How Much Water Should You Mix With Fertilizer?

Before using fertilizer, it’s essential to know precisely how to prepare it – if you use too much water, the product won’t be concentrated enough. On the other hand, using too little water makes the mixture more concentrated than it should be. So, how much water should you mix with fertilizer?

You should mix around one gallon (approximately 3.8 liters) of water with one or two tablespoons of fertilizer. Although this is the general estimate, it’s always best to read the instructions on the fertilizer packaging to know precisely how much water you should use.

The rest of this article will discuss how much water you should mix with fertilizer in greater detail. It will also discuss if it’s always necessary to mix fertilizer with water in the first place, if it’s OK to water plants after fertilizing, and the best water-soluble fertilizers.

How Much Water Should You Mix With Miracle-Gro?

You should mix one gallon (3.8 liters) of water with one tablespoon of miracle-gro all-purpose plant food. However, if the fertilizer is for indoor plants, you should only mix half a teaspoon with one gallon of water.

It’s essential to follow these guidelines when using Miracle-Gro products because using too much fertilizer can cause problems with your plants down the road.

You should also be aware that there are plenty of other Miracle-Gro fertilizers. Some of them need water, and some don’t. You don’t have to mix any amount of water with Miracle-Gro products that don’t need any, such as the fertilizer spikes or Shake ‘n Feed.

How Much Water Should You Mix With Jack’s Fertilizer?

You should mix one gallon (3.8 liters) of water with one tablespoon of Jack’s fertilizer when feeding outdoor plants. When feeding indoor plants, mix a gallon of water with half a teaspoon of fertilizer. This is the general measurement for most all-purpose fertilizers.

The Jack’s All-Purpose Fertilizer is prepared the same way as the Miracle-Gro one that I mentioned earlier, so no matter which one you choose, the measurements will be the same. 

Of course, if you have to fertilize many plants and an extensive amount of soil, you may need to use more than a tablespoon of fertilizer and a gallon of water. For example, you may have to mix two gallons of water with two tablespoons of product to cover everything; however, the ratio always stays the same. 

If you’re unsure of how much you’ll need, it’s best to start with a small amount and mix more later on as needed. That way, you won’t end up wasting valuable product. This can be especially important when it comes to fertilizer, which is often pricier than you’d think. 

And if you’re using Jack’s fertilizer, you’ll need to apply it once every 1-2 weeks, so you’ll probably go through the product pretty quickly.

Do You Have To Mix Water With Fertilizer?

You have to mix water with fertilizer if it’s a water-soluble product. However, many fertilizers can be applied directly from the packaging, such as Miracle-Gro’s Shake ‘n Feed. If you don’t know whether to mix water with your fertilizer or not, check the instructions.

Most standard all-purpose fertilizers need to be mixed with water, and you’ll generally need one gallon per tablespoon of product. However, when it comes to fertilizers, you can choose between a wide array of options, each with different instructions. Therefore, I’ll discuss some of them below and whether or not it’s necessary to mix them with water.

Fertilizer Spikes

Fertilizer spikes are solid spikes packed with nutrients. You can place them directly from the packet into the soil, so there’s no need to break them up and mix them with water. These products are made to be inserted into the ground as they are, so adding water would dilute the nutrients, making them less effective.

Granular Fertilizer

Granular fertilizers are commonly spread through a spreader device. You don’t need to mix granular fertilizer with water. Instead, you can apply it directly to the soil. 

Some of these products may need to be incorporated into the soil by hand after being applied. An advantage of using granular fertilizer is that it’s easy to store because the ingredients and salt content remain constant, even in cold weather.

Water-Soluble Fertilizer

You may have guessed from the name that water-soluble fertilizer needs water to work. Many of the fertilizers you can buy online or in stores are water-soluble. They generally need to be mixed with one gallon (3.8 liters) of water (per tablespoon of fertilizer). 

You can use water-soluble fertilizer for outdoor plants, indoor plants, shrubs, and trees.

Do You Need Water for Scotts Fertilizer?

You don’t need water for every Scotts fertilizer, but you need it for some of them. An example of a Scotts fertilizer that needs to be mixed with water is the Super Bloom fertilizer. However, you don’t need to mix the Scotts Lawn fertilizers with water. Instead, you should place it in a spreader.

Usually, some Scotts fertilizers (and other branded fertilizers) have “water-soluble” written on the packaging. This indicates that the product needs to be mixed with water. Then, when you read the back, the label will tell you exactly how much water you’ll need.

If you use a water-soluble fertilizer by Scotts, you’ll also need a watering can. This will make it easy to mix the product and apply it evenly over your soil.

Should You Water Plants After Fertilizing?

You should water plants after fertilizing if you’ve used a dry fertilizer. However, if you’ve used a water-soluble fertilizer, you should wait at least 24 hours until you apply more water to the soil because you want to avoid waterlogging and other similar issues that stem from overwatering.

Since fertilizer has a high salt content, it can dry out the soil. That’s why you should always water the soil right after using a dry fertilizer, such as granular. If your soil is arid (due to hot weather, for example), you can also water it before fertilizing to ensure it remains hydrated.

In some cases, particularly if the soil is experiencing drought, you can water plants after using a water-soluble fertilizer. However, this is only necessary in cases of severe dryness and drought. Still, it’s best to avoid fertilizing altogether during periods of drought. 

This is because the process can hinder growth and worsen the drought, which you certainly want to avoid.


You should mix one gallon (3.8 liters) of water with one tablespoon of fertilizer in most cases. However, it’s essential to check the packaging of your fertilizer for more specific instructions, as measurements may vary. You won’t need as much fertilizer for indoor plants.

Although some fertilizers need to be mixed with water, many don’t. Granular fertilizers and fertilizer spikes are both varieties that you can apply directly to the soil without mixing water in.

It’s good to water plants right after fertilizing with dry fertilizer. However, applying water right after using water-soluble fertilizer is not usually necessary.

If you want to learn more about fertilizing indoor and outdoor plants, you can read my other here: How to Fertilize Indoor & Outdoor Plants (Ultimate Guide)

Alexander Picot

Alexander Picot is the principal creator of, 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.

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