Can I simultaneously kill off grass and sow wildflower seed?

Question

I'm planing on establishing a fairly large area - 1000 sq ft - as a sort of wildflower meadow. The area is currently lawn with pretty good quality soil. I live in Asheville, NC zone 6.

Here is my question: I have established wildflower meadows by seed before and have always cleared the area of existing grass and weeds before sowing the seed. My tiller is not currently operating and I really don't feel like hand digging the whole area to remove grass, so here is my plan. I'll cut the grass super short and add a thin layer of compost to the area. I'll sow my seed onto the compost and compress with a roller. I will then cover the area with cardboard for two to three months (until grass is sufficiently dead) into the winter. I will then remove the cardboard at the beginning of spring or earlier and hopefully be left with no living plants but a nice wildflower seed bed. I will be sowing the seed in a few weeks so it naturally stratifies over the winter.

Will covering the seedbed with cardboard for a few months affect germination negatively? I'm aware some flower seeds require light for germination, however, if I removed the cardboard before spring, then it should be fine yeah? I'm interested in hearing what ya'll have to say about this. It would sure save me a lot of work!

Here are the species included in the mix I will use.

Annual Baby’s Breath, Annual Phlox, Black-Eyed Susan, Clasping Coneflower, Corn Poppy, Four O’Clocks, Gayfeather, Gilia, Indian Blanket, Lemon Mint, Lance-Leaved Coreopsis, Leavenworth’s Tickseed, Moss Verbena, New England Aster, Perennial Lupine, Plains Coreopsis, Purple Coneflower, Scarlet Flax, Scarlet Sage, Sulphur Cosmos and Tree Mallow.

Answer 1

I thought of doing the same on a piece of land I own. I thought a lot about it, and now I finally got the chance of building a new house on that property. So what I'm thinking now is I'll wait after the digging machines are done with their job, wait they put back the earth in place and put the seed afterwards.

I tried it on someone else property where I saw the bull machines operating: I offered them the seeds and went there in spring with my little rake. Great results, see below.

So my advice here is instead of killing with chemicals (which I absolutely hate especially if you want wildlife there afterwards), is you ask a peasant around if she could run her plowing machine. Then you can spread the new seeds.

Beautiful result:

Answer 2

Go rent a sod cutter. Easy peasy. You can then take the sod and turn it over to make some softly rolling plant beds so it isn't just flat. Get some top soil and cover all with a couple of inches and roll. Or use the sod for plant beds around your foundation (watch for drainage back into your foundation keeping sod, soil, gravel 4" below siding 2" below bottom of fences). Wait to seed in the spring unless you live in a mild winter area and you know what seed you are using.

Another solution would be to cut out 'sweeps' leaving a path of lawn or a lawn patio to place a few chairs and a table to sit among the flowers. Add a small patio tree or an umbrella. Use the sod turned over to give some definition and height to the wild flower 'sweeps'. Find a few chunks of grayed picket fencing and place behind the little seating area. Erect a handsome scarecrow with a wheelbarrow overflowing with wildflowers. That will give your area a 3rd dimension instead of being 2D. Go find some ornamental grasses to give movement when there is a breeze. My favorites are Mexican Feather grass (this will probably reseed itself), Maidenhair grass, for 'walls'. Perhaps a 'sweep' of dwarf fountain grass. Always do natural 'clumps' or 'sweeps' of a grass or allow it to be a partial fence.

What you are thinking of doing just won't work. Can't kill and grow new stuff at the same time. And rethink taking up all of the lawn. Make that area a place people would like to putz in, entertain a guest, read a good book. Otherwise it is just a plot of wildflowers to look at from a distance.