How To Turn Granular Fertilizer Into Liquid

Liquid fertilizers are a better choice for cold weather and when you want to use a sprayer application. 

Granular fertilizers will dissolve in water and can be applied with a sprayer. Be sure to soak the fertilizer until it is completely dissolved in water. Apply the correct amount for your soil by checking the NPK ratio. 

Granular fertilizers may be easier for you to store, but you prefer to apply liquid fertilizers.

Liquid fertilizers are also recommended when the soil temperature dips below 50 degrees as the soil activity is too slow to break down granular fertilizers effectively. 

Organic fertilizers like bone meal can also get eaten by pets or livestock before they get a chance to feed the plants. 

By creating liquid fertilizers you can get the goodness into the soil feeding your plants quickly.   

How To Turn Granular Fertilizer Into Liquid

How to Dissolve Granular Fertilizer In Water

Dissolve granular fertilizer in warm water at the rate of application recommended by the product label. 

Use a dedicated container and measure your granules into the container. 

Add warm water and stir well for 3-5 minutes. Check the mixture after an hour and stir it again. 

Some gardeners notice dark material that will not dissolve, this could be iron (you can test it with a magnet), and should be discarded as it can clog a sprayer. 

If your fertilizer is not dissolving, you may need to break down the granules. You can do this by mashing the mixture to break up the chunks or by using a dedicated blender to turn the granules into powder before dissolving. 

The NPK of your fertilizer and your intended application will impact how much fertilizer you will need to dissolve in how much water. 

Dissolving fertilizer for houseplants requires only a few teaspoons to a few tablespoons while making a batch for your lawn requires cups of granules and gallons of water. 

Be sure to start with warm water as nitrogen will pull any heat out of the water. 

Pay attention to the nitrogen content of your fertilizer when dissolving it as nitrogen can burn the leaves of plants. 

If you have a high nitrogen fertilizer it is best to apply it away from the leaves of the plant. 

How Long Does It Take To Dissolve Fertilizer In Water?

Soak any granular fertilizer in water for 24 to 48 hours to completely dissolve the fertilizer. Urea, a common nitrogen ingredient in fertilizer, has a cooling effect, so start with warm water to avoid freezing. 

Depending on your application method it is important that the fertilizer is thoroughly dissolved. You can check the mixture after 2-4 hours and if it is fully dissolved it can be applied with a sprayer. 

Slow-release granular fertilizers will take longer to dissolve than crystal fertilizers like urea.

When you have dissolved the fertilizer it will no longer be a slow-release product and you will need to fertilize more frequently. 

Can I Dilute Fertilizer In Water?

Fertilizers can be diluted in water, but you should understand the math involved when you dilute a product. 

Look at the NPK ratio of your fertilizer and the recommendations for application.

For example, this bag of Scotts Weed and Feed Fertilizer has an NPK ratio of 28-0-3 so in 100 pounds of this product, there are 28 pounds of nitrogen. 

Weed and Feed Fertilizer

It is recommended that you apply about 3lbs per 1,000 square feet of this product. That means you will be applying just 1/10th of a pound of nitrogen to the 1,000 sq feet. 

Remember that the liquid will be absorbed at a faster rate than it would be as a granular fertilizer.  

So if you plan to apply it to a 1,000-square-foot lawn, you should dissolve the fertilizer in enough water to cover that full 1,000 square feet. 

Liquid fertilizers are more available to plants than granular and they also run out of the soil more quickly. You can reasonably expect a liquid application to produce faster results but require more frequent application. 

Be sure the mixture is less than 10% nitrogen to be conservative and avoid nitrogen burn.   

The burns come from over application of nitrogen to stems and leaves. Your liquid fertilizer should contain less than 14% nitrogen as a general rule to avoid nitrogen burns.  

Whenever possible avoid spraying leaves with liquid fertilizers. A drip irrigation system can be a great way to apply liquid nitrogen fertilizer. 

Can I Dissolve Fertilizer in Water?

Most fertilizers will dissolve in water if given enough time, agitation, and heat. Organic fertilizers like bone meal, kelp, or compost tea may need to be strained before using them in a sprayer. 

Liquid nitrogen is incredibly cold, so if you are dissolving a granular form of nitrogen you need to start with very warm water to avoid freezing. 

If you are having trouble dissolving your granular fertilizer you can use a blender to break down the granules into a powder then dissolve the powder in warm water. I recommend that you use a blender that will not be used for food in the future. (Grab one at the thrift store or this affordable one on Amazon.) 

Making Your Own Liquid Fertilizer

Liquid fertilizers have a lot of benefits for plants and for the gardener. If you are looking for a liquid fertilizer you have a lot of options. 

Here are three ways to make your own liquid fertilizer:

Dissolve Granular Fertilizer

Granular fertilizers are easier to store and often less expensive than liquid fertilizers. 

You can dissolve granular fertilizers in warm water to create a liquid fertilizer that you can apply to plants while doing regular watering. 

Remember that fertilizers are often formulated to be distributed over a large area, so if you will be dissolving water to fertilize it should be sprayed over a large area. 

If you are looking to use the liquid fertilizer to water container plants or individual plants you should use a much smaller amount of fertilizer. 

When dissolving granular fertilizer for lawns you can dissolve at a high rate of up to a pound in several gallons, but for watering container plants consider 2 T in a gallon. 

Soak Manure

One way to make an organic liquid fertilizer is to soak chicken manure or other dried manure at a rate of 1 part manure to about 5 parts water. 

Allow this mixture to soak for 48 hours to two weeks. It should be the color of tea. 

Strain out any solid and apply with a sprayer or watering can. 

The composition of the fertilizer will depend on the manure used, refer to this extensive study on NPK in manure to get an idea of what you have. 

This method is outlined more extensively in Mother Earth News in an article on all types of ways to make liquid fertilizer. 

Banana Tea Fertilizer

Banana peels can be used to create a high phosphorus liquid fertilizer. This is a good safe liquid fertilizer for flower plants that benefit from the high phosphorus. 

To make this liquid fertilizer, put your banana peels in a bucket and cover them with water. Allow the mixture to sit for 48 hours or more. 

The resulting tea can be used to water flowering plants or plants in nutrient-poor soil. 

The peels can then be added to the compost or blended into a paste and used as a side dress fertilizer. 

This is a great way to fertilize roses or garden flowers.

Dissolving Fertilizer Granules Into Liquid Fertilizer Pros and Cons

When you change the form of the fertilizer it does change how it is used by the plants. 

Granular fertilizers are formulated to release slowly over 2 or more waterings while applying these same fertilizers as a liquid will release all their nutrients to the plant at once. 

This means that you may want to dilute the fertilizer so that you are applying it at half strength to compensate for the fast uptake. 

You will also need to fertilize more frequently as the liquid will run out of the soil much more quickly than a granular fertilizer would.  

High nitrogen fertilizers can burn leaves in both liquid and granular forms, but be careful not to create a very high nitrogen fertilizer when you dissolve your granules as that can cause nitrogen burns. 

Granular fertilizers are often less expensive than liquids making it easier to keep them.

Liquid fertilizers that are commercially available are generally already diluted with some water making them less powerful than granular fertilizers. 

Applying liquid fertilizer when watering saves time over applying dry fertilizer after watering the lawn. The time saved is important to some gardeners. 

Drip irrigation systems are also a great way to get your fertilizing and watering done all at once. 

Fertilizers that are intended for these types of systems can be very costly, but if you know how to recreate these NPK ratios with an off-the-shelf granular fertilizer you can save a lot of money.