They are about 8-10" apart, and none have been there more than three years,
most are two years in the same spot (and were scrawny the first year because
of being cheap corms from Lowe's.)

Sounds as if they might need to be dug "out" a bit.

"Jennifer Richards" wrote in message
...
"laurie (Mother Mastiff)" wrote:

Last year the iris bed (about 3 years old now and new corms added each
year)
bloomed PROFUSELY. I put some rotted chicken manure in their bed in
late
summer and mulched with pine straw. There was nly space to add two
new
corms.

A master gardener I know says that most iris need to be divided every
other
year in order to keep blooming. Perhaps your iris bed is too crowded?