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Why Are My Irises Not Blooming? Oops!

Why Are My Irises Not Blooming? Oops!

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Are your Irises are not blooming this year yet? It can be disappointing when you get little to no blooms.

Irises are considered hardy perennial flowers that can grow as long as their basic needs are met.

Here are some of the issues I have seen in my irises.


Why Are My Irises Not Blooming?

Irises may not bloom for a few reasons including issues with shade, water, space, nutrition. The most common issue with irises blooming is how deep the bulb or rhizomes is planted. If the bulb is planted too deep the iris will sprout greenery but will not show any blooms. An iris can also bloom one year and not bloom the next. This can be due to the problems listed or the type of plant.


5 Reasons Why Irises Aren’t Blooming

There are five reasons an iris may not bloom.

  1. Not enough sunlight
  2. Over or underwatering
  3. Planted too deep
  4. Not enough space
  5. Poor soil nutrition

While these are the most common issues to occur with irises, another issue I have seen is in the plant itself.

An iris will often need a year to establish roots before you see any blooms. If you have recently planted your iris, give it another year to establish itself.

Depending on the variation of your iris you may also have a species that does not bloom every year.

The common bearded iris is dependable and will bloom between March to May. The Siberian Iris blooms later in the season.

I have found the iris to be a hardy plant that is often resistant to insects and fungus.

It is best to make sure all the common issues below are not affecting your irises before testing for fungi or insects.


Too Much Shade

An iris will grow in a shaded area, but it will produce little to no blooms.

Irises need 6 hours of direct sun each day to bloom. Full sun is especially important for reblooming species.

Make sure your iris is not covered by other plants or trees and that the entire plant is exposed to the sun.


Too Much or Not Enough Water

Irises need well-draining soil to create their blooms. The plant is drought resistant.

It is best to water well at the beginning of the season to ensure the roots of your new iris take.

If the bulb or rhizomes are mushy or soft you will not see any flowers even though the iris may still grow greenery.


Planted Too Deep

The iris rhizomes and bulbs need lots of air and sunlight to grow.

I have found that planting iris rhizomes so that they are poking out above the soil creates the best results.

If your iris is too deep you can see some growth, but your blooms will be limited.


Not Enough Space

Rhizomes multiply as the iris grows. Your iris bulbs should be about 12 to 24 inches apart.

They will commonly overcrowd themselves within two to four years of growth.

I usually dig up and split the rhizomes every few years to increase the space the iris has to grow. This will increase bloom production.

You may want to move your iris if the area your iris is growing in is dense with other fast-growing plants.

Your iris needs room to grow. Weeds and other plants can start to choke out the iris roots.


Poor Soil Nutrition

The final issue you may run into is poor soil nutrition. You can get a soil tester from any hardware store. Check the nitrogen and pH of your soil.

The PH should be 6.8 to get the best blooms. Make sure your soil is set up properly to feed your plants.

Fertilize irises in early summer if your soil needs extra nutrients. Your iris should not need constant fertilization unless your soil is low in nutrients.


Weather Conditions For Your Iris

There is a chance that a late freeze in your area caused your bulbs to freeze or become dormant.

I plant my iris bulbs or rhizomes in late July to September to give the bulb time to grow roots.

If the freeze happens before the bulb is established then the iris may go dormant for the year. Allow your iris time to establish itself before giving up on it.


Frequently Asked Questions About Why Are My Irises Not Blooming


What is The Best Fertilizer For Irises?

The best fertilizer for your irises is a low nitrogen fertilizer at a 5-10-10 split. Most common garden fertilizers will work. You can also use bone meal as a fertilizer on irises. I place the fertilizer around the bulb or rhizome, not on it. It is best to fertilize your plants a month before you expect them to start blooming.


How to Get Irises to Rebloom?

To help improve your iris blooms, start by pruning your irises to help them rebloom in the same year. Then, make sure your fertilizer offers the right nutrients. Lastly, watch out for weeds. For a better-looking garden, I mix and match iris species to increase the length of time the garden blooms. The Bearded iris blooms early in the year while the Siberian iris blooms later. Mixing these species will give your garden a mix of beautiful blooms throughout the year


How Long Do Irises Bloom?

An iris will bloom for about two weeks each year. Many iris variations will rebloom throughout the year. Some variations will only bloom every second year. Pick a mix of iris species to help your garden look full all year long.


Creating The Best Iris Blooms

The iris is a hardy plant. That doesn’t imply that an iris on its own will bloom.

The iris can grow tall and green in poor conditions. An iris will not bloom in poor conditions.

Keep your garden clean and free of weeds, make sure your iris gets plenty of sun, and don’t forget to split rhizomes at the end of the year.

Overcrowding is the most common issue for iris blooms. A beautiful bloom will come when the iris has room to grow.