How to Grow Bearded Irises


Bearded irises are herbaceous flowering perennials that grow to about 2 feet in height and produce large, ornamental flowers. They bloom during spring and can be red, yellow, orange, green, blue, pink, white or purple in color. Bearded irises are not native to North America, but they can easily be grown in most temperate climates if proper care is given throughout the growing season.

Step 1

Plant bearded irises between the months of July and September in a location that receives full sunlight throughout the day. Fertilize the soil before planting using a low nitrogen 5-10-10 NPK fertilizer; follow the manufacturer's instructions for proper dosage and application.

Step 2

Dig a hole just large enough to hold the rhizome; form a small mound of soil in the base of the hole. The mound should be high enough to allow the top of the rhizome to sit just above soil level. Place the rhizome into the hole and spread out the roots so they run down the sides of the dirt mound.

Step 3

Refill the hole and water thoroughly to compact the soil around the roots. Plant other bearded iris rhizomes at least 10 inches apart to allow plenty of room for growth. Spread a 3-inch layer of mulch over the soil surrounding the rhizomes immediately after planting to add protection throughout winter.

Step 4

Water bearded iris twice per week during spring, summer and fall to keep the soil consistently moist but not soggy. Reduce frequency of watering to once every two weeks in winter, and only when there has not been at least 2 inches of rainfall.

Step 5

Feed bearded iris twice per year, once just before new spring growth begins and again in late spring just after flowering ends. Use a 5-10-10 NPK fertilizer to avoid burning the rhizome. Apply following the directions provided on the packaging.

Tips and Warnings

  • Do not splash water onto the foliage when watering, since damp bearded iris leaves are extremely susceptible to fungal diseases.

Things You'll Need

  • Fertilizer
  • Mulch


  • Cornell University Flower Growing Guides: Iris, Bearded
  • North Dakota State University Department of Agriculture: Iris
  • Bearded Iris for the Home Landscape
Keywords: bearded irises, bearded iris, bearded iris plants

About this Author

Willow Sidhe is a freelance writer living in the beautiful Hot Springs, AR. She is a certified aromatherapist with a background in herbalism. She has extensive experience gardening, with a specialty in indoor plants and herbs. Sidhe's work has been published on numerous Web sites, including