No, the Seedslinger is not the answer. I use this device, and have extensive experience with both it and trying to rescue prairie restoration or creation sites such as you've described. You surmise the problem. The Seedslinger wonderfully scatters the light and fluffy prairie seeds. But it doesn't get them into contact with bare soil on a site such as yours. Sadly, nothing much does. As long as there is existing dead and live vegetation there, the seeds have no way of getting into the top 1 mm of soil.

And be careful with Plateau. It's wonderful stuff (no longer available to non-governmental buyers). But unless properly applied at just the right concentration, it can have no effect, or can simply stop the growth of a bunch of forbs. I don't recommend it on seeded, growing sites such as yours.

Your greatest problem is probably the native goldenrods (Canada or tall). Here's the absolutely best way to deal wit these on a site such as yours. Watch their growth closely. Just as soon as the goldenrod plants have reached full height, or seem to have begun to harden or mature after the quick spring shoot-up, then go in and mow the entire site down to 4 inches or less. You want to force the goldenrods to expend all of their stored root energy growing the new stems and leaves. Then, you want to cut them back close to the ground. In my Ohio this is in about mid June. In your area it's probably sooner. This goldenrod mowing leaves the cut-off plants with very little growth reserves in the roots or rhizomes, but it puts the plants at the start of full summer heat, and that's very stressful for these goldenrods. The plants have to resume a compleat growth cycle once again this year, but they've already used most stored carbohydrates to power the first growth spurt.

If you mow soon, you will get way ahead of the goldenrods. Wait, as most do, until fall, and the plants will have already set down adequate root reserves for next year's growth. Slice them now and they have a difficult time catching up. In fact, to virtually eliminate them, let them regrow after a first mowing in June, then mow 'em off again in late August, before they can flower. They then get doubly behind and most can never catch up, especially with increased competition from the tallgrasses.

And mowing of the meager prairie grasses (in the second year or later) only causes them to grow more lushly. It keeps them from growing stems and seedss, but one or two mowings causes the native grasses to actually shoot out more rhizomes and produce more leaves, which produces more photosynthesis. That makes more root-reserve carbohydrates, which are stored for fast growth next year. This double summer mowing suppresses the goldenrods and promotes the grasses. I highly recommend a year of this routine. You are likley to have a much denser stand of desirable grasses. The few forbs you have will still persist, and in a year or two they will start a seed rain that will slowly grow into new forb plants.

I would also highly recommend that you burn the entire plot next March or April, weather and legalities permitting. Nothing promotes prairie grasses and forbs like a good spring burn.

Thanks for your thorough reply, John.

I had already mowed once, a couple weeks ago, to about 8".
I basically smashed through the field of last year's high growth with my Ford 8N tractor and 60" finishing mower (raised high.) I don't own a flail mower or bushhog. This unfortunately left a lot of windrows (old goldenrod stalks etc.)

Then I burned. Areas of relatively dense grass (maybe 20% of the area) went up like a torch. Since burning, the grasses in those areas have grown vigorously (to about 8-12"). There's a lot more of it than I'd thought.

In the other areas, maybe 1/2 acre, I moved a second time with a push mower, bagging the clippings. Tiring work, but I got some GREAT compost material. We also raked up into mounds some of the remaining chaff from last year's goldenrods etc. and burned again.

And I did spray with Plateau, using 1 EcoPak (4 oz. rate) in 15 gals. of water, plus Activator 90 adjuvant, over about 1/2 acre where the burn was spotty
(mostly avoiding the good areas of denser grass). A day later, I spot treated
Field Bindweed and Thistle with Crossbow.

Finally, I went over some of the areas with a flame weeder, primarily to burn remaining chaff & expose more soil surface.

In another week or two we will interseed (using a "Plateau Tolerant" grass & forb mix from Errnst seed). The Maryland DNR is bringing us a Truax seed drill; a local farmer will plant for us. Then we'll watch & wait.

I'm pretty confident we'll get a good stand now, even if I've made some mistakes (with the Plateau or whatever). Occasional mowing in weedy areas (if necessary) sounds like a good idea. And if the new seeds don't emerge well this summer, we can always interseed again after the first frost.

This has been a lot of work, but now that I see all that prairie grass emerging
from the burn (even if it's only in the one section) I feel gratified.
This stuff is SO beautiful when it's reached full height in the field!

Don't be surprised to find a lot of seeds that don't germinate this year. Many of them have to go through a winter in the soil, so they'll pop next year.

If you can, check the Truax seeder to see if it has the standard 1-inch depth bands. You will see a shiney plate the cuts open the soil. Ideally, this should be the quarter-inch plate, but very few Truax owners use this. Try to get the person operating the machine to plant as shallowly as possible. Far too often, standard Truaxes are used to plant the seeds at one inch to half-inch depths. For farm people familiar with corn and soybeans, that good. For light and small praiire seeds, it's bad. Shallow is good. I've seen a number of Truaz one-inch depth band plantings where the prairie seeds were never seen again. They got buried just too deep.