Kendra Although it would perhaps be nice to rework your soil to a depth of three feet or more, this can't really be done at once. So start where you are and begin to work in your compost and available materials such as leaves. Perhaps plant a rye cover crop to dig in when comes the spring. If you enjoy digging then dig and dig deep over time, if not do the first 4-6 inches. Garden at your enjoyment level. If you don't want to dig at all, use a no till system like lasagna beds. But be realistic and build up your soil year after year and it will do fine.

Do not remove the soil you have there but amend it with compost and other forms of organic matter. You want a soil that contains about 6 to 8 percent organic matter and that would be about 1/2 inch of compost mixed into the top 4 to 6 inches of the soil you already have.
If you do use animal manures, also add vegetative waste at about 3 times as much manure and be sure the manures are there 90 to 120 days before you plant to harvest your food.
Creating a Lasagna garden may be one way to go.

Here is a link that might be useful: About Lasagna Gardening

Thank you tons Kimm, this info is very precise and helpful. Does it matter that the "soil" in the area is very sandy and has some tiny pebbles throughout it? The area is so dry.

Kendra, it also depends on what type of vegetables you wish to grow. If you want to grow a variety of carrot that is 12" long you need to prepare the soil to that depth or deeper. However there are lots of shorter varieties of carrots so 4-6" should be sufficient to start.

Sandy soil will need more organic material or you will be watering often. Mulch can help hold moisture and over time the right mulch will improve the soil. You might think about growing a cover crop in the spaces between the rows. This vegetative material then gets cut down/plowed or spaded in and will greatly improve the soil.

How big are the "tiny pebbles"? Again, that won't affect most vegetable roots except for root crops like carrots, or tubers such as potatoes. Carrots can grow misshapen if there are too many rocks in the soil. If the pebbles are more than 1" you might screen the soil just in the area you are planting. It would be a lot of work to try to remove all the small pebbles in the entire garden and they do have value in increasing aeration to the roots.

Do you know about 'double-digging'? It's something you might do gradually over a small area each year to increase the amended depth of your soil.

I've picked rocks for years in my garden but now seldom do as there are only small ones and the more compost I add the fewer small rocks there seem to be in proportion so they don't bother me (or the plants).

g'day kendra,

do you necessarily need to do all that digging work? when raised gardens will deliver the same results with no digging.

see our presentations:

our latest raised beds we are using corrugated roofing for sides.

len

Here is a link that might be useful: lens straw bale garden

Raised gardens do not magically appear, they take extra work and money.

If his soil is fertile why ignore it and build on top of it?

He should find out what his soil consists of to find out what will help the most.

I agree RpR.
If you do not have the money or time to build a man made bed, then work organic matter/compost in to the soil. A depth of 12-18 inches is best, but starting with 6-8 inches & build up a bed is fine. Adding compost & leaves every Spring & Fall, you will have a nice bed in a year or so.

Kendra, the soil I have here is Lake Michigan beach sand. All that I have done, in the 45 years of gardening here, is add organic matter to that sand and produces very well with that 6 to 8 percent that I get in that sand. This well draining soil holds moisture quite well with that 6 to 8 percent organic matter, plus mulches which help maintian the level of organic matter in the soil.
Elliot Coleman, Four Season Farm, learned about adding organic matter to soil from Helen and Scott Nearing, authors of "Living the Good Life" who raised all the food they needed to support themselves.
Get enough organic matter into your soil and it will be good.