Seed would likely be the most economical way to do it. You'll need 1/3-1/2 a pound of it for 500sf. Rent a spreader if you don't have one. Prep the soil well, and follow normal grass seeding methods.

I did this on my lot and its about the same size. I planted bluestem, sideoats grama and blue grama using both plugs and seed. I am happier with both the sideoats and the blue gramas than I am with the bluestem which I am replacing in many spots. It has a tendency to flop unless planted in very dry poor soil. The sideoats is much nicer, well behaved and more decorative all through the season.

The plugs established quickly the first year and seeded. Year two had plenty of new plants. This worked well for me in a small space. I also mixed in some low growing natives that quickly naturalized.

Here is a photo shot at a local park showing native grass plantings. The upright grass in the foreground is Sideoats Grama. The one that is with it that is flopped over is Little Bluestem. Behind both of these is a swath of Love Grass that was stunning, I thought you might want to see this comparison.

Here is a photo from my lot showing Blue Grama catching the afternoon light. Its another very good choice. It and the Sideoats grama bloom a couple months earlier than the bluestem so you can get some nice seasonal interest by adding these.

Here is a small section showing results after three years shot in early fall. All grasses were sown from seed in late winter except for the Bluestem. I purchased 8 small 'The Blues' bluestem plants from Santa Rosa Gardens online and had tons of new plants the next year. This shows Little Bluestem (the pinkish one) Sideoats (the upright one to the upper left) and blue grama (the small tufty one with the white seed heads by the blue padded cactus) with mixed natives that quickly naturalized as have the grasses. The yellow plant in the front corner of the picture is bitterweed. I love this plant for naturalizing because it forms neat bouquets of yellow flowers that bloom from spring until early winter and it looks great with the grasses.

This post was edited by GreatPlains1 on Tue, Sep 10, 13 at 16:58