Our Lawn Fertilizing Service branch in Berrien County Michigan has an unique issue in that there is a large population of Zoysia grass. 

Award-Winning Lawn Fertilizing Service by a Master Gardener.  Master Gardener Lawn Care’s lawn fertilizing service receives a few calls each spring from clients in Berrien County, Michigan for Zoysia grass.

A growing problem in our area is the unwanted spread of zoysia grass.  So what is zoysia and why is it a problem?  Zoysia is a warm season grass originating in Asia ranging from China, Korea, and Japan to the Philippines.  Originally brought to the United States from the Philippine’s as a lawn grass, various species thrive along the Gulf Coast and Atlantic coast of Florida. Korean strands of zoysia work well in southern California while Chinese and Japanese varieties do up the Atlantic coast as far as Maryland.

Due to a very deep root system zoysia grass in resistant to drought although they do turn brown after the first cold blasts of the year.  In our northern states they are slow to green up.  In addition to the deep route system zoysia spreads by both rhizomes and stolons.  These are horizontal stems or shoots, below and above ground respectively, which very slowly fill in areas in which it is planted.   

When used in these warm climate area’s zoysia provides a thick green carpet of grass that requires little maintenance.  So why is zoysia a problem grass?  The three main reasons are: it is an invasive grass; in our climate it is brown for most of the season; and it is slow growing.  The last of these can actually be a benefit when trying to control zoysia in our growing zone. 

Zoyzia will not only fill in bare areas of your property, it will crowd out any and all other species you are cultivating.  After it has conquered your lot it will begin attacking your flower beds and migrating to your neighbors lawn.  

Do you like looking at hay fields?  Our cooler spring and fall weather promotes extended dormancy in zoysia grasses. Greening in mid to late June and turning brown with the first cool winds of September zoysia will provide an unsightly mess for half of our growing season. 

The problem of slow growth zoysia provides to southern growers can actually be a help to us.  With early recognition the northern home owner can spot treat at the first signs zoysia is trying to establish itself in their lawn. 

The best defense against the spread of zoysia is to establish a solid border around the area you are trying to protect.  Wide metal edging will work best; it must be deep, at least six inches below ground, and high, two or more inches showing above grass level.  This will prevent the rhizomes from traveling underground and keep the stolons at bay ass they try to creep through on the soils surface. 

When you first discover zoysia has found its way into your lawn is the time to attack.  Complete eradication is the only solution to controlling its spread.  Spot treatment with a non-selective herbicide such as Round-up will kill every plant in the section treated.  Treating a small section and reseeding the affected area will prove easier than postponing the inevitable for a few years.  Eventually the ever spreading zoysia will drive anyone who cares about their lawn into action.  When the grass has taken over a yard, drastic measures will be needed to eradicate the nuisance grass. 

In any attempt to rid a lawn of zoysia grass it is important to wait until the hot weather of July and August when the grass is growing.  This will ensure the plant is ready to absorb the herbicide.  When going for a total kill at least two applications of Roundup Super Concentrate are recommended.  The Super Concentrate will cost more but has a 50.2% mixture of the active ingredient Glyphosphate, isopropylamine salt.  After mixing the solution per directions thoroughly soak the area to be treated being sure to treat every blade.  Do not cut the lawn for two weeks.  This allows the plant to completely take up the herbicide.  After this time cut the grass and repeat the application.  After two weeks it will be necessary to decide if another application is required.  It would be a good idea to take this step now rather than assume the plant is dead.  The zoysia roots are notoriously difficult to completely kill.  Make the third application just as before and again let the grass grow.  After two weeks cut the lawn as short as possible and wait at least a week.  You will be looking for any sign of fresh growth, if none are found you can be prepping for reseeding or laying sod. 

About the Author Mark Morris is the founder of Master Gardener Lawn Care Berrien County Michigan.   Mark’s Company, Master Gardener Lawn Care, provides an organic based lawn fertilizing service in St Joseph, Benton Harbor, Coloma, Stevensville and other areas along the western Michigan shoreline.  Master Gardener Lawn Care was established in 1991 and provides lawn fertilizing service, core aeration, weed control, soil testing and insect control.  For more information on our lawn care and lawn fertilizing services or to request a free lawn care analysis please visit our Free Lawn Fertilizing Service Estimate page on the mastergardenerlawncare.com website