Do You Water After Fertilizing Your Lawn? (And How Often?)

You look outside and notice that your lawn is starting to look a little bedraggled. You head down to your local nursery, grab a few bags of fertilizer, head home, and have just chucked it on, when it dawns on you, “I forgot to ask them if I need to water this.” Luckily, the answer to the question “do I water after fertilizing my lawn” is below!

You should water your lawn after fertilizing. There are two primary reasons for this. 1. When you lightly water, you provide the vehicle needed for the fertilizer to move off the grass blades and into the soil. 2. By removing the fertilizer from the leaves, you prevent lawn burn from occurring. 

That is really all there is to it. But the next questions are just as important, how much water? How often should I water? Does one type of fertilizer differ from another in watering? These and similar questions are all addressed when you have a proper lawn care routine in place.

Watering After Fertilizing Your Lawn

Most fertilizers, once applied, require you to water within 48 hours of the application. The deviation from this rule is when there are herbicides added to the fertilizer, in which case you need to wait for 48 hours before watering. Many fertilizers come with specific watering instructions on the bag, which give you an idea of what to, more or less, expect.

When speaking about fertilizers, it makes sense to divide them between granular and liquid fertilizers.

For most granular fertilizers, immediate light watering is recommended. This “light” watering helps the granules break down and release the nutrients into the soil. Watering also helps to transport the nutrients to within range of the plants’ roots.

A light watering means that you water until the soil is wet, but puddles do not form, and run-off has does not occur. The amount of water required to reach this point of saturation depends on the existing soil moisture content, the type of soil and the season. This type of watering usually takes around 20 minutes.

When granular fertilizer clumps together on the ground, it can lead to lawn burn. This is a type of chemical burn caused by the salts found in fertilizers. These salts absorb water from the ground and the plants themselves (through the leaves). By watering, you break apart these clumps and supply enough water for the salts to absorb without damaging the plants.

As a rule of thumb, after using a liquid fertilizer, you should wait until the fertilizer dries. This usually takes between two and four hours. The reason for the delay is to prevent unnecessary “run-off” and wastage of the fertilizer. 

Many lawn care experts recommend pre-watering your lawn before fertilizing. This can be done either a day or two ahead of time. Once the grass has dried, the fertilizer can be applied, followed by another light watering. This pre-watering helps prepare the soil, “lubricating” the pathway for the nutrients, which improves distribution through the soil.

On the market are a vast amount of fertilizers to choose from. They all, however, serve a similar purpose, to put certain, specific nutrients into your soil that plants (in this case grass) need to grow. Below is a table comparing some popular fertilizer brands.

Fertilizer name	Fertilizer Type	Pre watering required?	Time delay before watering
Miracle-Gro Lawn Food	Powder-based	Dilute in water	Used in conjunction with watering
Scotts Turf Builder	Granules	Yes	Immediately
Epsoma ELF20 Organic Lawn Food	Granules	No	Immediately
Simple Lawn Solutions Balanced Lawn Food	Liquid	No	Within 24 hours

Maintaining a good watering regimen after fertilizing:

Once the fertilizer is on, and the initial light watering has been done, your lawn should be watered as per your lawn care routine. The goal is to water deeply (between one and two inches of penetration) as infrequently as possible, i.e., once a week or split up over two days for 45 minutes to an hour. 

The actual amount of water needed by your lawn will depend on factors such as season, climate, the type of grass planted and soil type.

Setting Up A Proper Lawn Care Routine

When to put fertilizer on, how much, when to water, how much, when to cut your grass and how? All these questions are very valid, and to have a lush, healthy lawn need to be answered to satisfaction. 

However, to try and have these on the back of your head every time you get five minutes to enjoy in your garden after a long day/week at work is really not ideal. For that reason having a lawn care routine and plan is the best way to ensure that your grass looks stupendous at any given moment, without expending extra headspace to it!

A good lawn routine involves:

Watering and Fertilizing: 

To grow plants require a few certain macro and micronutrients, sunlight and water. Water is essential for all life on the planet. When watering, the type of soil we have plays a big role in the frequency. The amount of water is between one and two inches of water per week. This watering can be split up into two separate waterings or done once-off and usually lasts between 45 minutes and one hour.

Try and water early in the morning as much as possible, as this allows the most amount of water penetration before the heat of the day evaporates it.

Plants will require nutrients additional to what the soil provides them. This is when we use fertilizer. The specific type and ratio of the fertilizer will be determined by what your plants require, but for the most part, nitrogen, phosphorus and potassium (NPK) will be key. 

Fertilizers are usually applied during the growing season (spring, summer and fall), between March and June, or September to October, depending on the type of grass. 

Applications are generally a half-a-pound, to one pound per 1000 square feet, done three to four times a year.  If you are using a fast-release nitrogen fertilizer, you can apply it every four to six weeks during the growing season. If the fertilizer is a slow-release nitrogen type, then six to eight weeks between applications.

Mowing/Cutting:

A lawn should be cut to be maintained at the height of one to one and a half inches long.  This is usually every two weeks in spring and every week in summer. 

When you cut, you should try and remove around one-third of the grass’s current height, any more and you could do damage to the grass. After fertilizing, it is recommended to wait at least 24 hours before cutting the lawn to not re-disperse the granules. 

It is best to mow the lawn when the grass is dry to avoid digging into wet soil with the lawnmower.

It is a good idea to leave some of the grass clippings on the lawn. These will decompose and release valuable nutrients back into the soil and help prevent water from being evaporated too quickly.

Can You Over Water Or Over Fertilize A Lawn?

You can both overwater and over-fertilize your lawn. 

The best way to tell if you are overwatering is to feel if your lawn “squishes and sloshes” a few hours after watering. If you water more than once or twice a week for a period longer than 45 minutes, you are most likely overwatering your lawn. This could result in your grass dying off.

In the case of over-fertilizing. If you start to have an influx of weeds, you see patches of yellowing grass, browning leaf tips, or very little to no growth after fertilizing; you are most likely over-fertilizing. 

Fortunately, both of these issues are rectifiable. A slight change in management practices should be enough to fix an overwatering/fertilizing situation if caught early.

Remember, timing is everything!

Conclusion

Proper lawn care can be quite an art. Although the science behind it can be quite bewildering, the basics are all we really need to focus on. Ensuring we have an established lawn care routine will help us consistently water, fertilizer and mow our lawns to perfection.