I picked up a bag labeled purple Dutch Iris at the garden give take day on the 28th. They are small bulbs. Should I go ahead and plant them now or should I wait?

I'd go ahead and plant them now. They tend to diminish over time here, but I think in your zone they should perform well.

Neal ~ Diminish isn't the best word...disappear is more like it for me. I don't know what I did wrong, or maybe they don't like my climate. I have planted hundreds of them, and I am lucky if I see one or two! I probably won't be planting any more. I can't afford to waste my time with such little results!

I have heard voles and other rodents eat them, totally disappearing makes me suspect something like that.

I am not sure. Where I planted them, there are no holes in the ground.