How to Care for Irises

Choose a site with full sun, or that receives direct sunlight at least eight hours a day.

Plant iris rhizomes 2 inches deep in sandy soil; in medium-textured soil, situate rhizomes just below the surface of the soil. In clay soil, plant iris rhizomes so their tops are even with the surface of the soil.

Water iris in spring before they bloom to keep the soil moist but not sopping wet.

Hand-pull weeds and other undesirable vegetation growing near the iris. Carefully loosen the soil around their roots with a garden claw. Remove faded flowers shortly after they finish blooming.

Fertilize immediately after the plants finish blooming. Scatter approximately 1/2 cup of 5-10-5 fertilizer for every six iris plants. Healthy iris with rich, green foliage may not need supplemental fertilizer every year.

Cut the leaves down to about 6 to 8 inches from the ground in early fall. Cut the flower stem off near ground level after the first hard frost.

Mulch iris the first winter after planting to protect the newly planted roots from fluctuating winter temperatures. Use straw or hay and put down a 3- to 4-inch layer after the ground freezes in late autumn. In cold northern areas, iris will most probably require a protective winter mulch every year to protect the shallowly planted rhizomes from damage.