Last Updated on April 7, 2021

How Long Should Fertilizer Be Down Before It Rains?

You care about your lawn. You pick out just the right fertilizer. Let’s make sure your application works as well as possible! Some concerned homeowners worry that rain will wash all that carefully applied fertilizer right out of the yard!  Is it better to fertilize before or after it rains? Read on to find out!

What happens if it rains after you fertilize?

A gentle rain is the perfect way to activate your fertilizer and help it soak into the ground. Fertilizer needs some moisture and water to move the granules down into the soil, break them down, and reach the grass’s roots. Most companies recommend regular watering after application. In fact, fertilizer on a dry lawn won’t do your grass much good and may even burn your grass. 

A heavy rainfall may be a different story, though! All your fertilizer granules could wash away during really heavy rain – which is bad for the environment. Avoid applying right before a heavy rainfall.

Is it better time to fertilize before or after rain?

Before rain

Fertilizer will be less effective if applied right before a heavy rainfall. If there is any runoff, it could wash out of your yard before it even has a chance to soak in and activate! Don’t apply it right before significant rainfall, or it (and the money you spent on it) will wash away!

Check the forecast for rain. Apply your fertilizer two days before any expected rainfall. If you apply it, and it looks like it may rain, water your yard with sprinklers before it rains. This will allow the fertilizer application to activate and soak into the soil before the rain comes.

After rain

If you decide to wait until after the rain to fertilizer, wait until the blades of grass are mostly dry.  You want the fertilizer to fall to the soil, not stick to the wet blades of grass.

Will heavy rainfall wash away fertilizer?

Will Heavy Rainfall Wash Away Fertilizer

Heavy storm water will wash fertilizer out of your yard. Rainfall of greater than ½ inch puts your fertilizer at risk. If you have hills and ditches, the chance of runoff is even greater. Compacted soil may also cause greater loss during rain. If your soil is compacted, look into aeration services for a healthy lawn!

What is in fertilizer?

Fertilizer is full of nutrients to help your lawn be thick, green, and healthy! It keeps your lawn strong during heat and cold, keeps weeds away, and helps your grass establish a strong root system.

  • Nitrogen. Nitrogen helps your lawn grow green and lush!
  • Phosphorus. Phosphorus helps roots and seeds grow strong.
  • Potassium. Potassium helps your grass and plants withstand stress, like weather conditions and foot traffic.

What’s the best way to apply fertilizer?

Most homeowners prefer to use a granulated product. Granulated fertilizer is easy to store and spread with a spreader. Make sure you have an even application. Add a gentle application of water within 24 hours to make sure the fertilizer can soak into the ground and begin to work!

Be careful not to over-fertilize with a granular application. Overfertilization can dehydrate your turf and lead to yellow or dead grass.

Some people swear by liquid fertilizers. Liquid products are a quick-release method of nutrients for your lawn and plants

Granular fertilizers are slow release.

If you are in the midst of a lawn care emergency, a liquid application may save the day! Most liquid products are applied with a garden backpack sprayer.

Always read all the package instructions. Make sure you understand and follow the directions.  Use caution when using chemicals – you don’t want to harm the environment, kids or pets.

When is the best time to apply fertilizer?

It’s best to utilize a complete fertilizing system, with different ingredients added for the different seasons and growing patterns.

In early spring, apply your first round. Use a preventative application to keep the crabgrass and weeds at bay. The best time to apply a preventative fertilizer in March or April.

In late spring, it is time for a weed and feed type of fertilizer. This will keep the weeds down but help the grass grow strong!

Apply this in May or June.

During the summer, keep your grass healthy with another application of weed and feed or a soil food to keep your soil full of nutrients and healthy microbes during the hottest months. This is typically applied during July or August.

Finally, in the fall, its time to get your lawn ready for the cold months ahead with a fertilizer with a high concentration of nitrogen and potassium. The potassium will help your grass and soil weather the cold weather and diseases.


Author: Matt Hagens

Matt Hagens

Hi, I’m Matt the owner of Obsessed Lawn. I love to be outside working on my lawn, planning my next project. I created this website to help people like you find the best products for yard care and great advice. Learn more about me and find me on Facebook.