Relations and functions | Functions and their graphs | Algebra II | Khan Academy
I'm sure I read that leaves should be left alone for six weeks to strengthen the iris and create more offsets. They can be cut back, lifted and moved after six weeks. So if you can pot up the annuals and wait the six weeks, then move enough irises to plant your annuals at that time. Thanks Good ideas. Think I will wait 8 weeks, then lift some Iris and move thus freeing up space for annuals.
You will want to dig and divide them every 3-4 years to remove the old rhizomes in the center of the clump that won't bloom again. This is usually done in August or September . Siberian iris can be fertilized in early Spring and after bloom with regular fertilizer (like 10-10-10). They like even moisture through the growing season. You don't have to remove the bloom stalks if you don't want to, or if you want them to reseed. After the leaves die back, cut them off a few inches above the ground. * Apply a thin layer of compost around the base of plants each spring, leaving the rhizome exposed.