Spuria Iris Culture
If you grow bearded irises you can grow Spurias. If a few guidelines are followed, Spurias will reward you with beautiful garden bloom and long lasting cut flowers.
Spurias prefer a neutral to slightly alkaline soil with good drainage. They prefer full sun but will tolerate partial shade in places that have extremely high temperatures in the summer. Most hybrids have a late summer-dormant period, and a drying off period during July through August is beneficial. In some dry areas you may need to water through July, but then hold back the water in August. In established clumps, water should be withheld until fall growth begins.
Spurias are very heavy feeders and will reward you if you incorporate plenty of barnyard manure and/or commercial fertilizer into your soil. If fertilized annually, clumps will persist and bloom for years. (10 to 15 year clumps are not unusual and eventually spread to as much as 5 to 6 feet across.
It is best to transplant in the fall and water well until the growth begins. Once established, spurias are drought resistant. Heavy irrigation in the spring increases growth and bloom. When spurias are dug to be transplanted, be sure to keep the roots and rhizomes moist. This is most important, as they will not tolerate drying out or being out of the ground.
Planting depth depends on the type of soil. If you have heavy soil, you will need to plant at least one inch deep. If sandy soil plant two or more inches deep.
Virus affects some spurias, although it is seldom very debilitating. It can cause stunting or striping of the plant and petals. The only serious disease is mustard seed fungus or crown rot. This also affects Louisiana, bearded iris, and daylilies. Soaking the rhizomes in a 5% sodium hypochlorite solution before planting is an effective control.