Zilker Neighborhood Gardens

Commentary by a National Wildlife Steward who helps Zilker neighbors establish native plant gardens

Tag Archives: mulch

Update on Killing Grass with Newspaper

A while ago, I told you about the killing grass with newspaper and mulch method. At the beginning of March, I implemented this method in my front yard where I’m beginning to layout a semi-formal garden (more on that later). I put down the newspaper, wet it, and put several inches of mulch on top. This front yard has pretty good St. Augustine grass on it. Last weekend, I had to go through and dig out a few green grass blades that were getting through but overall, the method is working. Here’s a picture of the dead grass underneath the newspaper and mulch:

Dead grass under newspaper

So in about 5-6 weeks’ time, the grass is dying. I have not yet planted anything in the beds yet but if I wanted, I would just poke a hole through the newspaper and dig out the dead grass (which is easy to remove since it is dying) and plant a plant in it. Of course, you’ll need to do some consistent “grass weeding” until all the grass is dead and none is invading the area. To help with the grass invasion, we will be edging the bed with a sort of trench in the coming weeks. I’ll show some pictures of that soon.

One issue with this method is that it does not allow you to amend your soil. If you dig out all all the grass, you could amend the soil from the beginning. But digging is so difficult with established grass. If I wanted to amend the soil, I think I might kill the grass with the newspaper method by doing this method above. When I saw the grass was pretty much dead, I’d remove the mulch (use it in another area or put it on a tarp for use again). Then you could dig out the dead grass which is much easier to remove, amend the soil with lots of compost and other good things, plant your plants, and then put some of the mulch back on top!

How to Kill Grass

If you are going to do some gardening, you might need to get rid of some grass to be able to create a nice bed for your new plants. There are several ways to do this that (a) do not use chemicals, (b) do not cost much money, and (c) do not require back-breaking work (well, maybe some – but we all need the exercise anyway).

My favorite is the newspaper method. First, you start saving your newspapers – but not the glossy pages. Design your planting bed – you can draw it out using garden hoses, flour, and/or landscape paint. Once you like your design, pick a day that is not very windy to get to work. Lay out your newspaper on your grass – about 10 sheets in thickness over the whole area of grass. Overlap the edges slightly so that no grass pokes out. I like to wet down the newspaper a bit when I have them in the right spot – especially if it is at all windy as those sheets will start flying. Once your newspaper is down, you dump about 6-8″ of mulch on top. Then you wait about 1-2 months. If you are dying to plant, just poke a hole through your mulch and newspaper and dig a hole and plant your plant. You may get a few grass stragglers coming up, but just pull any out that you see. After 2 months, almost all the grass will be gone. I used this method in MN where I used to live, and it worked like a charm. I also recently used this method in my backyard. On hearty St. Augustine, it might take a bit longer to kill the grass but it will with time. I did buy 5 cubic yards of mulch from the Natural Gardener (about $200 delivered) and had to move it back via wheelbarrow (some work), but it wasn’t that bad. Natural Gardener has a formula to figure out how much mulch you need. I just measured the beds I planned on making and did a little math. Over time, the newspaper disintegrates into the soil. Remember, you can add shredded newspaper to your compost anytime you need “browns” to balance it out. Of course, if you can coordinate your new planting bed creation with the Christmas tree mulch the City of Austin gives away in January, then you’d save some money!

Another way is to kill grass using clear plastic. However, contrary to what you think, you do not use black plastic. Instead, you use clear plastic in order to solarize the grass (essentially, that means burn it up). The plastic also needs to be somewhat thick – perhaps 6mm. The other key to solarizing the area is that you should do this in the summer when the sun is hottest and most direct. In addition, you need to keep the grass area slightly moist under the plastic. So, occasionally you need to spray some water under there. I know that you are surprised because I was surprised when one of the presenters in my training told us that clear plastic was the appropriate method. You should find a way to keep all the edges of your plastic down (logs, rocks etc.) in order to not let “cool” air within it. The experts say this approach is best, and that clear plastic + moistness creates more heat deeper into the soil under the plastic. Of course, you can use black plastic, but it will not work as quickly as the clear plastic.

The third way, which is more backbreaking, is to just cut out your sod. You could use a flat shovel and cut out your sod (if you keep enough soil on the bottom, you could use your sod in another location on your property). You could also rent a sod-cutter and use the machine to cut the sod out. I have never used these machines, but I’ve seen them used on gardening shows on TV! Neither of these approaches are easy on the back / body. If you cut your sod, you might want to use a pitchfork or twirlyfork to mix up your soil afterwards. It is always good to throw in some compost to prep your beds. Remember – always call before your dig!

Call Before You Dig is a free service that locates your underground utilities. Use this service any time you plan to excavate at your home or business. Call toll-free (800) DIG-TESS (344-8377).

The utilities will mark any underground cables/lines so you can be careful round those areas. It is also helpful to know where your sprinkler lines are, if you have irrigation, so you don’t poke your pipes and cause a leak.

The last way is to use bad, bad chemicals. I am not a fan of this, so I won’t mention it. But think: if you are intending to build a beautiful garden of wonderful natives, do you really want to put them in the ground where you just sprayed chemicals? It’s not a very “green” choice, and the NWF Habitat Stewardship aims to promote greener ways for gardening.