Should You Water a Lawn After Using Weed and Feed?


Weed and feed is an effective product that functions as a broad herbicide and fertilizer. Using such a product is a convenient way of tackling the care and maintenance of your lawn. However, you must use the weed and feed correctly to be effective. 

You should not water a lawn immediately after using weed and feed. Instead, wait for at least 24 hours. Ideally, wait about 2-4 days to ensure that the fertilizer has been released and absorbed by the lawn.

This article will explore why you must wait before watering your lawn after applying weed and feed and when to water the lawn after using the product. The article will also detail how to use weed and feed, so read on. 

Why Wait Before Watering a Lawn After Using Weed and Feed?

To understand why you must wait before watering a lawn, you first need to understand how weed and feed products work

Weed and feed combines two very different actions, which take place one after the other. First, the herbicides attack any weeds present in the lawn. These herbicides work to prevent weeds from sprouting in the first place and are very good at managing specific weeds like dandelions and chicory. 

The fertilizer is only released after the herbicide has started working, so it needs time to be absorbed. The fertilizer in a weed and feed product will typically be rich in NPK – the three plant macronutrients. 

Watering the lawn too early will wash the product away before it can perform its functions, cancelling out the overall effectiveness and wasting the product.

In addition, pesticide and fertilizer runoff is a big problem and can contaminate groundwater. It might even harm your children or pets.

When To Water a Lawn When Using Weed and Feed 

When using weed and feed in your lawn, timing your watering can help improve the product’s effectiveness and prevent accidental runoffs or plant burns. 

Here’s when to water a lawn if you’re using a weed and feed product on your lawn. 

Water Before Application

Water your lawn deeply and thoroughly a day before applying weed and feed on your lawn. A well-watered lawn can withstand the high salt concentration that comes with a dual application of herbicides and fertilizers, so you won’t end up burning the turf. 

Wet soil will also allow the product to stick to the weeds and the grass more easily, which increases the product’s overall effectiveness. The water will allow greater product mobility through the soil, letting it kill even the deepest-rooted weeds. 

Remember to water your lawn in the early morning so all of that moisture will be absorbed properly. You can learn more about the best time to water your lawn in my article discussing whether you should water grass in direct sun: Should You Water Your Grass in Direct Sun?

Water a Few Days After the Application

After you’ve applied the weed and feed, wait at least 24 hours or as much time as the packaging recommends. Waiting gives the product time to work and be absorbed by the lawn. 

Ideally, you should wait up to four days before watering your lawn in, or as long as it takes for the weed and feed to dry. 

This is especially true if you watered your lawn a day before applying weed and feed. Most turfgrasses prefer to be watered once or twice a week. Watering them immediately the next day after using an herbicide/fertilizer mix will lead to overwatering and potential runoff.

While waiting for the next watering session, don’t allow your pets or children to play on the lawn, as they might accidentally ingest the weed and feed. 

After the product has dried on your turf, you can thoroughly water your lawn again, allowing any remaining product to flow into the lower roots to kill the weeds and fertilize the grass. 

The Right Way To Use Weed and Feed for Your Lawn

Weed and feed is an extremely convenient product that reduces the time and energy invested in your lawn care. However, using it correctly will go a long way in ensuring that you actually manage to help your lawn instead of hurting it. 

Choose the Right Product

There are a number of weed and feed products in the market that are well-rated by people who’ve used them and are known for being effective. However, you must only use the products that suit your lawn

Check the type of grass that grows on your lawns and the kind of weeds you frequently spot growing with them and compare them with those listed on the product’s packaging. 

For instance, one of the most popular brands of weed and feed is the Scotts Turf Weed & Feed, (available on Amazon.com). This weed and feed is known for being extremely effective without burning your lawn. Scotts Turf Builder works on several common weeds, including clover. However, you may want to check the product label for plants that you cannot use this on. 

Always read the product label carefully to ensure that the weed and feed you pick is right for your lawn. 

Time Your Application

As weed and feed combine two products, you need to apply it at just the right time, so you kill any weeds before emerging but don’t accidentally hurt any turf in the process. 

Early spring is one of the best times to apply weed and feed as this is when weeds seeded in winter start sprouting. Your turf could probably use a nitrogen boost around this time as well. 

Pick a time when it’s not raining. You don’t want to apply your weed and feed and watch it all get washed away if it rains soon after you’ve applied the product. You may apply the product a day after a light shower or 2-3 after a heavy downpour. Check the weather forecast to make sure it won’t rain again within a few days of application.

On the other hand, you should also avoid applying weed and feed in times of drought and heat stress, as your turf will get burnt. 

Get the Right Tools

Get yourself the right tools to broadcast your weed and feed evenly and accurately throughout your lawn. Liquid weed and feed products can be applied through sprays, while granulated weed and feed products may need rotary spreaders

Most products will detail the tools needed for application on the label, so follow the instructions exactly to ensure proper application. 

Mow and Water Your Lawn

Once you’ve got your product lined up, mow your lawn a few days before so it’s at a comfortable height. You want your grass to be taller than 2 inches (5 cm), as anything less than that can affect the turf’s ability to photosynthesize. 

Then, water your lawn a day before you apply your weed and feed to allow your grass to be hydrated and give the product something to stick to. Preparing your lawn in this way ensures that the product will be effective without damaging your lawn. 

Be Careful With Your Application

Weed and feed products can be harmful to other plants and trees in the garden, so only apply your weed and feed to your lawn, and keep away from the drip line of your trees. 

Only use as much product as mentioned in the packaging. Typically gardeners use less product than recommended on the packaging when using fertilizers. Remember that it’s easier to add more fertilizer than to revive a plant suffering from fertilizer burn. 

If you haven’t seen any weeds in your lawn over the last season, don’t apply a weed and feed. Indiscriminate usage can lead to salinity and toxicity buildup in your soil, affecting the health of your turf.

Final Thoughts

You can water your lawn a day before using weed and feed to help the product stick to the weeds and the roots of your grass and be more effective. After using weed and feed, wait at least a day before you water your lawn again. Ideally, wait about four days or until the product dries completely to give it time to work.

Make sure that you’re using the right weed and feed for your lawn, and be careful to only use as much as is necessary.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

Recent Posts