Years ago I was a member of the local rose society. One of the members had a marvelous backyard garden and came up with a counting guide...it ended up on the old Gardenweb Forums. I have kept the guide and feel it could easily be adapted to counting iris, or any type of plant....enjoy
HOW TO COUNT ROSES -- Kim_SC at Gradenweb
1. Mini roses don't count.
2. Floribundas - because they are not full-fledged hybrid teas they count as half.
3. Shrubs, Climbers, Ramblers, Old Garden Roses, etc. don't count because they can be considered "landscaping."
4. Roses not planted or in pots don't count. (See the "Territory" Clause).
5. Roses that were discounted count as half.
6. Roses received as gifts don't count.
7. Odd numbers must always be rounded of f. If you'reout of room, round the number down. For every one-hundred, divide by two. This is known as a "stock split."
8. Roses whose names you don't know or can't remember obviously don't count.
9. Roses that are on Shovel Prune Watch don't count; the roses that replace them also don't count as they cancel each other out.
10. Duplicate/multiples count as one as they are considered a set.
11. Roses that are not planted in a bed don't count. (See the "Landscaping" Addendum).
12. Bareroots don't count because they are dormant when they arrive; once you plant them and they start to bud out; well, you've already done your count, so you will just have to wait until next season by which time you'll be sure you already counted them.
13. Mislabeled roses don't count because you probably already have one of them somewhere, which has already been counted once…probably.
14. Anything less than Grade 1 counts only a fraction, and since fractions are not whole numbers they can be rounded off (remember the rounding off rule).
15. Roses that you think you might give away can be excluded from the count. It makes it easier to part with them; if, by some chance you wind up keeping them, well…oh well.
16. HTs that get huge and wind up taking more than one space should be counted twice, but remember the duplicate rule.
17. Now. if, after counting, you have under a hundred roses, you must immediately place some orders and they don't count because they're in transit and therefore not in the ground.
18. Roses ordered on a whim really don't count because they were never on a list. (This is known as the list rule: If it's not on a list, it doesn't exist most likely).
19. If you cut many roses and give them away, this is considered Charity, and everyone knows that you get special allowances for Charity which brings us to
20. Tax Deductions (see Claiming Roses as Dependants).
See? You really didn't have as many as you thought you did time to go order some more.
Adapting this counting guide for iris.....I have 3. I rely heavily on #6, #8, #10, #11 and #13. Now I'm wondering why it takes so long to weed them.
but I still love them all and they love me back 
. I have yet to discover how our nuttiness can become a threat to anyone... 
Ed, now I know I don't count any of
)
