As a seller of natural liquid fertilizer, we get tons of inquiries about how to apply it and how much to use. While the application rate varies depending on the product, the way liquid fertilizer is applied is fairly universal. That said, there are at least three ways you can apply liquid lawn care products, so we’re going to do a multi-part series on the most common liquid fertilizer application methods: hose-end applicators, ready-to-use fertilizer spray bottles, and fertigation systems.
Applying Liquid Fertilizer with a Hose-end Applicator
Using an adjustable hose-end applicator is a great way to control how much liquid fertilizer you apply. However, even with the right application settings, the amount of fertilizer applied to your lawn will also depend on how fast you move. You can use trial and error to find the rate sprayer setting and application speed, but that can result in too much or too little fertilizer being applied. For more accurate application, try one of the two following methods.
Most liquid fertilizers will provide an application rate in ounces per 1,000 square feet. Most hose-end sprayers allow you to adjust the rate of ounces of product mixed per gallon of water. So, you need to know how many gallons of water are required to cover 1,000 square feet with your particular sprayer and walking pace.
Determine the Number of Gallons per 1,000 Square Feet
- Set the hose-end sprayer at 1 ounce/gallon.
- Collect the water that is sprayed over one full minute (use a 5-gallon bucket or a few gallon buckets).
- Measure the amount of water that was collected in one minute.
- Determine the amount of time required to walk through 1,000 square feet of your lawn. Walk at the pace you would while watering and be sure to cover the entire area in roughly 6-foot swaths.
- Multiply the time needed to cover 1,000 square feet by the amount of water collected in one minute to determine how many gallons of water are required to cover 1,000 square feet.
- Make adjustments to the flow rate as necessary.
For example, you fill one gallon bucket in one minute and it takes you two minutes to walk 1,000 square feet. 1 gallon/minute x 2 minutes/1,000 square feet = 2 gallons/1,000 square feet. This means that if the recommended application rate for the liquid fertilizer is 3 ounces/1,000 sq ft, setting the hose-end applicator at 1.5 ounces/gallon will ensure that 3 ounces of product will cover 1,000 square feet when you apply it.
If that’s a little too much math for you, try the following method.
Use Smart Trial and Error to Apply Liquid Fertilizer
Calculating the exact amount of water required to cover your lawn can be time consuming, and perhaps a little confusing. If you just want to jump right in, try this:
- Determine the rough square footage of your lawn in 1,000’s of square feet. Let’s say 8,000 square feet as an example.
- Determine how much product is required to cover the whole area. If the recommended application rate is 3 ounces per 1,000 square feet, you would need 24 ounces of product to cover an 8,000 square foot lawn. This is the same as 3 cups.
- Add 3 cups of liquid fertilizer to the hose-end sprayer container and set the sprayer to 1 ounce/gallon.
- Apply the liquid fertilizer to about a quarter of your lawn and stop. See how much product you have used – ideally you should have used 6 ounces and have 18 ounces remaining.
- If you have not applied enough liquid fertilizer in the area you just watered, you can go over the area at a faster pace. If you have applied too much, either walk faster on the next portion of the lawn, or change the sprayer to a lower setting.
Remember, you can also use this trial and error method with plain water in the sprayer container so you don’t waste any product or mistakenly over-apply. Always check the recommended application rate on the label and follow manufacturer directions.