Find out when to cut back irises to keep these perennials healthy and looking their best.
But when to cut back irises?
After their colorful flowers wither, or should you wait until fall, or even until after winter?
Credit:Robert Cardillo
This guide explains how and when to cut back irises to encourage healthier plants and more flowers.
Dean Schoeppner
After Blooming
Dont cut back the foliage but do cut off the flower stalk.
If the foliage is green and healthy, wait until fall to cut it back.
Credit:Dean Schoeppner
Heres why: the foliage is an energy factory, transforming sunlight and carbon dioxide into glucose and oxygen.
The glucose is a key component in developing bigger iris roots, also known as rhizomes.
Large rhizomes produce large flowers and a more robust plant.
Credit:Kritsada Panichgul
Cut back yellow, streaked, or brown leaves as soon as you notice them.
Removing the leaves can help limit thespread of plant diseasesor pests.
Continue to check the iris planting for signs of pests or disease weekly.
The helps reduce stress on the divided sections as they focus on growing more roots after being replanted.
The best time to divide irises is 4 to 6 weeks after they bloom.
This will give the newly planted divisions enough time to become well rooted before winter.
A healthy stand of iris will multiply rapidly.
Plan to divide your irises every 3 to 5 years to prevent overcrowding and reduced flowering.
In fall, cut the foliage back to 6 to 8 inches above the ground.
confirm toclean your prunerswith a disinfectant such as rubbing alcohol between plants to avoid spreading existing issues.
Bury the foliage in a deep trench away from your irises or toss in the trash.
Fertilize repeat bloomers with a balanced fertilizer in spring and again after the first flowers of the season fade.
In areas with freezing winters, irises benefit from a 2- to 3-inch-thicklayer of mulchthe first season after planting.
Cover rhizomes with bark mulch, straw, or evergreen boughs after the ground freezes.
Remove the covering in early spring to make way for new growth.
