I transplanted Iris' 4 years ago. Got blooms the first year and none since. Beautiful foliage and has spread.

Answer 1

Here are a few reasons why bearded irises may not bloom:
Inadequate sun
Bearded irises need at least 6 hrs of direct sun a day to bloom well.
Planted too deeply
Bearded iris rhizomes should be planted so the tops of the rhizomes are at or slightly below the soil surface. If planted too deeply, bearded irises will grow leaves but may not flower. Be careful, also, not to allow mulch to cover the rhizomes. Make sure any mulch is pushed away from the rhizomes.
Overcrowding
Overcrowded clumps often quit blooming until they are divided, OR irises closely planted with other plants may not bloom well (or at all) if they are struggling to compete for sunlight, water, and soil nutrients.
Nutrient deficiencies
Soil that has been growing irises for many years without amendments or fertilization is probably nutritionally depleted. Also, avoid high-nitrogen fertilizers. If bearded irises are fed high-nitrogen fertilizers, they may grow lush foliage with little or no bloom.
Inappropriate watering
Bearded irises might not bloom well if they experience periods of extended drought, though the plants themselves are quite drought-tolerant. Conversely, bearded irises that are overwatered are often susceptible to bacterial soft rot and fungal leaf spot infections. If you provide supplemental water, water deeply no more than once a week. Soaker hoses are preferable to overhead watering to avoid spreading leaf diseases from plant to plant.
Weeds
There are certain weeds and grasses that are so aggressive they can inhibit the performance or even survival of plants they invade (Canada thistle being one of them). Keep the weeds and grasses away from your irises.
Ill health
Irises that are diseased or under insect attack may not be able to bloom until the problem is eliminated.
Late freezes
Killing freezes that are severe enough to damage iris foliage within six to eight weeks prior to normal bloom can abort developing stalks even if the stalks are not yet showing above the foliage. .
Irregular bloomer
All irises are not created equal. While some irises may bloom very regularly in your garden once established, others may never do any better than blooming once every several years ... or perhaps never blooming at all.
Immature rhizome
Rhizomes will not bloom until they are mature. If you have planted smaller rhizomes, it takes a while for them to grow a bit before they'll bloom. Since you've had them planted in the same spot for 4 yrs, the last reason doesn't apply to your Iris....but I put it here for future referrence. They need to be adequately established. Some iris cultivars need a year or more to fully establish in their new locations before blooming. If you relocate them frequently, they may never become well enough established to bloom. Plant irises far enough apart to allow for several years growth before requiring division.
Good luck! Hope this is helpful.

Answer 2

Why iris often don't bloom:

1. The rhizomes (a thick bulblike stem that grows horizontally and produces roots) must sit partly above the soil. Sunlight on the rhizomes causes the iris to bloom. For this reason, you should not mulch irises.
2. Irises should be in full sun.
3. Irises should be dug up and divided every 3-5 years to avoid overcrowding.
4. Irises do not like to "get their feet wet". They like well-drained soil.
5. Don't overfertilize. Too much nitrogen results in lovely foilage but no flowers.

This is a good article on caring for bearded irises (you don't mention what type you have): http://www.bhg.com/bhg/story.jsp?storyid=/templatedata/bhg/story/data/Iris_082305.xml

My bearded irises belonged to my great-grandmother and are over 60 years old. I have moved three times, taking them with me each time.

Answer 3

They could be too crowded, try spreading them out if so. There could be more shade than you had the first year causing them not too bloom. Make sure you water well and you could try a fertilizer something that would stimulate the blooms.

Answer 4

sounds like too much nitrogen and not enough phosphorous. If you have been fertilizing them try feeding some bonemeal or other high phosphorous. That is the second number on the fertilizer bag. Like 5-10-10. The numbers are Nitrogen, phosphorous and potassium in that order, given in percent of total weight. Aslo if they have become too crowded it might be time to thin them. Used to thin mine every other year but crowding usually results in smaller flowers instead of no flowers.