Killing Nutgrass

If ever there was a villain in the garden, nutgrass would be the culprit.

It is one of the most hated weeds and very aggressive, robbing desirable plants of water and nutrition.   Nutgrass rankles my sister  so much she tells me she can see it out of the corner of her eye as she walks through her garden. Then, like any good gardener she attacks it and tries to dig up the whole plant along with the rhizomes and the tubers (also called nuts). Any tubers left behind will generate a whole new set of weeds.

Though it looks like grass, the plant is actually a sedge. The  varieties most often seen are  Cyperus esculentus (yellow nutsedge) and Cyperus rotundus (purple nutsedge).  Even our own garden has an unwanted plot of purple nutsedge in the Edible Garden area.

What should we do about this problem intruder? How can we kill nutgrass organically in a large garden area? *Kim Kirkhart has had success with her variation of the  loose landscape fabric method taught by Skip Richter, Texas AgriLife Extension  Agent for Harris County.

What’s  needed:

• Heavy black plastic
•  Plastic pots
• Bricks or rocks to hold plastic in place
• Time-this method takes several months  up to a  year

Recycled Plastic Pots

Begin by setting plastic pots in the garden area. The pots have a dual purpose. They  hold up the black tarp and also spot kill nutgrass. 3 or 4 pots are stacked together (turning them each to cover their holes).

As you can see, not all the nutgrass is under pots.  Don’t worry though, those invaders will die under the tarp, without light.

Heavy Black Plastic

Next lay the black plastic over the whole garden area on top of the pots. The pots keep the plastic elevated so emerging nutgrass shoots can not puncture through the plastic and let light in. Overlap the seams of the plastic to keep the light out.

Bricks hold the plastic in place, remember to keep the plastic lifted.

Carefully place bricks or rocks around edge of plastic and wait for the nutgrass to die.

This organic way of killing nutgrass requires patience. We started this process July 26 and plan to take off the plastic in October in time for fall gardening. We will let you know the results of our test!

Pictures  by *Kim Kirkhart, DCMGA class of 2006

Ann Lamb

Click here for Skip Richter’s article, Weed Wars.  We have used the expert advice in this article for our method of killing nutgrass organically.