Happy New Year, Hancock readers! We hope you’ve had a chance to check out our monthly specials, which includes big sales on all Centipede Grass Seed, beginning on Friday, January 27. If you live in the Southeastern United States, there are few grasses that are better matches for your lawn!
However, Centipede Grass is known to suffer from a mysterious condition known as “Centipede Decline,” a condition that scientists don’t fully understand. This ailment sets in on mature Centipede lawns (usually more than three years old). Symptoms include the grass dying off and being replaced by weeds. This will appear in spots, usually around a foot in diameter, but will soon expand into patches that stretch up to six feet in diameter.
We may not understand the Centipede Decline gets started, however scientists have made enough observations to get a rough understanding for what conditions lead to the condition, as well as what you can do to make sure your lawn remains mature and healthy for years to come.
Trust us...our two “cent”s is worth it in this case!
01) Avoid Pre-Emergent Herbicide
There are two kinds of herbicide that you’ll deal with when caring for your lawn: Pre-emergent and Post-emergent. As the name suggests, pre-emergents kills unwanted specimens before they can break the surface of the soil, while post-emergents are applied directly to the weed after it sprouts. Some popular pre-emergents include those applied for crabgrass prevention.
Unfortunately, the biological behavior of Centipede Grass makes pre-emergents a growth-stunter. You see, Centipede Grass spreads by sending out stolons. These are stem-like structures that spread out laterally from the plant, aboveground, before putting down roots. Most grass species spread via rhizomes, which are similar to stolons, but that travel underground.
In most cases, weeds are on their way out when they encounter the pre-emergent herbicide, failing to break through to the surface. Centipede Grass has the opposite problem: Its stolons encounter the pre-emergent herbicide and struggle to set their roots down in the soil. Limited root spread and growth makes it difficult for any grass to grow tall.
02) Mow Low...But Not Too Low!
There’s a happy medium to be had if you want to prevent Centipede Decline while mowing your lawn.
On one hand, you don’t want to mow your lawn too low. This is, once again, because of those stolons. If you set your blade too low, you’ll risk damaging the aboveground stolons, which will in turn damage the spread of roots around the rest of your lawn. On the other hand, you shouldn’t set your blade too high either—if the stolons are left to run amok, they’ll climb all over each other and prevent themselves from taking proper root.
The best bet is mowing at a height between 1” and 1.75” on a weekly basis.
03) Don’t Go Overboard With The Nitrogen
Over-fertilization is always a problem, but scientists have drawn a connection between one element of fertilization in particular and Centipede Decline: nitrogen. There seems to be a correlation between lawns that intake high levels of nitrogen and this ailment.
It’s recommended that you apply no more than four lbs. of nitrogen to 1,000 sq. ft. of your soil in any given year. Optimally you’ll spread these applications out, distributing two pounds of nitrogen during May, and then repeating the process during July.
And yes, we said nitrogen. Not fertilizer as a whole.
This is where it comes in handy to understand that not all fertilizer is the same. Take a look at any bag of fertilizer. You’ll see three letters—NPK—with accompanying percentages. These stand for “Nitrogen,” “Phosphate” and “Potash” (from “Potassium”). Different blends have different levels of each. This, unfortunately, is where you’ll need to do math.
Let’s assume that you have a 50 pound bag of 10-10-10 All Purpose Fertilizer , which is 10 percent for all three scores. Multiply the weight of the bag by the percentage of nitrogen included, and you’ll see that you have roughly five lbs. of nitrogen in that bag. So you can use 40 percent of that bag to cover 1,000 sq. ft. Hancock sells specialty Centipede Weed & Feed Fertilizer, which works to stifle weeds and promotes growth. This blend has a 16-0-8 score, which means you should use five pounds per 1,000 sq. ft. in May, and then do the same thing during July. One 50 lb. bag of our Centipede Weed & Feed Fertilizer covers ideally covers 10,000 sq. feet of Centipede Grass, in one sitting.