1. Know your lawn: what type of sod do you have growing out there anyway?
Most of the people in our SB Turf "normal" delivery area (ie, the Pee Dee, and Coastal areas of South Carolina) have warm-season turfgrass, like Centipede, St. Augustine, Zoysia, or a hybrid Bermuda, like 419-Tifton. If you are totally unsure of what kind of sod / grass you have in your yard, it is a good idea to find out from a professional. Your HOA might know, too. You could even ask your home builder.
BUT... If you apply a nitrogen-containing winterizing fertilizer to your Centipede, St. Augustine, Zoysia, or Bermuda in early - late Fall in our area of SC, you are most certainly doing more harm than good. Our warm-season turfgrass friends get injured from the effects of fertilizers that contain nitrogen when they are going into dormancy.
Just because the neighbors are using it doesn't mean you should. Aunt Sue up in Michigan is winterizing her lawn, but that doesn't mean you should. Those pretty packages of interesting little granules might be better left right there on the shelf, instead of on your yard.
There are usually 3 numbers on fertilizer bags that are separated by dashes. Something like 10-10-10. The first number indicates the amount of Nitrogen in that particular fertilizer bag. Some may have this printed on the outside of the bag: TURF BUILDER | GUARD AGAINST WINTER | WITH WEED CONTROL | FOR WINTERIZING YOUR LAWN .... No matter how pretty the outside of that bag looks, know what you are buying. The Clemson Extension (an independent co-op that does not make a profit off of you) advises that if a soil test shows that your soil is low in potassium, you may want to amend this issue by applying a muriate of potash or potassium sulfate. Wait! Don't go running out to the home and garden stores yet! The Clemson Extension ALSO SAYS that if your lawn has had a regular regimen of spring - summer fertilization using something like a 16-4-8, it is "unlikely that a fall application [of potassium] would be helpful."
Be confident in your knowledge that many times when it comes to the grass in your lawn, less is more. If the slinky lawn care "professional" you have hired keeps trying to twist your arm into putting "stuff" on your lawn to get it ready for winter, tell him to take a hike. Have confidence in yourself. Trust your instincts. Why would someone tell you to put something on your lawn that would hurt it? The only answer that makes sense to me is: The Almighty Dollar. I don't think lawn care people in our industry intentionally try to mislead folks.... sometimes many of them really have never learned that grass in our part of the US does not need to be winterized in the fall. It is winterizing itself. Just leave it alone and let it do its dormancy thing all by itself. Without help from you. Really.
There are some best management practices that you can incorporate in your lawn care program that will improve its overall health, thus helping it get through the winter better.
- One such cultural practice that can help your lawn is to remove the leaves from it. Trees that lose leaves signal that fall is here. They also can be trashy. There are some scientific reasons (aka proof) why getting those leaves off your lawn is a good idea -- things like the turf's ability to make food for itself is increased when you get leaves that block sunlight off, things like the leaves could change the pH of your soil, etc.... but one not-so-scientific reason to get leaves off the lawn is that the fallen leaves are just like trash sitting there on top of your grass. Are leaves Mother Nature's southern trashy tumbleweed, blowing across your yard? This writer thinks so.
- Something else you can do to help your grass is to figure out if you can help it get more light. Grass that is in the shade (of the house, of a tree, whatever) stays colder longer and therefore, has decreased photosynthesis taking place to feed itself through the winter. Remember, during the winter, your sod / lawn is NOT DEAD -- it is still very much alive.
- If you have a controlled irrigation system, longer waterings through the spring and summer will help to promote deeper root growth. Deeper roots mean that the soil will be able to better-insulate the roots when the freezing temperatures get here. Short, infrequent waterings may seem like a way to save water, but irrigating your lawn this way does not help it as much as watering at longer time intervals.
- Increase the mowing height you (or your lawn maintenance company) cut your lawn to as the Fall season comes upon us. Yes, that means the leaf blades on your lawn will be longer. Scalping the lawn in the Fall so you won't have to mow it anymore is a terrible mistake that a lot of people make. The benefits to increasing the mowing height are three-fold: 1) it will leave more leaf tissue on the plant to produce more food 2) it will promote deeper rooting 3) it can protect the sod from weed seeds that could possibly be germinating in the late fall.
In a nutshell, if you have sod in the low country / coastal areas of South Carolina, you probably have some variety of warm-season turfgrass in your yard. Warm-season turfgrass usually does NOT need chemical winterizing in the form of a fall fertilizer application.