Sumo Gardener

Siberian Iris | Complete Growing and Care Guide

Siberian irises, or Iris sibirica, is a stunning, herbaceous perennial just perfect for spring gardens. This intricate and colourful flower is incredibly easy to care for, even easier to propagate and will offer you lush and lasting blooms throughout the spring and into the summer.

Here is everything you need to know to plant, grow and care for Siberian irises.


Siberian Iris Complete Growing and Care Guide

Siberian Irises Growing Guide

Siberian irises, or Iris siberica, is a stunning, herbaceous perennial just perfect for spring gardens.

Siberian irises are fairly easy to grow, and with the proper maintenance, they’ll flower big and bright year after year. Although native to North Asia, this perennial is a popular choice for many temperate gardens. 

Although it has a fairly neat growing habit, Siberian irises love to spread. So, you’ll need to make sure you find the right spot for them, or you may find yourself having to pull out unwanted plants from areas you don’t want. 

Still, Siberian irises are an attractive choice for many gardeners. They also attract a range of nectar feeders like bees and butterflies. Plus, they’re resistant to some pesky garden visitors like rabbits. 

The most popular Siberian iris varieties to grow at home include: 

  • Butter & Sugar / Snow Queen. This variety offers stunning white and yellow blooms. 
  • Sultan’s Ruby. This intricate cultivar produces stunning magenta blooms. 
  • Ceaser’s Brother. Another stunning purple bloomer. 
  • Wine on Wine. A pure white bloom producing cultivar.

How to Grow Siberian Iris

how to grow siberian iris

Ideal Conditions for Planting Siberian Iris

According to gardeners, there is a range of ideal planting times for Siberian irises. In colder areas, it’s recommended to plant during early spring. In particularly warm areas, it’s recommended to wait until the summer has cooled a little to begin planting. 

Siberian Iris can grow quite happily in pots or in the ground; however, you will want to use a suitable growing medium and pick a spot with enough direct light. 

Do Siberian iris-like Sun or Shade? 

This will depend largely on your frequency of watering and how many blooms you’ll want. In general, the more sun your iris receives, the more it will bloom. However, you will need to ensure you keep up with regular watering to avoid the roots drying out. 

If you’re worried you may forget to water from time to time, a semi-shaded spot will be preferable. 

What kind of soil is best for Siberian Iris? 

Siberian irises do best in rich, fertile soil. However, they have been known to reproduce even in poorer soil. The most important thing is that you ensure good drainage. Irises tend to easily fall victim to root rot. 

A general soil PH level between 6.5 and 7 is also recommended. 

How to Propagate Siberian Iris

siberian iris varieties

The most successful method to reproduce Siberian iris is through rhizome division. This cultivar grows a network of rhizomes beneath the surface of the soil, this makes it a useful plant for soil erosion, but it also means it can easily be divided to create multiple smaller plants. 

Yearly division of existing plants will not only give you new plants but will also stimulate the old plant to grow more rigorously in the year to come. 

Most gardeners will recommend dividing your iris right after they bloom as the roots will still be undergoing a growth phase. Once divided, simply plant the rhizomes into the ground, 1 to 2 inches deep and 1 to 2 inches apart. 

Do Siberian Irises Bloom more than Once? 

The regular division is the best way to guarantee that your iris will continue to bloom year after year. Plus, you can enhance your garden with lots of new little plants.

Caring for Siberian Iris

caring for siberian iris

Your Siberian irises will require some regular care and maintenance, especially because they do tend to spread. Most importantly, you will want to keep the soil around your irises consistently moist during the growing season.

However, take care to only water lightly and avoid drenching the soil completely. Regular fertilizing is also beneficial; a nitrogen-rich fertilizer will do best for irises. 

Mulching your soil regularly will also help to keep the soil cool and avoid drying out during the heat of the summer. More so, it helps to deter any pesky weeds from taking over your beds. 

Should I deadhead Siberian Iris?

Many gardeners will recommend deadheading your iris after blooming. This will help to promote a fuller bloom in the following year. However, your iris will then no longer produce seed pods during the winter. 

So, if seeds are what you are looking for, avoid deadheading altogether.

Pests, Diseases & Problems

This specific cultivar of the iris species is particularly disease resistant. As such, you will likely not have any issues with it. However, it is incredibly susceptible to the Iris Borer, which can quickly kill of your plants. 

Siberian Iris is incredibly susceptible to the Iris Borer

It is recommended to spray your Siberian iris with a systemic insecticide twice a year should you fear an infestation. 

Are Siberian Irises toxic to dogs? 

Unfortunately, some species of iris contain certain compounds which are mildly toxic for pets. Should they ingest any parts of the iris plant, they may salivate, drool, have diarrhea or vomit. 

In some cases, irises can cause minor skin irritations in humans. 

Why Did My Siberian Iris not Bloom? 

A lack of flowering can be due to a variety of issues. These include: 

  • Weather
  • Soil Fertility
  • Overcrowding
  • Unhealthy Rhizomes
  • Insect or Disease Attack
  • Lack of Planting Depth
  • Site Conditions

You will need to consider all of these conditions to determine what may be causing the issue.

Final Growing Tips for Siberian Iris

  • Although they look quite delicate, Siberian Irises are pretty rugged. So, don’t worry if you forget about them from time to time. 
  • Avoid adding manure to your irises unless they are more than a year old. 
  • While you do want a good amount of sun per day,  a little bit of partial shade will help to retain Bloom’s brightness. 
  • Siberian irises are not drought tolerant so try to remember to water them as much as possible.

Looking for some other fantastic flowering plants to add to the collection? Take a look at our guide to growing pastel flowers.

Yes, spring gardens always do best when they’re planned well in advance. So, if you've wanted a bloom filled back garden in the next year, start planning your Siberian irises today. 

About the Author Ann Katelyn

I'm Ann Katelyn, Creator and Chief Author of Sumo Gardener. Since I was a child I've always been fascinated with plants and gardens, and as an adult this has developed into my most loved hobby. I have dedicated most of my life to gardening and started Sumo Gardener as a way to express my knowledge about gardening with the hope of helping other people's gardens thrive.

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