Why Do Bearded Irises Not Flower Every Year?


Bearded irises, also known as Iris x germanica, are known for their dependable colour and low care requirements. They may be grown in gardens year after year. The flowers bloom between March and May, depending on the cultivar, and come in practically every colour imaginable. Additionally, the flowers are enormous and magnificent. After being planted, some irises may not blossom at all, flower more slowly than normal, or cease blooming altogether; this is often the result of adverse growth circumstances. However, certain cultivars may not bloom as well in a particular location for reasons that are not fully understood; we refer to these plants as irregular bloomers.

Planting Irises

If you plant new irises or transfer rhizomes from clump divisions, the plants often won’t bloom the following year. This is because young irises need some time to get established before they can produce enough roots to support flowering. Irises are susceptible to not blooming if they are planted at a depth that is too great. However, the top of the rhizome should be at or slightly below the soil surface. The fibrous roots should be planted deeply. It is important to keep the mulch away from the rhizome crowns. Check the size of the rhizome before you plant it; if it is little, it may be a juvenile rhizome that has to develop for a year or two before it can achieve maturity and produce flowers. If the rhizome is large, it may be a mature rhizome that may produce flowers immediately after planting.

Plant Spacing

If you place your irises too tightly together, they may not bloom. When planting fresh iris rhizomes, leave a distance of between 12 and 24 inches between each one. Because the iris will produce more flowers if you point the end of the rhizome that bears the fan of leaves toward an empty space in the bed, you should position the rhizome so that it faces in this direction. The plants will have space to expand over the following two to three years as a result of this. Irises often cease flowering anywhere between two and four years after they have been planted because the plants get overrun with new growth. Dig up the clumps and separate them into individual pieces. You may either replant the divisions, give them away to friends, or give them to the iris organisation in your area to use.

Plant Location

To produce beautiful blooms, irises must get at least six hours of direct sunshine every day. If you have your irises in an area that receives a lot of shadow, there is a chance that they may not get sufficient light to create flower stalks, even if their leaves will continue to grow. If you plant irises in a location that is too near to another kind of plant that grows quickly, the irises may not bloom because of the competition for food and moisture. They need to be replanted in a location with more open space. Likewise, prevent weeds and debris from your iris bed.


Iris do not need a great deal of fertiliser. If you feed them a fertiliser that is heavy in nitrogen, this will actually prevent them from flowering. The number of blossoms will decrease as the number of leaves grows. Irisarian Bill Smoot, in an interview with the “Daily Press” in Hampton Roads, Virginia, suggests applying a fertiliser with a formula that is “no higher than” 10-10-10. This recommendation was made by Smoot. If you grow irises in a location that has been used as an iris bed for a significant amount of time without any soil amendments or fertilisation, you may want to get the soil tested to determine whether or not it is deficient in any nutrients and then amend the soil as recommended by the test results. Nutritional deficits may hinder blossoming.