How to Plant a Purple Iris

Naturalized purple iris in bloom. image by Leslie


Irises are a large family of flowering perennials grown from underground bulbs with dozens of species and varietals, many of which are variant shades of the color purple. Iris bulbs are planted in fall or early spring and produce blooms on tall, slim stalks in late spring and summer. Most iris varieties are hardy in USDA zones 5 through 9 and thrive in full sun.

Step 1

Prepare a planting bed for your iris in a location that receives full sun throughout the day and only an hour of two of shade at a maximum. In zones where iris are winter hardy, plant your bulbs in the fall at least six weeks before the ground freezes. In cooler climates plant your iris bulbs in the spring when the ground has warmed enough so that the soil can easily be dug and worked.

Step 2

Till the planting soil well to a depth of at least 8 in. and settle the churned soil with your hand or a tool to level it. Bury your iris bulbs 6 inches down in the soil at intervals of 4 to 6 inches apart. Water lightly after planting. To keep track of what you planted, use stakes or markers to note the planting spot and label the varietal.

Step 3

Watch the soil moisture around your iris bulbs throughout the seasons so that the soil surrounding them is never completely dry. In the spring begin maintenance watering to keep the soil evenly moist through the summer and early fall. Mulching with soil around the bulbs and growing plants will help to prevent water being lost to the atmosphere and will help nourish the soil. Consider using cocoa hulls, shredded bark, compost or leaf mold as your mulch material.

Step 4

Feed your iris bulbs and plants each year in early spring when green shoots being to emerge from the soil. Apply a granular or water-soluble dissolved crystal bulb fertilizer according to the package directions and always err on the side of underfeeding rather than overfeeding to prevent leggy growth and the build-up of mineral salts in the soil. Apply a second dose of bulb fertilizer in the summer after flowers being to fade to prepare the bulbs for dormancy and next year's bloom.

Step 5

Harvest fresh iris blooms for cut flower arrangements. Deadhead fading or spent flowers by cutting the stem off at its base. Allow the foliage to yellow and die back in the fall and winter, which will allow the nutrients in the foliage to help recharge the bulb for next season's bloom.

Things You'll Need

  • Iris bulbs
  • Water
  • Hand trowel, cultivating fork, shovel or rake
  • Organic mulch material
  • Bulb fertilizer


  • Martha Stewart plant profile on purple iris
  • Dave's Garden expert gardener exchange site
  • USDA Plants Database Profile
Keywords: purple iris, flowering bulb, plant

About this Author

A communications professional, D.C. Winston has more than 17 years of experience writing and editing content for online publications, corporate communications, business clients, industry journals and film/broadcast media. Winston studied political science at the University of California, San Diego.

Photo by: Leslie