Why Water After Fertilizing And For How Long | Lawn Care

The pride and joy of every homeowner lie in the beauty of their lawn. The lush, dark green turf welcomes family and friends to gather, relax, and enjoy the coolness and comfort of the home. 

In addition, a well-tended, well-manicured lawn adds value to the property and the neighborhood. It can be aggravating when your lawn is not lush, has weeds, or is patchy. Fertilizers are helpful tools to correct the issues of a less than desirable yard and keep it as the slice of paradise it should be.

While there is not much difference in the overall effectiveness of granular fertilizer and liquid fertilizer, there are differences in how and when to water after fertilizing during the application process. Noting these differences can help you greatly improve the appearance of your lawn.

Why Water Lawn After Applying Fertilizer

Watering the lawn after applying fertilizer serves several purposes and benefits your yard and the surrounding ecosystem. Although you may think watering activates the fertilization process, it is more about getting the nutrients down into the soil and avoiding possible damage to or pollution of the fragile water sources nearby.

You will need to water your lawn to get the fertilizer off the grass blades and into the soil, where it becomes useful in the roots. How soon to water after applying fertilizer depends on the type of fertilizer you use, whether granular or liquid fertilizer, which I’ll cover later.

Another critical reason to water your lawn after applying fertilizer is to protect excess fertilizer from entering the local water supply and natural watersheds. Lakes, ponds, rivers, creeks, and other surface water sources should be considered delicate areas that must be protected. 

The chemicals in fertilizer can upset the balance of these ecosystems if they are not applied correctly. When recommended, watering your property can help prevent surplus chemicals from polluting these waters.

Although the chemicals in fertilizer do occur naturally in and around bodies of water, too much nitrogen and phosphorus can cause algae and other aquatic vegetation to grow too rapidly. They are plants, after all, and will respond to fertilizer as your lawn does. 

This imbalance of nitrogen and phosphorus will eventually lead to an overabundance of decaying plants in the waterways, which depletes oxygen levels and harms fish and other wildlife.

Watering in Granular Lawn Fertilizer

Granular lawn fertilizer can and should be watered quickly after application to get it off the grass and into the ground. The fertilizer is not valuable for the plant in its fine, solid form.

Once it has begun to dissolve in water, the plant receives nourishment through the root system. You will only need to use about a quarter to half an inch of water saturation over the area to push the fertilizer to the soil level and allow the plant to absorb the nitrogen. Watering to the point of runoff will just wash your fertilizer away along with your money, time, and effort.

Granular fertilizer, once wet, will dissolve in 24 hours or so. However, if you use a slow-release formula with a polymer coating, the complete process can take up to three weeks. Therefore, immediately watering the granular lawn fertilizer is to move it from the blades of grass and into the soil, where it can begin strengthening your lawn’s root system.

Should You Water After Applying Liquid Fertilizer

With liquid fertilizer, there is a distinct difference. Allow approximately 2 to 4 hours for the liquid to dry before watering. There is nothing to dissolve, and the leaves and blades could burn.

It is important to note that if you are using liquid fertilizer, you should consider the time of day you will be applying it to your lawn. Early morning would lessen the chances of the grass burning than if the fertilizer was applied during the heat of the day. A cloudy day would be better than a sunny day.

Keep an eye on your lawn. Watering as soon as the liquid fertilizer is dry is ideal and lessens the chances of excessive runoff or burning the delicate grass blades.

When To Water a Lawn After Fertilizing

After the initial watering of your lawn upon fertilizer application, you’ll want to postpone thoroughly and deeply watering the property for a day or two. Again, you do not wish to cause the fertilizer to runoff. 

When you water your lawn, it’s best to water it in the mornings when the temperature and winds are at their lowest; between 5 AM and 9 AM would be a good time. 

This timeframe will allow the water to soak into the soil, and thus the roots, before the day’s heat can evaporate most of it. You don’t want to water late in the day since prolonged wetness on the blades overnight can encourage disease and fungus growth.

