Jan,
Have not used it on iris yet but Epsom Salts is magnesium. That is a catalyst for many plant processes.

I have used a homemade fertilizer made from epsom salts, beer, & ammonia to get stubborn Christmas Cactus to bloom.

It will also help plants begin to absorb other nutrients, produce chloriphyl, start new growth and many other plant activities. Everything I put that homemade fertilizer on kicked into growth and/or set buds within one week of the 1st application.

What proportions did you use Berrytea4me?
Did you dilute it with water or was beer the primary liquid?

Oh, yes you dilute it with water. It actually goes a long way.

Here is the recipe:
12 oz. of beer
1/2 cup household ammonia
1 cup Epsom salts
2 cups of water (making a quart or so)

for epiphyllum diluted to 1 Tbsp. (1/2 fl. oz.) in a gallon of water used every two weeks. Double strength for other plants.

I have seen a similar recipe specifically for daylilies. Have never seen anyone mention using it on iris though. My experience with other plants is that they usually love it.

Sounds like a great recipe! Can this be used on most flowers?

janinecollette,
Yes, I use it on everything. Have not noticed anything that did not like it. Really greens plants up and develops buds in a hurry.