. Understandably, predicting the weather is tricky, so the next suggestion for fertilizer application might be easier to achieve.
  2. After a rain – Fertilizing a few days after a rain is easier than predicting the rain and trying to apply before it. But convenience is not the only reason you should apply fertilizer after a shower.

Why is Fertilizing Your Lawn After a Rainfall Best?

Applying fertilizer after a rain is more eco-friendly because you don’t risk polluting water sources with run off.

Fertilize Lawn After Rain

Additionally, your lawn will receive nitrogen from the rainwater it absorbed a few days prior, which improves the overall health of your lawn.

Adding additional nutrients when your lawn is not stressed will enhance the effectiveness of the fertilizer. It will help your lawn grow and thrive, rather than helping it recover.

Tips for Applying Fertilizer After a Rainfall

  1. It is best to wait a day or so after a rain before applying fertilizer. At this time, any pools of water will be gone, but the ground will still have moisture in it.
  2. Do not apply fertilizer on grass blades that are still wet.
  3. Check the forecast and make sure some sunshine is in order. Sunshine is necessary in the process of photosynthesis, which enhances the fertilizer and creates healthy growth.

When I Fertilize My Lawn

My favorite time of day to fertilize is late afternoon, a day or so after rainfall.

This ensures that kids aren’t running on the lawn in the next 12 hours since it’s just before dark, the blades of grass will be dry from the sun, and the dew overnight will help the fertilizer adhere to the turf.

Let it Rain!

Fertilizing is an essential step in having the kind of lawn your neighbors will envy.

Water on Grass Blade

Knowing the function of fertilizer and choosing the right type for your yard is crucial as well.

If you found this article helpful, take a peek at some of my other articles about lawn fertilization where you’ll learn some more tips to stretch your dollar and get better results.


Sarah’s blog, Lawn Chick, is read by over 2 million homeowners each year and she is regularly cited as an expert source of lawn care knowledge by major publications. Her goal is to meet you where you are, and help you achieve a yard you’ll be proud of. Ready to take the next step toward improving your lawn? Grab her free lawn care cheat-sheet: What to Do When - Take the Guesswork Out of Lawn Care, or upgrade your garage by browsing her favorite DIY lawn care products.

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