How to get irises to bloom?

There can be many reasons why the iris are not blooming. They need to be in full sun and well drained soil to do their best. Overcrowding can cause them not to bloom. Iris should be divided every several years. I would recommend digging them up if they are crowded in and divide them and space them apart with about 6 rhizomes in each grouping. When planting make sure the rhizomes are just barely beneath the soil level. Planting too deep is also a cause of non blooming. The last thing is they do not like mulch up against them. I hope this helps.

Depending on where you live now is a good time to divide the iris and replant. I live in a northern climate so I do mine at the end of August/early September--Zone 3. If you are a bit warmer you still have some time to do this. You can add some bulb fertilizer to the dirt as this helps--even though iris do not have bulbs--they have rhizomes. When you divide the iris and replant they will not flower the first year after they have been divided. Their energy goes into reestablishing the rhizomes. You want to leave them all summer and then cut back in the fall for the following spring.

Yes, when irises get too crowded, they may have fewer blooms. If you dig them up in the fall and divide them, you can replant less crowded beds. That should get you some blooms!