your rhizomes no longer bloom? Multiply them!

Have you ever noticed that your irises produce leaves, scatter on the ground, but bloom less and less? This is a sign that they have become too old! To give your rhizomes a boost, you need to divide them to create vigorous new plants that will provide new flowers. Division is very simple to do, so find out how to proceed in order to have the pleasure of finding abundant iris flowers the following season.

Why your irises are no longer blooming

According to Odile Roussial, manager of a floral park in Loiret, iris rhizomes multiply naturally and can stay in the ground. 5 ans (6 years maximum) after planting. Then, their nutrient reserves are depleted and the rhizomes produce fewer and fewer flowers. It is the sign thatthey have to be divided.
iris leaves
Credit: Aleksey Gromov/iStock

What is important to remember is thatan iris rhizome blooms only once. After it blooms, it will produce other rhizomes that will bloom the next season, and so on. It is for this reason that old iris beds develop very few flowers, despite a large number of rhizomes. After each flowering, it is therefore necessary to cut the faded floral stems. If your irises are looking sad this year and you want to add some color to your garden, find a list of 25 flowers that bloom in summer.

Division can also be considered if the tufts become too tight, or quite simply if you want to multiply a variety. This operation is carried out after flowering, preferably in July-August, because irises fear excess humidity. Planting can be done until October if the climate is mild.

Divide an iris rhizome

  • Plant a toothed spade all around the iris tuft, being careful not to touch the roots.
  • Dig up the stump by levering to extract a clump of several rhizomes.
  • Shake the rhizomes to loosen the soil.
  • Using a sharp tool, select and release healthy rhizomes: firm and with many roots. Do not take a rhizome that has already flowered in the year, because it will not bloom again. Do not take either too small rhizomes which will be slower to grow.

irisCredits: Youtube/Easy Gardening

Trim the rhizomes

  • Cut a small part off the end of the rhizome to promote root healing.
  • Bevel cut sheets keeping only about 10 cm in height.
  • Take hold of all the roots with your whole hand and shorten any that stick out of your hand.
pruned iris rhizome
Credits: Lucile/Easy Gardening

Planting technique

  • Dig shallow holes 40cm apart.
  • Place the seedling with the roots in the hole and the top of the rhizome protruding slightly from the surface. The emerging part of the rhizome should appear to be lying on the ground.
  • Backfill and tamp the soil with your hands, then water.
iris rhizome
Credits: Youtube/Easy Gardening