Over the past few years, I have introduced you to the wonderful world of Irises. We have explored how to grow and propagate them, and how to use them in your garden. This year, I thought I might answer some of the questions I am most frequently asked.
1. What is an iris?
An iris is a hardy perennial with long sword-like leaves and showy flowers borne on long bloom stalks. The flower consists of six petals. Three petals called “standards” stand straight up and three petals called “falls” hang down. A beard is centered on each fall.
2. Do irises grow in Oklahoma?
YES! Irises are extremely easy to grow in our hot, dry and windy state. They require little maintenance.
3. When do irises bloom?
Irises send up bloom stalks in the spring and early summer. The Standard Dwarf varieties are the earliest to bloom with the Tall Bearded following a little later. Rebloomers bloom in the spring and then again in the fall. On occasion, I have found irises blooming at Thanksgiving time.
4. What kind of growing conditions do irises need?
Select a spot in your landscape which is well drained and will receive at least six hours of sunlight each day. Plant the rhizomes 12 inches apart to allow for increased growth. Provide your plants with water but do so in moderation.
5. When should irises be fertilized?
Select a fertilizer with a lower nitrogen (6-10-10) content. Phosphate is important for the bloom. I use bone meal whenever I transplant the rhizomes, about 8 weeks before bloom time, and again in the fall.
6. How do irises reproduce?
Irises grow from rhizomes and seeds. The fruit of the flower is a large swollen pod full of seeds. Be aware that seeds are the result of pollination, and your new irises may not look the same as the original plant. If you like surprises that is fine. Most iris growers prefer dividing the rhizomes to keep the iris true.
7. Should irises be mulched?
While some people do mulch around their irises and have no problems, most iris growers do not recommend this. Mulch creates moist conditions which can lead to rotting and the death of your irises. If you need to mulch other plants in your garden be sure to keep the mulch pulled back away from your iris rhizomes.
8. When should irises be planted?
Plant your rhizomes in early fall before freezing temperatures. This allows time for the rhizomes to get established before winter.
9. Where do I get irises?
Contact your local Iris Society. They sell rhizomes known to grow in your area, and you will have a broader selection of varieties from which to choose. In Enid, the North Central Iris Society will host its annual rhizome sale on Sept. 24 at the OSU Extension Center, 316 E. Oxford. Experienced iris growers as well as a few Master Gardeners will be on hand to answer your questions and offer suggestions for your landscape needs.
Redding is a member of Garfield County Master Gardeners.