Irises are a very care free plant, they do like the sun, and not so much water. In fact too much water can cause problems for them. They can get rot on the Rhizome from being immersed for too long. Irises can also get what is called leaf spot which can stunt their growth. Spring and Summer is when they bloom, but some of the Irises will actually bloom in both the Spring and the Summer, these are called rebloomers. Another consideration when planting irises is the pesky garden slug. Slugs can cause a very large problem in a garden. Slugs like to eat the Rhizome and the leaf part of the iris, causing possible stunting, or early death of the plant.