Homegrown: Lawn out, garden in. Here’s how
I would like to expand our garden into a grassy area of our lawn. I can rent a sod cutter to get most of the lawn. What should I use before I plant this spring to permanently get rid of the grass?
— Sid from Centennial
You’re absolutely right to be thinking about getting rid of the grass before expanding the garden.
Stripping the sod out with a sod cutter makes it look like the grass is gone, but if your grass consists of Kentucky Bluegrass (which about 95 percent of the lawns around here are), it will resprout from underground stems.
The easiest way to get rid of it is to spray the grass before stripping it out with an herbicide containing Glyphosate. Most independent garden centers carry a product called Kill-Zall that has it. This herbicide is absorbed through green foliage and is moved down into the plant to kill all of the underground parts.
The only problem is that you may need to wait and put in your garden later than you planned. You want to spray the grass after it has started growing in the spring, usually mid- to late April.
You can speed things up a bit by watering the area well the first week of April (and maybe even fertilizing as well). That is before we usually get irrigation water so it may mean dragging the hose out there and hooking it up to your domestic water.
Once the grass is greening up and growing well and after you’ve sprayed with herbicide, I’d wait a couple of weeks to give it a chance to move completely into the plant and to make sure pretty much all the grass is dead. If it isn’t, spray a second time and wait two more weeks.
Once you’re sure it’s dead, strip the sod out and you’re ready to get going.
If you don’t want to wait that long, go ahead and strip out the grass. Just understand that you’ll have grass sprouting up in the new garden and you’ll have to deal with it then.
You won’t be able to use the Kill-Zall in a vegetable garden, it’s not labeled for that use.
If you’re planting flowers, you can use it.
You want to be careful to only spray the weedy grass and to keep it off of your desirable plants. This product doesn’t have any soil activity where it can be absorbed through the roots so it should be safe to use around existing ornamental plants.
In a vegetable garden you have a couple of choices.
The first is to dig up the patches of grass that sprout up in the garden. Be consistent with it this year and you should pretty much have the problem licked.
The second choice involves mulching. Putting down a layer on top of the ground helps prevent weeds from sprouting. Bluegrass is more tenacious than most, so I’d use a special method of mulching. Putting down a layer of newspaper is surprisingly effective.
Put down three to five layers of newspaper on top of the soil around your garden plants. You can wait to put it down after your plants are planted or the seedlings have a chance to grow. You definitely don’t want to put the newspaper over areas you’ve seeded as the seedlings won’t come up through it.
You also need to put a layer of straw, wood chips or compost over the newspaper. This protects it from drying out and blowing away as well as cushioning the newspaper so you don’t poke holes in it when you walk over the area.
This method isn’t perfect; there will be a few sprouts of grass that will make their way through. When that happens, use that first method I mentioned