Water them. If you expect a decent show of bloom they need water. Dry summers & wet winters is the rule for all spring bloomers.

This is a So. Calif. response to a So. Calif. person. Since you planted them in your rose beds, your normal watering of those beds will take care of the Dutch iris. Of course, you should water them right after you plant to settle the soil around them. Things like daffodils, Dutch iris, and most other spring bulbs will start out putting down roots, then you should see shoots in the winter for us. Tulips and hyacinths are better off being in the fridge for ~6 weeks before planting, and rarely come back for us, given our lack of winter chill.

Thanks, Moses and Susan. Yes, I did water the bulbs when I planted them.
I tried growing tulips in the past, but no luck — until an exceptionally rainy winter brought them up! Probably wouldn’t happen this year.
I want the iris for color and interest after the roses are pruned inJanuary. Can’t go through three months with no blooms at all.😁