Could be they are planted too deep. Roots should sow slightly.
Iris like to have their rhizomes slightly above soil line so if they're completely underground or heavily mulched that could be part of the reason. I've found the less I mess with 'em the better they like it. I've even thrown some in the woods when I thinned them out and they still managed to live!!
Joy and Susan are correct about iris planting depth. Make sure you are not using a fertilizer that is high in nitrogen, which encourages foliage growth at the expense of blooms. If they continue to be recalcitrant, you may have to pull them out and experiment with other irises to determine the ones that are the best bloomers in your particular garden conditions.
Thanks guys. I've noticed they are quite under quite a bit of mulch.
Yeah - they kinda prefer being able to wiggle their toes in the dirt!! Move the mulch - I am much further north than you and I just let nature take its course - whatever leaves fall in the Iris bed is all the mulching I give them - then in late spring I clean all the dead stuff & rake the leaves and off they go!!! By next week they'll really be busting out!!
Yes, pull off all the mulch, Faye.
Thanks guys! my mulch came from having a tree cut down in the back yard and mulch flew everywhere with the stump grinding. Mulch removed!
Good Girl!! You get the GOLD STAR today!! ;~}
I was told by a breeder that they like the top third of their roots in the sun. because of all the rain we have had this year, weeds have overgrown some of them and they did not bloom.
Yes they are pretty picky about having their feet covered. I let someone help me break up a couple of large clumps of irises and I guess I did not make myself clear enough because the ones I moved bloomed this year. The ones he moved did not. Guess what I get to do. Oh well I have lots of healthy green.