Classic bearded iris, featuring purple and yellow petals, survives for years in one location and can often be found around abandoned homesteads or along ditches in rural areas. Hybridization has produced an array of colors, making bearded iris a choice among gardeners who seek bright spring color in the perennial bed. These hardy plants thrive in a sunny location with well-drained soil and require relatively little care, other than occasional watering and separating of the rhizomes every few years.
Select a new area for the iris plants that receives at least 6 to 8 hours of direct sunlight per day. Prepare the planting area before lifting and dividing the original plants. Dig to a depth of 8 to 10 inches and amend the soil with 3 to 4 inches of well-rotted manure or compost. Add bulb fertilizer following the recommended application rate on the container.
Cut foliage on bearded iris back to 3 to 4 inches from the soil level 4 to 6 weeks after blooming. Remove any damaged or discolored leaves. This prevents moisture loss when transplanting.
Slide the edge of a spade or garden fork under the clump, taking care not to damage rhizomes. Rhizomes of over-crowded iris may be visible on the surface of the soil or even on top of other rhizomes with thick white roots extending into the soil.
Lift the clump free and shake it to remove excess soil. Gently pull individual rhizomes apart. Each section should contain a blade of foliage and have small white roots on the bottom of the rhizome.
Plant rhizomes in the prepared bed with the top of the rhizome resting just below the surface of the soil. Spread roots out and fill in with soil. Space 6 to 8 inches apart to allow room for roots to grow.
Water thoroughly and keep moist to encourage good root formation. Cover with 3 to 4 inches of mulch in late fall to protect from harsh winter weather. Remove mulch in spring when new growth appears.