How many hours of direct sun do they get each day? What kind of fertilizer do they get?

Rhizomes should be planted 1-3" deep, but after three years in the ground, they would most likely have adjusted their own planting depth anyway. Sibs perform best with at least 6 hrs of direct sun a day, ample water in spring before bloom, mulch, and a rich, acid soil.

Like beardeds, some Sibs take a long time to settle in before they resume their regular bloom cycle. Just this morning I had a bearded iris bloom for the first time since I planted it in 1999!

Unless you are growing your Sib in too much shade or in alkaline soil or with some other obvious cultural problem that can only be corrected by moving the plant, don't move it until it blooms. Sibs resent transplantation. Each time you dig and relocate it, you'll set it back and delay bloom again.

Laurie

Janet,

Caesar's Brother is arguably the most frequently misidentified of all irises. It seems that everyone who grows a purple Sib wants to call it CB. I have read that there are so many CB imposters now being circulated in both commercial and private gardens that it may be impossible to determine which is the true CB, or even if the true CB still exists at all. It's certainly not surprising that you may have three entirely different irises growing in your garden under the name of CB.

Laurie

I have exactly the same problem. I bought CB probably close to 10 years ago and if it has ever bloomed, it was so long ago that I've forgotten about it. I do know that it was located where it didn't get enough sun at first, so I transplanted it several years ago. It now gets sun all morning and much of the afternoon. I haven't done a soil test to determine what the ph is. The plants have increased a lot in size, but they did that before I even moved it. How patient must I be? And since the clump keeps increasing in size, how much space must I allow??

Ok guys, I think it might be a sun thing. At my house they always bloom, and are mostly full sun. The earlier the sun, the sooner the bloom, but must have afternoon sun I believe. I took some to work in early spring and planted them and they bloomed 3 yrs ago, (first year) but have not since. Plenty of foliage, and got about 20" in diameter. These don't get afternoon sun though after about 1pm or maybe a bit earlier. I have not tested the soil, but at work some are in good garden compost and some are in central Illinois clay. All get Preen around them, but so do the ones at home, so I don't think that is a factor. Good luck. If I get blooms this year, I will return with hopefully more answers, but the ones at home are now blooming and no signs at work.

CB is hardy, vigorous and prolific here. It produces many buds. These four-year-old plants are over three feet wide.

They get eight hours of sun per day. I throw a few handfuls of Garden Tone around them each spring. My soil is rich and mildly acid.