Newbie Bloom Problems

I am lucky enough to have a big natural pond on my property. All I want is some gorgeous TBI's to grow at it's edge, where the soil is a little thin due to the tree roots. I purchased and planted about 10 rhizomes 2 years ago. The first year, only one bloomed: Immortality. This year, the foliage came on beautifully strong on every rhizome and I expected blooms galore, but I have only ONE that is blooming! Immortality is nowhere to be seen. WHY? They are in a lovely sunny spot, and I've kept them mulched. Should I adjust the fertilizer? Is it too late to see more blooms this year?

Also, the original owner of the house planted a TB in the middle of the lawn. It is a beautiful blue and white batik type, BUT it only blooms every 3 to 5 years (I've owned this house for 15 years, this rhizome must be 25 years old.) It is blooming this year, luckily. Any ideas why this is happening?

Tall bearded iris don't like their bellies covered, nor do they like being crowded. Pull the mulch away from them. Poor drainage and wet roots equal rot.
Not every iris will bloom every year, they bloom only on new growth.
You may wish to try another type of Iris for the pond's edge.

Grannymarsh is correct in everything she recommended. Bearded iris rhizomes may refuse to bloom if they are buried under mulch or soil. Remove the mulch and make sure the tops of the rhizomes are level with the soil surface.

Both under and over fertilization can cause problems with irises (and other garden plants), so have a soil test run before you fertilize. That's the only way to know what your soil needs.

Thank you! Is there another type of iris that might be happier (i. e. bloom more readily)? I see clumps of beautiful iris in people's yards blooming furiously at this time of year, but I don't know what kind they are. I would love a good pink cultivar.

At the edge of a pond why not try Louisiana Iris or Japanese Iris. Both can provide a nice pink and love having their feet wet.

We had a late hard freeze that ruined most of my iris blooms this year. Only about 60 stalks on 325 clumps. :( Weather can be a factor of non-blooming too.