A few weeks ago I wrote about preparing for crabgrass control by using pre-emergent herbicides. Many of these herbicides, as well as many fertilizers and fescue seed, can be applied to your lawn using spreaders. These devices are fairly simple and are powered by the forward push of the operator.
There are two main types of spreaders. Drop spreaders are preferred on very small lawns and on areas that require precision application. They only dispense the pesticide or fertilizer in the area directly underneath the bucket. Broadcast spreaders are the most common for home lawns. They throw the product out in several directions, making application quicker.
Many different companies sell broadcast spreaders. Each has their own unique way of labeling for application rate. Your spreader may have settings from 1 to 5 or 1 to 10, and you have to rely on finding a bag of herbicide or fertilizer that shows the correct setting number for that brand of spreader.
Some products you will purchase will not have your brand's application rate on the bag. Instead, the label will give you a rate, usually in pounds per square feet. You may need to know how to calibrate your spreader to figure out your specific application rate. To do this you will need your spreader, sand, a bucket, a tape measure and a bathroom scale.
First, set your spreader one-third of the way open. Put a few pounds of sand in the spreader and walk forward for 20 feet. Measure the width of the swath of sand being applied by the spreader. Stop and measure the swath width, then remove the sand. If you have a drop-style spreader, your swath width will be the width of the bucket. Divide your swath width into 1,000. Record this number.
Next, place 10 pounds of the product you want to use into the spreader and operate the spreader for the number of feet calculated in the last step. After walking that distance, stop and remove the remaining product from the spreader and weigh it. Subtract this weight from 10 pounds. The resulting number is the number of pounds of the product applied per 1,000 square feet.
You can now adjust your spreader settings up or down and repeat the process to achieve the desired application rate for specific products. Once satisfied, be sure to make a note or mark on your spreader which settings are correct for which product.
Application rates for home lawn products are very important. They keep us from wasting money by applying too much or not enough seed, herbicides and fertilizer. They also help us limit our environmental impact by applying only the amount of product that is needed. Use this simple calibration method to help you care for a better looking lawn this year.