Irises are one of the easiest flowering perennials to grow in your garden. Once your irises are established, you will be rewarded with gorgeous flowers year after year even if you don’t do anything- perfect for the lazy gardener. You don’t even need to water your irises and it is typically pest-free and disease-free with the exception of the Bearded Iris.
Just make sure your Irises are in a sunny location and they will automatically flower beautifully. The only thing you have to do is to cut back irises in the Fall to prepare it for the following year. Here is a beginner’s guide on how to care for your Irises.
How to Grow Irises Video
Below is a video on how to grow Irises.
Irises Planting Basics
| Name | Irises |
| Botanical Name | Iris |
| Flower Color | Many Colors- Purple, Pink, Yellow, Blue, White, Orange |
| Height | 24-36 inches |
| Sun | Full Sun |
| Soil | Moist, Well-Drained |
| Bloom Time | Early summer |
| Zones | 3-8 |
| Plant Depth | Japanese irises: 2 inches deep. Siberian irises: 1-inch deep. Bearded irises: Rhizomes are planted just below the surface of the ground |
| Plant Spacing | 12 to 24 inches apart |
| Toxic to Pets | Toxic to Cats and Dogs |
Irises: Varieties
Popular Irises varieties are:
Siberian iris or Iris sibirica
Siberian irises are one of the easiest iris varieties to grow. It is drought resistant and can even tolerate light shade conditions.
Bearded Iris or Iris x germanica
Bearded irises are the most sought-after iris varieties. Known for its stunning flowers.
Japanese Iris or Iris ensata
Japanese irises are moisture-loving irises. It required abundant moisture and grows best next to ponds and streams.
Irises: Size
Irises grow 8-36 inches tall. Dwarf bearded iris varieties can be as small as 8 inches while tall irises can grow to 36 inches tall.
Planting Your Irises
Where to Plant Irises
Irises are best planted in sunny locations receiving at least 6-8 hours of sunlight per day. They prefer moist, well-drained soil.
| Sun | Full Sun |
| Soil | Moist, Well-Drained |
How to Plant Irises
Dig a hole. For Japanese irises, dig a hole around 2 inches deep. For Siberian irises dig a hole around 1 inch deep and for Bearded irises dig a hole just deep enough to cover the top of the rhizomes. Center the Iris rhizome in the hole, spread out the roots, and cover with soil. Water thoroughly. Keep up with the watering until roots are established.
Use a bulb planter tool to make planting your bulbs easier.
When is the Best Time to Plant Irises?
Bearded irises are best planted in July, August or September while Japanese irises and Siberian irises are best planted in the Fall. Make sure you plant your irises at least 4-6 weeks before the first frost to give them sufficient time to grow new roots for winter.
Dividing Irises
How Often do you need to Divide Irises?
Bearded irises will suffer from overcrowding and will need to be divided every 3-4 years and Japanese irises need to be divided every 3 years. Siberian irises can grow in the same location without the need to divide it however, it will benefit from division since eventually, it will start to get overcrowded.
Check out: How to Divide Irises (video)
How to Divide Irises
Water the iris you will be dividing (or divide after rain). With a shovel, divide irises by digging up the entire Iris exposing the roots and rhizomes. Use scissors and a shovel to cut up the iris clump into several divisions. Plant each division in a sunny location with well-drained soil. Water thoroughly. Keep up with the watering until the roots are established.
Propagating Your Irises
How to Propagate Irises
The best way to propagate irises is by division. Water the iris you will be dividing (or divide after rain). With a shovel, divide irises by digging up the entire Iris exposing the roots and rhizomes. Use scissors and a shovel to cut up the iris clump into several divisions. Plant each division in a sunny location with well-drained soil. Water thoroughly. Keep up with the watering until the roots are established.
Care for Your Irises
Do You Need to Water Your Irises every day?
Irises are drought resistant. Once your irises are established, you don’t need to water them, natural rainfall should be sufficient. However, if you are experiencing drought or a dry spell, do water your irises. If you have newly planted irises, you should keep the soil moist to ensure root growth.
Do you need to Deadhead Irises after they Bloom?
Irises don’t need deadheading after they bloom. The only time you’d want to deadhead irises is if you have a rebloomer. Although, know that there is no guarantee that irises that are sold as rebloomers will rebloom after deadheading.
What to Do with Your Irises After They Bloom?
You don’t need to do anything to your Irises after bloom time. Leave it alone so that the leaves can bring in energy to feed the rhizomes for next year. Wait until after 3-5 frosts when the leaves completely die down before cutting back your irises.
How Often Should You Fertilize Your Irises?
Irises don’t need a lot of fertilizers. Fertilize your irises once in the Spring. For Bearded irises you can add a second application one month after bloom and Japanese irises will benefit from a second fertilizer application before bloom time.
What Fertilizer Should You Use on Your Irises?
Use a balanced fertilizer on your irises.
Troubleshooting Your Irises
Are Irises Deer Resistant?
Irises are deer-resistant plants. I’ve had irises in my garden for 2 decades now and I’ve never had any problems with deer. I also find that squirrels and rabbits will not bother your irises. Plant irises freely in your garden!
What are the common problems of your Irises?
Irises are typically pests and diseases free with the exception of Bearded irises. Bearded irises are commonly afflicted by Iris borers which is a pest that tunnels in the rhizomes. If you see brown leaf tips and dying leaves, it can be a sign of iris borers. Remove the affected leaves and dig out the rhizomes to see if there are tunnels and caterpillars. If you see these, get rid of the infected rhizomes.
Preparing Your Irises for Winter
How Should You Prepare Your Irises for Winter?
Cut back irises in the Fall by removing the stems and leaves. Cut your irises down so that only around 2 inches of foliage are left. Wait until after 3-4 frosts when the iris leaves have completely died off before cutting back irises. It’s important that you leave the leaves intact for a few weeks after the bloom dies so it can deliver much-needed energy to the rhizomes for next year.
Toxic to Cats and Dogs
Are Irises Toxic to Dogs?
Irises are toxic to dogs. According to the ASPCA, Irises contain Pentacylic terpenoids (zeorin, missourin and missouriensin) which are toxic to dogs. It can cause vomiting and diarrhea. Iris rhizomes contain the highest level of Pentacylic terpenoids.
Are Irises Toxic to Cats?
Irises are toxic to cats. According to the ASPCA, Irises contain Pentacylic terpenoids (zeorin, missourin and missouriensin) which are toxic to cats. It can cause vomiting and diarrhea. Iris rhizomes contain the highest level of Pentacylic terpenoids.
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Beginner’s Guide: How to Divide Irises (video)