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Care of Iris Bulbs

By S.F. Heron ; Updated September 21, 2017

Iris bulbs contain everything the plant needs to create stunning flowers once a year. Irises come in many varieties, colors, shapes and sizes. All irises require the same type of care. An iris bulb looks like an elongated potato. Bulbs serve as a food-storage reservoir for the plant. Keeping the bulbs healthy before and after planted will encourage your iris to bloom with beautiful flowers and foliage.

Purchase iris bulbs that feel firm to the touch. Newly-bought or stored bulbs shouldn't feel squishy or dry. Don't purchase or plant broken bulbs. The safest place for iris bulbs lies underground, so try to avoid storage.

Choose the planting location carefully. Irises thrive in partial sun and in areas with good drainage.

Prepare the soil of the garden before planting the iris bulbs. Turn over the top 12 inches of soil, mixing in compost or organic soil conditioner. Irises like soil that's rich in organic material. Add an all-purpose fertilizer with slow-release properties to the soil.

Dig holes at a depth relative to the size of the bulb. Since each iris bulb varies greatly in shape, hole depth should fit the bulb completely, allowing for about an inch of soil above the bulb. Make the hole big enough to place the bulb without bending or breaking the tuber.

Plant one bulb per hole to prevent overcrowding. Space individual plants at least 10 inches apart to allow for plenty of growing room.

Water thoroughly without drowning the bulb. Irises don't need heavy amounts of water throughout the year, but the soil should be kept moist during bloom times.

Clip down stalks to 2 to 3 inches form the ground during the late fall. Apply a layer of mulch or straw to the garden surface above the iris bulbs for protection during cold winter months.


Things You Will Need

  • Trowel
  • Pruning clippers
  • Compost or organic soil conditioner
  • Fertilizer


  • Transplant and separate iris bulbs after the plant finishes blooming for the season. Dig up the bulbs and gently separate the bulb sections (they look like a pile of connected potatoes). Wiggle each bulb section loose, preferably with each new bulb containing some greenery. Plant the bulbs as soon as possible to prevent damage to the tender bulb. If you can't plant the bulb immediately, store in a cool, dry place until planting (no more than 3 days).