Save yourself a lot of work. First determine how wide your beds will be... I favor larger beds, because it reduces mowing, gives more room for putting smaller plants and bulbs in front for more continuous bloom and color as the season progresses, and allows for gentler curves around the corners of the house. Mow the area as close to the soil as possible. Cut the existing sod along the edge of the intended bed, creating a V-shaped trench that will be a barrier to the grass, which will want to creep back into your new garden. Buy a roll of mulching paper or newsprint, (or just use newspaper or cardboard) and unroll it along the foundation, making cuts in it to accommodate the plantings. Overlap the layers a bit until you reach the trench, and pin it down with wire - I use wire clothes hangers cut about 6" long. Don't make the mistake of putting things too close to the house, you want to allow yourself access behind them, at least for a few years, to allow for proper training and pruning as they grow into the space. It also reduces potential damage to your siding if it is painted or susceptible to abrasion. Once the paper is laid down, plant your purchased plants through the paper, and cover with the mulch of your choice. In a few months, the sod underneath will die from lack of sunlight. In the future, you can brush aside the mulch and cut through the paper to add more plants, sink bulbs, or expose soil to plant seed. After a year or so, the paper will have decomposed, and the grass should no longer be viable, requiring you only to maintain the mulch, and avoiding the complication of herbicides. When I lay mulch, I try to have the soil that will be covered in the condition I want the mulch to maintain, at least in terms of temperature and moisture, because the mulch will act as an insulator for both. Tilth is less of a problem, it will improve simply because of the action of the decomposing sod and the microorganisms in the soil.

wow that's interesting. I never concidered just leaving it and covering it up :) So using this method wil get rid of the pesky weeds like wire grass? That's pretty nifty. We are planning to shape the beds with treated 2x6's or maybe 4x4's. so maybe that will discourage any creeping that may occur. If I plant things like bulbs in the area as well do i need to cut a bigger hole to allow several blades of the plant comeup... or will it make it's own hole bigger. I would hate to discourage the spread of bulbs and roots since some of these are cuttings from my own Iris' that are several years old (from the back yard).Is there any need to put in additinal fertilers or plant the new plants with additinal soil or manure? I've also seen something called "the pill" for plants that I concidered buying but I'm not sure if it will help or harm the situation. (or be of no use). I know I am full of questions, but I do appreciate your quick answer. Now I can get to work this weekned! Yay!

Is there any need to put in additinal fertilers or plant the new plants with additinal soil or manure?

Probably not. I'd plant them and see what happens. If they show signs of a problem, then figure out what you need.

I agree. Most ornamental plantings are far more forgiving of soil conditions than vegetables are. If you use paper, your bulbs and other plantings should muscle their way through without trouble. Cardboard is a little more problematic. Do a little searching here and on Google on Lasagna gardening and sheet composting for further ideas on this method. The key is to prevent the existing vegetation from growing through the mulch (hence the paper "barrier"), or into the bed from the edges (hence the trench). Remember that unless your timbers are near to the level of the lawn, you will need additional trimming - a typical mower won't cut to the edge of a wooden frame. Many stoloniferous grasses will just laugh at a 6" barrier.

I agree with Billme.

smothering existing grass is the easiest way and the organic matter from the decaying grass is good food for the soil.

Depending on which grass covering it with newspaper, or cardboard, is the easiest means of creating a new planting bed, but some invasive grasses, Quack Grass, Bermuda grass, St. Augustine grass, should be totally, roots and all, removed with good barriers placed between the grass and the planting bed to keep new growth out.
Once the new planting bed is created, or maybe before, a good, reliable soil test can be of help since most plants do grow best with a soil pH of 6.2 to 6.8 and a balanced level of nutrients as well as a soil well endowed with organic matter that is evenly moist but well drained.
Your North Carolina State University Cooperative Extension Service offers a good, reliable soil test.
These simple soil tests might also be of some benefit.
1) Structure. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. A good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top.

2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains� too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.

4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell.

5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

Here is a link that might be useful: NCSU CES

Thanks for all of the help! We are going to get to work this weekend buring the 4x4's and laying carboard and mulch. I think I'll use mostly cardboard and use some newspapers in the places where I plan to have the iris' and some bulbs. My husband loves to weedeat so i don't think there will be a chance to those little buggers to climb over. One last question and I'll hush... how thick should the mulch on top of the carboard optimally be?

The mulch should be thick enough to weigh down the paper and exclude light, but not deep enough for rodents to tunnel in unobserved. 2 inches should be plenty.

wonderful! Thanks again for of the info!

The mulch tends to compress and settle so I usually start out with a healthy 4 to 6 inches ... it will gradually settle, compact and decompose... and of course you will need to top it off with more mulch every couple years... or more depending upon what you use to mulch with.

There's a nice article in the FAQ section on how to create a new bed without tilling. (Similar to what has been described here.) Link at bottom of message.

What I like about this system is that by smothering your existing grass and weeds, you're basically composting them in place--providing natural fertilizer.

When I did this, I just cut holes in the cardboard with my trowel when I was ready to plant--worked great for me.

Good luck and happy gardening!

Here is a link that might be useful: How to prepare a bed without tilling