How Long To Water Lawn After Fertilizing

After the first application of fertilizer, you only want to get the nutrients to the soil and roots, which is about ¼ to ½ an inch of water. It should only take about 15 to 30 minutes to reach this saturation level with good water pressure and a sprinkler or soaker system.

After a day or two, you’ll want to water the lawn to the point that the soil is saturated to 4 to 6 inches below the surface. That measures out to be about 1 to 2 inches of water over the surface of the lawn. You should estimate approximately 30 minutes per ½ inch of soil depth.

Plan for about 1 to 2 hours of total watering time with a sprinkler or soaker system. This will help the root system grow more robust and the runners healthier as they spread across your lawn. Don’t water again until the yard shows signs of dryness.

How Often To Water Your Lawn After Fertilizing

You will only need to water your lawn when it shows dryness and stress. The first signs are the blades turning a bluish color, appearing dull, and beginning to curl or roll upon themselves. At this point, you’ll want to evenly water the lawn to prevent unsightly brown circles and dead spots.

The frequency in which you’ll need to water your grass depends on several factors. The type of soil, climate, and weather only affect how often watering after fertilizing needs to occur.

Sandy soils need to be watered more often, like every two or three days, since sand doesn’t hold water well. As the weather turns hotter, you may need water every other day, especially in hot, dry places.

Clay soil may only need watering once every week since it holds water well. However, watering too much can cause root rot. You’ll also need to ensure clay soil doesn’t become too dry and hard. If it does, roots can become damaged in the dense, dry clay.

No matter the soil type, be sure to take weather and climate into account, too. For example, when the weather is hot and dry, you may need to water the turfgrass more frequently. 

These will be particularly true if you have noticeable changes in your usual weather patterns. For example, a hotter than typical summer, a lot more rain, or an unexpectedly long dry spell will affect how often you need to water your lawn. 

Too much or too little water will stress out your lawn. If you’re confident it will rain, adjust the water you use accordingly. 

Setting up a schedule or using timers to water your lawn can be particularly helpful if you are very busy. Just keep in mind to check the weather forecast to make adjustments to your lawn care plan.

What If You Don’t Water After Fertilizing

If you don’t water your lawn after fertilizing, you may cause more stress on your grass. As the granular fertilizer begins to heat up in the sun, it will start to burn spots on the leaves. Liquid fertilizer will also burn the blades as it warms up. What’s more, the fertilizer is for the root system, not the blades themselves.

How Long will Fertilizer Sit on Lawn Without Watering

The fertilizer will lose nutrients within two days if not watered, especially in dry weather. After that, the fertilizer doesn’t have what the lawn needs in the correct amounts. So if you spend the time, energy, and money fertilizing your property, make sure you follow all the steps.

Fertilize Before Rain Is Forecast

Natural rainfall is already full of nourishments. Fertilizing just before a gentle rain is forecasted can be an excellent way to maximize the benefits to your lawn. Otherwise, the nutrients will be in danger of getting washed away, and your turfgrass will not receive the full benefits of the fertilizer if the rain becomes a deluge.

If hard rain is in the forecast, wait for a day or two after the storm. Apply fertilizer while the ground is still wet, then lightly spray the grass to push the granules off the blades and onto the soaked soil.

Final Thoughts

Watering your lawn after applying fertilizer is necessary for critical reasons. First, the application of water pushes the fertilizer below the tender blades of grass so they don’t burn when the chemicals heat up in the sun. It also activates the process of dissolving and diluting the beneficial chemicals absorbed into the soil for use by the root system.

Finally, watering helps prevent excess fertilizer from being washed away by heavy rains and contaminating local surface waterways.

Fertilizer applied correctly includes the application of water as an essential part of the process. If you take the time and effort to give your lawn the nutrients it needs to build the turf you desire, adequate watering is a crucial factor. 

FAQs Water After Fertilizing

Now that you know why it’s important to water your lawn after applying fertilizer, read on for some commonly asked questions.