I think most people are aware of the role of nitrogen for crop growth. It is the nutrient that plants need in great quantity and is responsible for lush, leafy growth.
But, I suspect, that most people who fertilize their lawns with nitrogen don’t realize that half of the nitrogen fertilizer that they apply can be lost to the air!
While this may seem a little hard to believe, it has a lot to do with the type of nitrogen fertilizer that you buy and it boils down to a bit of soil chemistry. Yes, I know, you don’t subscribe to this newsletter to read about chemistry but if you read on you might save yourself a few dollars and have a better looking lawn to boot!
For lawns, nitrogen often comes in the form of compound called "Urea". Urea readily breaks down in soil and releases nitrogen that your grass can use. However, when it is applied to the lawn surface it is broken down by soil microbes who "break apart" the urea which is then released as a nitrogen containing gas called "ammonia". Up to 50% of the surface applied urea can float away into the atmosphere.
Part of the solution to the prevention of the loss of this ammonia is to incorporate an "enzyme inhibitor" with the urea which dramatically reduces the amount of your nitrogen floating away into space.
At Hole's Greenhouses, we have a lawn fertilizer with the highest concentration of nitrogen available anywhere, and it comes with an enzyme inhibitor to keep your nitrogen in the ground where it should be. It’s called Nitro Boost 46-0-0.
When Should I Fertilize?
Stay off your lawn in the spring until it is dry.
Mowing: Mow your lawn between 2.5” and 3”. Mow your lawn often, never cutting too much at a time as this causes shallow roots. Thick deep roots will make your lawn greener longer. And NEVER cut your grass stems in half.
Thatch: Thatch is the dead grass on top of the soil. Stick your finger into the soil to measure. A healthy amount of thatch is around ½”. Too much thatch prevents fertilizer from doing its job and you will need to dethatch. If you have too little thatch, stop bagging your clippings for a while to build up a thatch base of ½”.
Watering: Never water over ¾”, especially when you fertilize. Do not water in the evenings as this promotes fungus.
Fertilize: Fertilize on moist soil, not before a heavy rain. Fertilize after a rain or during a light drizzle for best results. Fertilize sometime after May long weekend if you are only doing one application a year.
SPRING: Once lawn is dry, rake, aerate and apply fertilizer.
SUMMER: Apply fertilizer every 30 days until mid-August.
FALL: Final application of fertilizer after first frost.