How do i a make a vegetable garden in a raised bed currently full of tall grass?

The first answer gives a good way to smother the existing grass and weeds but I would not make lasagna as she said. It can take quite some time to decompose and become compost. It will not be loam. Loam is a term used to describe soils that are approx equal parts of sand silt and clay ( a farmers dream). Compost is great, but if it is still composting, which it probably will be in the spring, it can rob precious nitrogen from the compost and your plants will not do as well. Go to a good landscape supply yard and find good soil rich in organic matter. A couple yards should do it of about $40/yard. If you need to still make a raised bed, use untreated wood that is rot resistant such as cedar or redwood.

Create a new gardening bed without tilling or pulling up grass and weeds:

Once you have a well defined garden bed, no need to clear it of grass or weeds, just layer about 6 or 8 newspaper sheets or cardboard over the bed area, water the paper or cardboard to the soaking point (this method will eventually smother whatever is growing there).

Over this paper or cardboard, you can build up layers of organic materials by using already made compost from your own pile or bought in bags from a nursery, chopped up leaves, grass clippings, chipped up prunings, produce trimmings, aged manure (not dog or cat), whatever you can gather that will rot. Pile it on as thick as you can and be sure it is kept well moistened as if you are watering a garden each week. This is known as lasagna gardening.

Or you can mix everything together and then pile it on top of the paper or cardboard if you prefer.

If you would like to have a top layer, wood chips can often be found at your city's Parks & Recreation Dept., or you can check with your local nurseries. This will make a good top dressing to keep moisture in and to keep wind from blowing away your lasagna.

This material will break down and become a rich, loose loam. Keep adding to this each year and you will have a very nice gardening bed.

First totally clean out the grass and all vegetation. Pull or dig or use a product like RoundUP. Depending what area you are in, the grass etc. will die over winter and then just remove it.

Thoroughly loosen the ground before planting. Consider fertilizing the ground for good growth. You might also want a product like Preen to keep weeds from coming up. Check the label to be sure it won't keep the seeds you are planting from coming up. Sometimes, I wait until my seeds have come up and then put Preen on ground. Enjoy your garden.

The "dealt with timber" they're speaking approximately is that dealt with timber dyed eco-friendly. this is dealt with with preservatives and pollutants which incorporate chromated copper arsenate that's arsenic. " the objective of incorporating preservative chemical components into timber products is to make the timber poisonous to the organisms that would ordinarily devour it, and as a effect improve its useful provider existence." the U. S. Public wellness standards state that even with the undeniable fact that vegetables grown next to dealt with timber incorporates an quantity of arsenic the levels are tolerable. The toxicity of painted timber on the different hand count on the form of paint used. There are some paints that are inert, some very poisonous. If the form of paint is unknown it must be greater secure to make use of that timber someplace else. a ingredient observe: A neighbor placed painted timber in my backyard to hold up the framework of our raised vegetable direction and all of it flaked off into the soil and under no circumstances did fall apart, regarded destructive so I had to do away with and replace the right-soil.

Check out:

http://ourgardengang.tripod.com/lasagna_gardening....

Hope this helps.