[centipeedoff]

I've scoured the internet to try and find someone with a similar situation to this without much luck.

Situation:
My parents live on a saltwater creek in Morehead City, NC. Their lawn is probably close to .4 acres and is made up primarily of St. Augustine, some Centipede, and a new visitor near the creek named Bermuda.

Basically, my father brought in some soil to fill in some low places near the water which seems to have had some bermuda seed in it. What started as sharp, wiry grass near the water has turned into a lush, bermuda mini-lawn. Their yard floods roughly 1/3 the way up pretty frequently with the high tide and the whole yard will usually be under during a hurricane. The part that floods has had the st. augustine killed off and is now almost exclusively bermuda.

It's actually pretty remarkable. I knew bermuda was very drought/sunlight tolerant but had no idea it does so well under four-six inches of brackish, salt water.

My mom loves the bermuda, and would like to see it cover the entire yard. I told her it's an alpha grass and is waging some pretty solid war on the st. augustine and visa versa.

Question:
Can these two grasses coexist? What does a yard part bermuda/st. augustine end up like? The Bermuda has grown aggressively over the area that gets flooded. This year it's really filled in nicely, and I'm wondering if it'll continue to creep up even past where the water floods to or if the two grasses will just stalemate in the middle of the yard?

Also, Bermuda looks better cut <2 inches and their St. Augustine gets scalped pretty good at that low of a height (un-level yard due to lots of downed trees and whatnot). Should they mow the Bermuda at a lower level and the St. Augustine at a higher level? May be healthier for the grass, but in my mind their yard will be the equivalent of the bowl cut I had in middle school.

Any help or thoughts from someone with experience of this would be much appreciated.

PS: I've attached a Google-Earth image to show where the two grasses are meeting (well, not quite but you'll get the idea)

 

[cnet24]

I have some family in the Charleston area that deal with a very similar situation. I'm not sure what type of grass their lawn was originally, but at this point the high tides/hurricanes have paid a toll on their lawn and about killed it. They are too old to be dealing with the hassle anyways.

It looks like based on your diagram that the tidal areas contain bermuda. My thought would be over time the St. Aug has died back leaving nearly zero competition, so the bermuda has prospered.

I think it comes down to, what type of grass do they prefer? Is it worth it in their eyes to battle the bermuda constantly? Now that the bermuda is thriving, no doubt it will begin to take over some patches of St. Aug.

 

[Topcat]

When I bought my home, the neighbors had a rather larger Branford Pear that gave too much shade for anything except for St Aug to grow on the portion of my lawn that is adjacent to theirs, so I had a nice healthy St Aug lawn on one side of the driveway and Bermuda on the main portion of the front lawn.

They cut the tree down a few years back, and last year I noticed that the now sun soaked St Aug lawn had Bermuda invading it. SO I started nuturing the Bermuda and torturing the St Aug. I kept is a about .50 - .75" last year, and St Aug does not do well with that HOC. This year I hit it with MSMA and did an aggressive Verticut/Dethatch which made the lawn look horrible. I am confident that the St Aug will be but a memory next year. There are a few patches of St Aug left but the Bermuda is winning the war. I have about 80% Bermuda in this area.