Hey tessica, I was in your spot 11 yrs ago. I did end up buying bags and bags of compost and some peat to start a garden around my patio. Then when I wanted a veggie garden a few yrs later, I bought plastic wood-look (Trek) planks and raised it above ground. Again, used all purchased soil, compost and peat.
If you have the time to do a compost pile, go for it. But for a fast start, I recommend buying the 'good stuff' to get you off to a head start.

I started several flower/shurb gardens using newspaper and chipped wood mulch to cover the paper. Start in fall, and by Spring, you will have a great wormy soil.

I'm sure many of the expert gardeners on this forum will have more and better ideas for you. Let us know how you proceed and what the results are. Good luck to you.
Pondy

Hi, Tessica, What fun...a new garden! I enlarged a rose bed a few years ago, but I did it the easy way. It was in an area that had heavy sod (hubby's pride is his lawn, but I told him it was less to mow). In the fall, I covered the area with cardboard with a few rocks to hold it down. In the spring, after all the snow, rain, and cold, the cardboard had killed all the grass, and I just tilled what was left into the soil.
You can google "lasagna garden" and it's about the same thing.

Blueberries are difficult in Wisconsin. Blueberries need an acidic soil and most of Wisconsin is alkaline. Get a soil test from the extension office and say that you want to grow blueberries and they can help with how much soil sulfur and peat moss you'll need to add.

As for the new garden, there are four ways that work well. The first is to lay down newspaper or cardboard this fall and put mulch or compost on top. The second is to plant into the grass in spring and put newspaper around the plants to smother the grass and then mulch on top. The third is to wait until spring and till when the weather is good and soil isn't too wet. The fourth is to use Roundup either now or in the spring or both. I've used all these methods. With any of these I still get some grass growing into the beds. What worked best for me was to till in the spring and wait a week then round up the grass that came up. That way you have soil easy to dig into and less grass than most of the other methods. I should add that the reason laying the newspaper in the fall didn't work for me was that my dogs ran through that area all fall and winter and tore up the newspaper so the grass was able to get through.

I agree that blueberries are more challenging than the average plant in Wisconsin. There actually are some counties where the soil is almost acidic enough for them, but not many. Depends where you live in Wisconsin.

If you live in the east part of the state you will definitely want to get a soil test done and ensure you find out if your soil has free lime in it. If so the amount of sulfur you need to add to acidify the soil is much greater than if the soil didn't have free lime. The lab can advise you on this.

I would likewise encourage you to contact whomever supplies your water. Many places in Wisconsin get water from limestone wells and the water is very high in alkalinity. The end result is that the pH of the soil in areas you irrigate frequently will creep upward just from the water. Adding vinegar to the water for plants needing acid conditions can help (along with sulfur).

NEVER add lime to soils here unless you have a soil test recommending it.

If your soil is predominately clay pay attention to your yard after a heavy rain to see where water ponds up, if it does at all. I would avoid planting in that area unless it's something known to tolerate poor drainage.

Can't help with asparagus as I don't have any, but this might help.

I have found that if you google on 'plant name in Wisconsin' or 'growing plant name in Wisconsin' somewhere in the first few-several results is usually a link to the Wisconsin University Extension system's relevant publication.