How do I save my iris bulbs for next year?
Written by
Tina Carter
Reviewed by
Prof. Martin Thorne, Ph.D.Immediately start the process of saving iris bulbs once you have dug them up. You should wait until the foliage yellows as naturally as possible, and then, with gentle care, you can lift the rhizomes using a garden fork. I once lost a rare Japanese iris, rushing it because I became impatient. I do recommend waiting until all of the energy has transferred to the bulb. Afterward, the bulbs should be dried in a shaded and ventilated area for about 7 days.
Weeks 1-2: Moisture Check
- Inspect sawdust for dampness
- Replace material if clumping occurs
- Wipe condensation from storage containers
Weeks 3-4: Pest Patrol
- Look for iris borer larvae (white with brown heads)
- Remove infected bulbs immediately
- Apply diatomaceous earth to storage area
When it's time to put your iris rhizomes in storage, you want to use mesh bags. So, that you do not have them sealed in a container. I make use of onion sacks that I hang from the rafters in the basement. This is similar to nature in that they need airflow. One client's attempt to store in a plastic tub resulted in an 80% loss due to rot. Airflow is essential.
Regional humidity impacts storage adjustments. In Florida, I use silica gel packs to address the humid air. Arizona gardeners use barely damp newspapers to wrap the bulbs. My Colorado clients keep root cellar storage at 40°F, but consistent temperatures beat fancy equipment.
Restore shriveled bulbs by soaking in water for two hours before planting. To test for viability, try to snap one small root; good bulbs will bend rather than snap. Last spring, I restored a total of 15 "dead" irises that bloomed and were beautiful. I now soak bulbs in water for two hours to see if I can get some blooms. Don't discard bulbs unless you check them out!
Read the full article: How to Store Bulbs: Expert Guide for Healthy Blooms
