Dandelions are not native and were brought by the colonists, hence they have been around for a long time. Many survivalists eat them, of course, but I don't think you can use them all up that way. Dig out or poison, if you can go that route. You will need to check your soil. You did not say if it is sunny, but probably it is, and most sites as that are better planted in the fall, after you are able to kill all the grasses and weeds. Go to the prairie forum and see what they recommend if you have a sunny site. And welcome to this native site, too.

How large is your area you want planted, and what "shape?"

How much sun does it get?

What kind of soil do you have?

What climate zone are you in?

These questions will help determine the proper steps for you to take in area prep. Small areas can be mulched heavily and the seeds sown on top of the mulch. Large areas benefit from a one-time application of an herbicide like Round-up then having seeds sown with a cover crop of annuals. You will still have to remove the worst of the weeds until you get your area established.

The key to your success will be choosing the proper plants for your climate and sun needs.

Hi, bill. I hope you are not in a hurry. To do it right and get a successful results, site preparation is key.

Its commonly recommended to kill all vegetation in the area for an entire growing season before planting the natives.

It would definitely be helpful to know how large of an area you intend to plant. For small areas, smothering is the preparation of choice. For large areas, most people use herbicides.

The wildflowers are very slow to start, so the goal is kill everything to minimize competition. IF you do it right, the third growing season after planting is when you really see those results that you have been waiting for.

I think dandelions are a separate problem from removal all vegetation. You should remove dandelions at the start, but they will surely appear anyway. Your options include simply letting them grow (maybe the default option is nothing else is feasible), pulling those that you can (works on a small area, wait 'til it rains), or perhaps spraying in the early spring when dandelions may be green but nothing else is going yet (spot spray with Roundup is what I would try). In any case, you will never have a dandelion free field. Fields of nutrient poor soil, once established with strong vegetation, will not be good places for dandelions to sprout from seed, but rich soils, and particularly any disturbed soil, sill always support a few dandelions. Luckily they are not particularly invasive.

The area is rather large, around 25'x50' in one area, and behind that, scattered around some trees, an area about the same size. The first is next to a quanset hut, and runs north/south with lilacs on the other side. It get sun midday. The other area has more sun, with a couple of spruces. This area borders a farmers field (no weeds there!). There are too many to dandelions to spot spray. If I use roundup, I will kill the grass as well.
I am in zone 3, in the Red River Valley of northern MN. I am thinking of just throwing other seeds down. Maybe kill the dandelions with a general weed killer, then seed next spring?
I am always in a hurry, but I guess this one requires patience. Uh-oh
Thanks

If the grass is not native grass then don't hesitate to kill it. Native wildflowers would grow better with native grasses than with non-native grasses. You need a little research as to what species are native to your area. I would be tempted to mow the area very low, wait a week and then hit it with Roundup and then do it again a few times over the summer and then sow some seed in fall and see what pops up in spring but this is not necessarily what is best for your area.

Here is a link that might be useful: Prairie Nursery

I have heard that laying down clear landscaping plastic not only kills all vegetation beneath but also kills weed seeds down to several inches below the surface. Of course, then you have to pull up all that plastic. Also, this isn't feasible if you have trees around, because the plastic would suffocate the roots.

What I did for the meadow portion of my garden was to lay down newspaper (4-6 sheets thick) with 2 inches of leaf compost on top of it. Some weeds have occasionally poked through, which I've killed with boiling water or Round-up. Putting down all that newspaper is hard work for a large area, though.

If you choose to use a plastic mulch to kill vegetation and seeds, use black instead. Clear gets hotter, but also allows growth of some vegetation, kinda like a really hot greenhouse.

I have done amelachier's way with small areas. It is very effective if the newspaper or even cardboard is thick enough.