Your containers needn't be fancy. All you need to create a miniature prairie in an urban setting is some imagination, potting soil, ornamental grasses and a used rubber tire. Line the tire with landscape fabric or recycled widow screen so the soil won't wash out. Then fill the void in the tire with potting soil or compost. Before you add plants, make sure all those growing together have the same requirements for sunshine and water.
Most sedges occur naturally in bogs, damp woodlands or by water and prefer a moist soil.
Sedges appreciate midday shade in the hottest climates. Bulrush is native to wetlands. Red-hot poker is native to southern and tropical Africa. Mint is a perennial and requires plenty of water and full sun. Once the plants are in place, fill in with soil, stopping a few inches below the rim to permit easier watering.