raised garden beds directly on grass?

No, you don't need to dig up the sod. If you put several thick layers of newspaper down first, the wet it, you can put your raised beds right over top of it. The newspaper, which is organic, will smother the grass and prevent it from growing. Both the newspaper and the sod will break down over time giving more nutrients to your soil. As someone mentioned, this is a form of Lasagna Gardening. Good luck and happy gardening!

Unless your raised bed is only 4" high you dont need to strip the sod. The dirt will smother the grass. I wouldn't bother with news paper, feed fabric or anything. A weed barrier will do absolutely nothing except waste your time and money. The only reason a raised bed would give you a better yield is because the soil in the raised bed is less compacted than the ground is. As for less water needed I have to disagree. The soil will dry out faster in a raised bed so it will actually take more water. The nutrients from the newspaper is a joke. Unless you had over 4" of news paper the effects will be slim to none. Don't use rail road ties to build your raised bed because they contain chemicals that are harmful to plants.

Depending on what kind of grass it is you could just put down the frame and fill it. The thickness of the soil should kill the grass, and it will decompost and feed the worms.

You could, I would, put down a thick layer of newspaper or cardboard that will smother the grass better and decompose as well. Look for "lazania gardening'.

Do be sure the raised bed is really deep enough, at least 8 inches, bet if its like 2 feet deep.

You definitely need to use a fiber barrier between the grass and the new soil/compost for the raised beds or the grass WILL grow up and become a problem very quickly. But raised beds give a much better yield in a smaller space and use less water - so go for it!

The nutrients from the grass will nourish the bed. Unless you've really fertilized; just put the beds on the grass and enjoy the veggies. Somewhere deeper than you're loosening is some hard soils; don't worry; just plant !

I would take out the sod and put a breathable cloth on the ground where the raised beds will be.. get screened loam. And have a soil test... Don't for get to feed the little purrrties

No i haven't tried it But to get your mix to compost (and not be hot enough to "eat" your new plants will require some work on your part... You can actually get compost to fully form in 4 weeks or less but you have to achieve optimal condition. Wet but not soggy AIR (Oxygen) Heat water it and turn it daily - cover it to increase the temp good luck

If you want healthy roots,give them room to spread they-re feet,no weeds,dig baby.

This is a good question