I have some german bearded irises growing around my mailbox.

There's a section of about 2'x2' surrounded by railroad ties. In there
is the post to the mailbox, and the rhizomes from the irises. The dirt
is completely filled in with iris rhizomes (they've been growing there
something like 8 years).

I used to get many stalks of iris blooms, but, in the past two years
I've only gotten one "stem" of blooms per season. I think it might be
that they're too crowded.

Is there anything special I should do to separate them? Just dig out
"all" of them except one or two rhizomes? Should I leave a clump and
then free a section of a certain size, so, I effectively 'patchwork'
in blank areas?

What I'd like to do is remove the least amount of rhizomes for the
most amount of blooming return next year. If that's all of them, then,
that's fine, but, I don't want to pull out all of them unless that's
really the best choice.

Second to that, I have a new lot of mixed (by color) iris rhizomes
that I bought. How far apart should I plant them in a long thin bed
that will still leave room for other small flowers in between (I have
some snowdrops and grecian windflowers, and other 'small' bulbs that
grow into small plants)?

Gwen