good beginner info

I've had a few unnamed Tall Bearded Iris for years. They kinda took care of themselves. In the last few months, I've accumulated some newer named varieties. I need some basic info:
When do you cut back the green (if you do) ?
Do you treat for bugs / borers?
When do you divide?
What type of name tags do you use?
Is it true that the old blooming tuber only blooms once?
thanks
charlotte

I don't cut back healthy green foliage at all unless I am digging and dividing. Even then, I cut back only enough to help the plant remain upright until it is firmly rooted again. The plants need their foliage to continue to feed themselves for next year's bloom.

I do treat for borers with Merit granules in early spring. I have noticed Merit also seems to be effective at eliminating aphids in the iris beds. Unfortunately, Merit doesn't deter iris weevils at all, so I pick and squish them by hand.

Dividing is done on an as-needed basis depending on the vigor of each particular cultivar and the condition of its soil. Depleted and/or compacted soil needs to be dug and amended, even if the iris clumps residing therein really don't need dividing yet. Overcrowded clumps that start to diminish in bloom will be divided. In my short-season, cold winter climate, I find dividing immediately after bloom to be the best option. In a very hot, humid summer climate, it would probably be better to wait until temps cool in late summer/early fall.

I buy used miniblinds at rummage sales and cut them up for garden markers. I cut one end of the miniblind slat into a point to make it easier to push into the soil, then write the name of the cultivar using a paint marker on both ends of the slat. That way if the above ground part of the marker gets broken off, the underground section will still be able to identify the plant. Of course, I also make maps of all my iris beds so when markers go inevitably missing, I still know what's planted where.

Yes, each individual rhizome will only bloom once in its lifetime. In most cases, the rhizome with also produce additional rhizomes (increases) from around its sides. These increases will then mature and bloom and produce increases of their own. That's how one rhizome eventually becomes a clump. Occasionally, a rhizome will bloom and never produce any increases. This is a condition known as bloom-out and will result in loss of the plant.

Laurie

Thank you Laurie, So for the most part when I divide a clump I will throw away the old "mama" tuber.
charlotte

The old mother rzs will often continue to grow more increases even though they won't bloom again, so if you have the room and don't mind waiting for increases to mature to blooming size, they're worth replanting. The reason most folks discard old mothers is because by the time they divide a clump, the clump will provide a whole lot more unbloomed rzs than the gardener wants or needs, anyway.

If you put all those mothers in a paper bag on your curb with a "free irises" sign next to it, I imagine someone will snatch it up pretty quickly.

Laurie