Choose a planting site in full sun and amend the soil with plenty of compost or other organic matter. If soil is acidic, also add lime.
Get rhizomes into the ground immediately; they can't tolerate drying out. Plant 1 inch deep in heavy soil, 2 inches deep in sandy soil. Space rhizomes at least 2 feet apart. Keep them well watered from planting through bloom period.
You'll get more blooms if you feed spuria consistently. One strategy: apply a balanced, controlled-release fertilizer in early spring and again in early autumn.