May 6, 2022
How Fertilizing Before Rain Could Do More Harm Than Good
Lawncare seems pretty straightforward on the surface:
- let grass grow
- water it
- mow it when it gets too tall
However, to get a great-looking lawn that you’ll be proud of (and will be the envy of your neighbors), it takes more than that. Terrific turf takes time, tools, and TLC.
One of the biggest tools in your quest to grow the perfect lawn is fertilizer. However, you can’t just toss it out and hope for the best. Timing is everything. And when it comes to fertilizer, one of the biggest questions we get about it is: “Should I fertilize before it rains?”
So in this post, we’re here to help simplify some of the common questions about when to apply fertilizer to get the best results.
Why Should You Fertilize Your Lawn?
Let’s start with the big “why” before getting into the “hows.” Fertilizers are collections of minerals designed to break down after they’re applied to the soil in order to release valuable nutrients to plants.
The grass that makes up your lawn is a plant like any other. (Actually, your lawn is made up of thousands of them, and a big lawn could be in the millions.) In fact, turfgrass is the largest irrigated “crop” in the United States, according to a study by the journal Environmental Management featured in Business Insider in 2016.
Since all plants need the right amounts of water, oxygen, and nutrients to stay healthy, your lawn is no exception. If your soil conditions are good, your grass may be able to take in a lot of the nutrients it is looking for without much involvement from you. But if your soil is anything like the heavy clay common to north Texas where we are, anything you try to grow will need some help.
While there are 17 nutrients essential to all plant life, most types of fertilizer contain some combination of 3 basic main ingredients:
- Nitrogen (N)
- Phosphorus (P)
- Potassium (K)
You’ll find the ratio of these 3 nutrients listed in that order on the side of the fertilizer bag to let you know how much of each is in there. Nitrogen (N) promotes green leaves (or lawn). Phosphorus (P) leads to root and flower development. Potassium (K) works to improve the overall health of the plant.
Here’s the “why” behind fertilization: Over time, nutrients leach out of the soil and need to be replenished. Even the best soil will eventually stop producing strong and healthy plants if you don’t regularly apply fertilizers.
Should I Fertilize Before Rain?
When it comes to applying fertilizer, people want to know if it’s ok to put it out when they hear that rain is in the forecast. That seems like it would be a good idea since most fertilizers are activated when they get wet.
The answer is “it depends.”
Yes, it’s true that you need to be prepared to water your lawn after applying fertilizer in order to move the nutrients from the fertilizer pellets down to the roots where the grass can take it in. If you have an irrigation system, that’s a great way to do it, and you don’t need to wait for rain.
However, if rain is predicted after you intend to spread fertilizers–it doesn’t matter if it’s granular or liquid—you want to be careful about how heavy the rain is expected to be. A gentle shower is great. A Texas “gully washer” is not.
Will Rain Wash Away Fertilizer?
The problem with fertilizing just before heavy rainfall is that the water won’t have time to slowly filter down into the ground and deliver the nutrients where they need to go. Instead, it will simply wash your fertilizer into the nearest storm drain.
As these fertilizers (along with other chemicals, pet waste, and grass clippings) make their way into local water systems, they create water pollution that damages the natural balance of those ecosystems. Commercial properties have to be especially careful since parking lots only move water and excess fertilizers that much faster.
Is It Good to Fertilize After It Rains?
Generally speaking, it isn’t best to fertilize after it rains, but you may still be able to get the fertilizer to activate with the remaining moisture on the soil surface. It could be your only option if no other source of water (an in-ground irrigation system or a large sprinkler) is available. Be sure to allow the blades of grass to dry thoroughly before applying any chemical fertilizers, though.
When Is the Best Time to Fertilize Your Lawn?
Spring and fall are the best time of year to fertilize. That is when lawns are actively growing (depending on the type of grass). The best time to fertilize your lawn within those seasons is when you can turn on an irrigation system immediately afterward or when a light rain is predicted. For fertilizers to benefit your lawn, they must get wet, but not so much that runoff occurs.
If you are using your irrigation system to water in fertilizer and notice that water is beginning to flow through the yard and into the street or storm drains, turn the system off and allow the water to seep into the soil. Then wait a few hours before watering any more.
As a side note, never apply fertilizer when extended drought conditions are expected. It won’t do your plants any good; you’ll waste money on fertilizer because it will eventually become inactive, and whatever is left will simply wash away in the next big rain.
Take the Guesswork Out of Fertilizing. Trust It To Us.
We’ve been servicing lawns in Dallas, Fort Worth, and surrounding areas for over 20 years now. Our lawn care professionals understand how important a beautiful lawn is to you, and they have the knowledge and experience to apply the right fertilizers and just the right time to get the results you deserve.