Do Irises all increase at the same rate, or no?

I'm more familiar with Daylilies, but looking for some info on how Irises increase. Do they all tend to increase at the same rate, or are they like Daylilies in that they are hybridized for different traits, and one cultivar might increase at a different rate than another?
Thanks!

Median iris which are the shorter varieties usually multiply much faster than the tall bearded one. Each variety is different. Once can increase like a weed, while others much more showly.

Hope this helps

D

Not only may one iris (even in the same class) increase much more quickly than another, but the same iris may behave entirely differently from one climate to another, one garden to another, or even from one spot in a garden to another spot in the same garden. There are, of course, cultivars that seem to be very vigorous clumpers wherever they are grown, and others that seem to be slow increasers everywhere. Most, however, vary to some degree depending on specific growing conditions.

I agree with D that as a general rule, median and dwarf bearded irises increase much more quickly than TBs. There are, of course, numerous exceptions to that observation.

Laurie

Thanks! Just as I suspected. I'll go browsing around the catalogs to see if they note "vigorous" growth, or "fast increaser" or somesuch language.

Some folks prefer to grow moderate increasers because they don't want to have to divide their irises every year or two. I personally prefer the most rapid increasers because I have found that in my very severe and difficult growing conditions, the irises that can quickly outgrow disease are the ones most likely to survive here.