How Much Fertilizer?

Have you gone to the local garden center and grabbed a bag of fertilizer and when you bring it home, you get your spreader out fill it up. Then, you need to set your spreader to the right setting.  Most bags have spreader settings for a select few types of spreader, but you don't have the exact type that they have listed on the bag. So what do you do?  Guess? Please don't, too much fertilizer can burn your lawn. Regardless if they have your spreader or not, you will want to calibrate your fertilizer spreader to get an accurate application.

Well, to get the correct amount of fertilizer applied to your lawn there are essentially 3 things to take into consideration:

Take notes for each step that you do, so that you don't have to repeat it every time.

1. Swath: There are a couple ways to do this, but in the most simplistic form, put a little fertilizer in your spreader and go about 10 feet at a steady pace.  Measure the effective width.  You will take the width and then determine what distance you need to walk in order to get 200 sq ft. If you have a width of 10 feet, you have to walk 20 ft. If the width is 8 ft, you have to walk 25 ft.

2. How much fertilizer do I apply?  On each bag there are 3 numbers such as 24-10-10, the first number is the Nitrogen.  To determine how much fertilizer should be applied per 1,000 square ft, take 100 divided by the percentage of nitrogen.  Say your bag says 24 percent nitrogen you should apply 4.17 lbs/1,000 sq ft.  Since you're doing a 200 sq ft test area, that is 1/5 of 1,000 you want to take 1/5 of the weight.  So, you would place 0.83 (4.17 divided by 5) pounds in your spreader for the test.

3. Calibrate your rotary spreader:  I have an Earthway rotary spreader and I would start out by referring to the owners manual to get the suggested settings because that should at least get me in the ballpark of the application rate per 1,000 sq ft. However, it depends on how old your spreader is and how well you maintain/clean it. Do the test, if there is fertilizer in your spreader, you need to increase your setting.  If it was empty before the end of your distance, then reduce the setting. It's a little trial and error until you have the right amount, but it's definitely worth it as you want to make sure you get the appropriate amount of fertilizer on your lawn.

So that you don't have to do this test again, make sure you record your findings and the setting.