Siberian irises are among the easiest of all types of iris to raise and bloom in the temperate climatic zones. Their graceful stems, blooms, foliage, and neat habit of growth make them the most adaptable irises for the perennial border and for landscaping. Their handsome foliage is attractive all year, even when the first frost turns them a rusty red-brown.
In northern states, Siberians do best in full sun, or at minimum six hours of sunshine. In hot southern areas, protection from the mid-day sun is often a requirement. They enjoy lots of moisture in spring, and will do best if given a minimum of one inch per week during the balance of the growing season, so plant them with other perennials, such as daylilies which also need constant moisture to keep doing their best. They tolerate, but do not appreciate, summer drought.
Requirements vary depending on your garden soil, but most successful growers use a balanced fertilizer, such as 10-10-10, or a 14-14-14. Fertilize in early spring, and again after bloom season, to encourage growth for next year.