Roundup and other herbicides are the most cost-effective way of killing turf grass, but you should be aware the Earth Goddess weeps whenever she sees them used.

Watch that wind drift.

Roundup will work -- but spray on a calm day and make sure it doesn't drift to any neighboring plants you want to keep. [Some plants are horribly susceptible to Roundup: daylilies and tomatoes, for example. I got one small drop of Roundup on a daylily, wiped it off immediately, and soon after had a dead daylily.]

If you have a place where you can use more grass, then before you spray, remove the best parts of the sod, either using a regular spade, manual sod-cutter, or rental sod-cutting equipment.

Landscape fabric to prevent future weeds isn't recommended. As time goes on, weeds will grow on top of it. Roots will grow into the fabric -- either from weeds on top of the fabric or roots from below. I have a bed with the previous owners' landscape fabric. I don't know how old it is, but it's about 2-3" below ground level, riddled with roots from the maples 15-25' away.

Now if you were asking about using plastic to kill the grass -- yes, that works; it's called solarization. I'm expanding two beds right now by that method. I do it during the winter, and it takes about two months. I buy 10' x 25' black plastic from Walmart's hardware section, cut or fold it to the right size and shape, then hold it in place with landscape staples or anything heavy (small pavers, large stones, bricks, etc.). [The landscape or garden staples are also called pins; I've bought them at Lowe's and from a garden catalog, and also made a few from old wire clothes hangers.]

Once the grass is dead, remove the plastic, then either till the old sod or remove and compost it. Either before or after you plant, cover the dead sod (or dirt if you removed the sod) with several sheets of newspaper, wet them down, then cover that with mulch to prevent most future weeds.

Good luck with the new plantings!

If you spray an area of your lawn with roundup, cut the border with a space or edger first because the rhizomes are connected to other grass in the rest of the lawn.

I'm a big fan of stripping it off, shaking out the soil and trowing it away. It is more work, but I think it is worth it. It really is not that bad and there is no extra waiting.

Just a note on nomenclature - missingtheobvious describes a method using black plastic which I have used very effectively too. It also works with old carpet. But it isn't Solarisation. It kills the grass and weeds by excluding light. Solarisation uses clear plastic and only works in sunny warm conditions. It kills the grass and weeds by heat, not light exclusion. (It also kills soil organisms both beneficial and otherwise.)

Laag's method of good old fashioned digging and shaking off the earth is another one I use all the time. But I would urge you not to 'throw away' the sod. Add it to the compost heap. Otherwise you are throwing away the nutrients that the grass absorbed during its life. Compost it and you can return them to your garden.

Really, the optimal solution is a function of the specific variety of grass involved, soil type, the area to be renovated, etc. Your county (or whatever you call counties up there) should have a staffer dedicated to providing assistance in these matters.

I am with Laag. Digging out the sod it worth the extra effort. I think we all mean compost it, as opposed to throwing it away; but thank for making that clear, flora. If you go to the effort of digging it up, you might as well remove it instead of just turning it over because the grass might come back if you turn it.

If you spray with roundup, the dead grass and its root system is still there. You have to dig it out to plant other things.

When you turn over the sod in chunks, you will need to do it partially as double-digging, so any roots do not appear. You can plant immediately in it, by 'stashing' some sod much below the surface and away from the plant. It worked for me, no resource is wasted, but it is heavy work and not meant for large areas.

What I've done:

1) Outline my beds with marking paint.
2) Plant (easier to remove grass if you can grasp it).
3) Flip over any grass that you removed from the plant hole to build a moat around various trees and large shrubs
3) Mow remaining grass to lowest setting.
4) Utilize a fine bark mulch.

The grass dies and you get the benefit of the decomposing grass. I never understood why people go through the hassle of using round-up or digging it up.
There are occsasional sprouts of quack grass but thats it.

Here are some sample beds I did.

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