For cool season lawns fertilizing in the fall is the most important time to fertilize. But what most people don’t understand is that it’s the “winterizer” step that is most important. This step occurs when the lawn is building up it’s root system to survive the winter.
To properly winterize your lawn you’ll need to get the timing right. When the temperatures start to cool the grass will slow down top growth. At some point it will stop completely. This is the time to fertilize. That’s because the roots begin storing nutrients before dormancy begins.
Because the window is so small, and because temperatures are low, it’s important to use a synthetic fast release fertilizer. I prefer to use plain old urea, but you can use the Scotts Step 4 Winterguard. The key here is to not use something slow release like Milorganite for this step.
You’ll want to apply a full 1lb per k of nitrogen. If you are using Urea (46-0-0) you’ll need to apply a little over 2lbs per k to get the right amount of nitrogen. (2lbs at 46% = 0.92lb N). It is important to water it in, so you can get it down to the roots.
If you have a sprinkler system you’ll want to winterize it as well. If you have a large enough air compressor you can do the sprinkler blowout yourself, otherwise you’ll want to hire someone to do it. Failure to blow all the water out could result in ice in the lines, breaking the lines or sprinkler heads.
There you have it! Everything you need to know on how to winterize your lawn. I hope you see that it really isn’t hard. You can save a lot of money if you do it yourself.