How to Plant Irises

Irises are one of my favorite flowers. They’re spectacular! Tall and colorful, with delicate blooms that last for about three weeks and come back next year- what more can you ask of a flower?

To top it all off, irises are very easy to grow. Irises grow from rhizomes; they’re a lot like bulbs, but they’re planted differently. Here’s how to plant them:

First, select an appropriate spot and time. The area must get lots of sun and can’t be low lying. Irises that don’t get enough sun will sprout green leaves, but they will not bloom. And irises that are planted in standing water will rot and die. So picking the right spot is very important.

The best time to plant irises is in mid-summer for two reasons. First, rhizomes are planted in mid to late summer to give them time to settle into the soil and develop roots before winter. Second, people all over town are digging up their irises and dividing them, so you can probably get some rhizomes for free. If a friendly neighbor has irises, let her know that you’d be interested in starting some in your yard. Volunteer to help her divide them this summer in exchange for a few rhizomes. That way you’ll get to work with someone who knows how to grow them and get a few starts for your yard. Or you can just buy rhizomes, which is less fun.

Next, dig the soil to loosen it up, just like you would with any other flowers. If you dig about 6-8 inches deep, that’s enough for irises.

To plant: Dig a shallow trench for each rhizome. Place the rhizome in the trench with its roots or eyes (starts of roots) in the dirt. Do not bury the entire rhizome. Just cover the roots and eyes with dirt, leaving the top of the rhizome above the dirt. If they are planted properly, you will see about 25% of the rhizome, a rounded surface, just above the dirt. Plant the rhizomes at least 6 inches apart. Irises spread fast, which is a good thing, so give them plenty of space to grow.

Give them a little water to get them going. That’s it! Your irises are good to go. You’ll probably notice them putting out a few leaves in fall. That’s a good sign; just leave them alone. The next spring, you may or may not have flowers. Sometimes new irises don’t bloom the first year. Be patient. By the second year, they will have spread and will bloom well.

That’s the right way to plant irises, but I have learned that they are not really picky about planting. One fall, I gave my cousin, the one with the green thumb, several rhizomes in a small paper bag. She set the bag in her yard, under a bay window in a sunny space where she intended to plan them, and forgot all about them. The next spring, she showed me her beautiful paper bag irises, never planted but blooming profusely, bag still in evidence around the rhizomes. So, while I don’t recommend my cousin’s paper bag planting method, you should keep it in mind if you are afraid of planting them wrong. Pick the right spot and all will be well.