Permaculture Basics: Using Sheet Mulch to Eliminate Bermuda Grass

Permaculture Basics: Using Sheet Mulch to Eliminate Bermuda Grass: Tried and True Methods

After moving into a home with a half-acre overgrown yard in May 2013, I am going to share how to control Bermuda grass using sheet mulch, aka "Lasagna Gardening."

Year One:  Bermuda grass filled the planters around the foundation, and English Ivy had crept into the roof.  Birds were nesting in the rain gutters and the ivy completely concealed stairs leading to a root cellar door.  Fortunately the home had received a new roof before being foreclosed on, and the inside needed only minor upgrades.

The following spring I determined where the Bermuda grass was coming from. My next door neighbor has a Bermuda grass lawn, which has spread up and down both sides of the street.  I live in Northern Utah, and Bermuda grass is considered a noxious weed in this area.

Sheet Mulch Work in progress.

Here is the best way to control Bermuda grass using the sheet mulch method:

1. Spade and turn the grass over or completely remove it.  I recommend removal for best results.
2. Add a thick layer of cardboard, then add straw and mulch as desired.  If you don't remove or turn the grass first, it will come right back in through the cardboard.
3. Dig borders and edge around the entire area, using wood, blocks, or enough rock mulch edging to block all the sunlight in order to stop the grass from growing back in. Controlling the borders is just as important as using sheet mulch. As an alternative, you can keep digging and turning the border area as the grass grows in.
4.  Use the grass you have removed as a dry mulch along fences, etc. to keep weeds down. Dug and dried before seeding the Bermuda hasn't grown back in from the dry mulch.

Simply putting cardboard over the Bermuda grass without removing the grass first didn't work.


The following spring, I enlarged the area, without digging out the grass. I simply covered the dormant grass with a layer of  heavy cardboard, straw, manure and wood chip. 
Since the grass wasn't dug or turned in this addition  the Bermuda emerged quickly as soon as the weather warmed, right through the cardboard.  It appeared the grass just consumed the cardboard and was healthier than ever. The soil itself was rich, and the improvement in the soil was evident; earthworms are abundant. This area had to be completely redone by digging the grass out and then applying the sheet mulch.

After a year, the first area where the grass was removed before applying the sheet mulch was still mostly free of the Bermuda grass, other than where the border had grown back and crept in under the wood edging.

I can't stress border control enough!  Border control is a foundational permaculture concept.  It is key to stopping the grass from growing back into planting areas. 

Original area was small square around wishing well, the front and side sections added.

The second method that has been successful for removing Bermuda grass is to put thick cardboard over the grass, and then lay heavy bags full of leaves on top of the cardboard. Then after a year, remove or dump out the bags on top of the cardboard if the grass is completely gone, or add more cardboard and or bags as needed.  I used this method in a back corner where I am creating compost piles and a chicken run. I collected bags of leaves from throughout the neighborhood for future compost and top leaf mulch.   This isn't an attractive method, but it worked nicely for a back corner of the yard, and also works well for larger areas.  It is an effective natural treatment for controlling Bermuda grass and creating a Lasagna Garden, just expect it to take time.

Use either method of sheet mulching to control grasses and other perennial weeds.

Interestingly, the Bermuda grass doesn't grow in the shade underneath large trees, and previously tilled areas are also relatively Bermuda grass free, making it much easier to control in the tilled areas.  Even if you don't want to till, tilling once in the spring and again in the fall for the first year will go a long way to prevent this persistent grass from spreading.

If you chose to apply a herbicide spray, you will need to spray more than once.  Spray once and again when growth re-emerges.  Broadleaf chemical sprays don't effect Bermuda grass, you need to use an herbicide spray. 

Enjoy your gardening, and keep Bermuda grass under control.  These tested methods were successful from my experience creating an edible landscape and reducing the amount of lawn.