When to Plant Bearded Iris Rhizomes
Plant your bearded Iris rhizomes in the late summer. For best results, newly planted iris should have enough time to establish strong roots before the growing season ends. We recommend planting iris at least six weeks before your area’s first hard frost.
In regions with hot summers and mild winters, planting in September or October is often ideal.
Where to Plant Bearded Iris Rhizomes
Plant your bearded Iris rhizomes in a sunny spot where the soil is well-draining and has a pH level of a little less than 7. If necessary, do a soil test and amend the soil accordingly.
How to Plant Bearded Iris Rhizomes
Allow for plenty of space between rhizomes so they don’t get too crowded. Prepare garden bed by loosening soil to a depth of 12 to 15 inches. Mix in a two to four inch layer of compost to improve drainage, if needed. Otherwise, mix a low-nitrogen fertilizer into the soil, such as a 6-10-10 mix. Dig a shallow hole that is large enough to accommodate the rhizome or clump of rhizomes. The hole should be about 10 inches in diameter and about four inches deep. Form a mound of soil in the center of the hole for the planting base. The rhizome should be placed on this mound—high enough so the top of the rhizome is slightly above soil level. Spread the roots down the sides of the mound. Fill the hole with soil, firm it gently and then water well. Each grouping of irises should be spaced about one to two feet apart.
Not all iris will bloom their first year. Sometimes they require more time to become established.
How to Care for Bearded Iris
When your bearded irises are done blooming for the season, cut back the green foliage to about four to six inches high so the plant won’t waste energy trying to maintain the leaves throughout the winter. Divide your rhizomes every three to four years. Keep in mind that bearded irises are not always guaranteed to bloom and will highly depend on soil, climate, and location. Some bearded iris re-bloom again in the summer, fall, or winter. Additional water and fertilizer applied during the summer months encourages them to bloom again. While they can vary from one year to the next, the flowers are always exquisite.
