Looking for a natural way to remove turf from part of your property? Establishing a pollinator habitat or a garden bed means getting rid of the existing lawn. So, how can you kill grass permanently without using nasty chemicals?
Natural ways to kill grass
These three methods are sure to eliminate grass with no harsh chemicals. Which one is right depends on your situation, including how much grass you need to kill, how fast you want it to happen, and how much labor you’re willing to do.
1. Solarizing
Solarizing takes advantage of the sun’s energy to essentially cook your grass to death. In most of North America, this process takes about two weeks. In hot, sunny locations less time is needed.
How solarizing kills grass
Solarizing takes advantage of the sun’s energy, usually by covering the ground with a transparent tarp. The sun heats up the soil to extreme temperatures. This can kill turf roots, and can also be damaging to bacteria and fungi. In fact, solarizing can even destroy weed seeds and insects, leaving the area almost totally free of life for a clean-slate.
Solarizing produces steam in the soil, which can quickly reach high temperatures and damage most forms of life, killing your turf. Sandy soil can be difficult to solarize because the steam escapes more easily.
How to solarize your grass
The first step of solarizing is to remove as much of the grass as you can. Mowing it very low is ok, but for the best results you should till and pull all the clumps you can get.
Next, water the soil deeply. Then apply the tarp or plastic. Clear painters’ plastic is the best option. Remember, you want sunlight to get in as much as possible!
The tarp should be buried along the edges to trap in heat and steam. This should also be done during the hottest part of the summer for the best effects.
Solarizing can take four weeks or longer, so be patient before removing the plastic. You may need to add water throughout the process if your area is in a dry spell.
This process will kill ALL seeds in the area. So, don’t count on an ecosystem springing to life when you pull away the plastic. You may need to add compost to replenish the biota in the soil.
2. Sheet composting
This approach takes the most labor of the three, but is also the fastest and most effective way to unturf. With this approach, your grass is smothered instead of being cooked.
How sheet composting kills grass
Sheet composting is sometimes called lasagna composting, because it is done in layers. Frequently, yard debris or tilled grass is considered the bottom layer of the lasagna, while topsoil or composted soil is added as a top layer. A barrier, such as a sheet of cardboard, is the lasagna noodle.
To kill grass, sheet composting relies on the concept of smothering. Your grass should be covered by something that it cannot grow through or around. If it can’t get to sunlight, it will die. People sometimes attempt to smother grass with an opaque tarp on the soil surface, similar to solarizing. This is not effective and will not unturf your lawn.
To smother grass effectively, the barrier needs to be left in the soil. But leaving your tarp underground is probably not a great plan. Cardboard and newspaper make a decent biodegradable barrier. And that barrier will last long enough to establish new plants above it – especially with the addition of topsoil and compost.
It is also a good idea to till or disturb the grass before beginning. And you can add more soil in the second and third years.
How to sheet compost your grass
This process is fairly simple, with only three steps. For an in-depth explanation (with a video), check out How to Sheet Mulch Your Lawn.
3. Natural grass killer (liquid grass killer)
If you need a precise touch to kill grass showing up where it shouldn’t, this approach is best. Instead of using harsh chemicals to kill the unruly grass (or other weeds), use a mixture of natural products that damage the grass.
How natural chemicals work and how to use them
Different chemicals work in different ways, and some may be more potent than you expect. So, be careful and do some research before mixing anything too noxious in your lab (or kitchen).
Some common natural approaches to weed-control that you can consider include:
- corn gluten
- acidic natural compounds (like vinegar or citrus)
- salt or dissolved minerals
- extreme heat (boiling water or torches)
Organic science can get very complicated when it comes to chemical alternatives. Find something that works for you and your conditions. It can be very helpful to find local organic groups.
The best way to kill grass
Each of these three methods has its place in getting grass out of our landscape. Combine these three approaches to ensure success with any grass-removal project. The best way to kill grass is to replace it with a native ecosystem! Over time, grass will not survive where it is not competitive. So, create the conditions for native plants and they will thrive.