I just received a shipment of iris bulbs in Austin Texas in December; can I plant them now?

Yes. In Austin you would be able to plant them most anytime in the winter. The sooner now, the better and more likely you will get bloom from this spring assuming they had set bud formation from your source. In any case, better to be in ground than waiting. The roots will grow soon, even if you get some cold spells. Don't water too much. You should see new center growth in a week or two. Good luck.

Hmm. I lived in Austin for a number of years and had maybe a dozen separate large iris beds. However, they were all planted by the owner who built the house in the 1930s and my ex was the second owner. He bought the house in 1972 and the iris beds were still growing strong. So at least that's encouraging as far as 'iris survival'.

I wasn't a gardener then but here's my best guess. If the weather is decent, I'd plant them. Or if you're hesitant, plant them in containers. You can leave them in the pots or plant them in the ground later on. If I remember when I go outside later, I'll take a picture of some that I've kept in pots for way too many years.

I live in the Dallas area now. The nurseries that sell irises do so in the fall. Since our climate is generally a little colder than Austin's, my guess would be to plant them.

@Bubbles - do you know some good resources to call? Do the Master Gardeners have a help number? Or the Wildflower Center?

EDITED: I see that Donald gave you a good answer before I blathered on.

Actually, the National Convention of the American Iris Society was held in Austin several years ago. It was hosted by the local chapter in Austin. I hope the link works. It has some names/email where you can contact them. Should be an excellent source of information. http://www.kenfuchs42.net/isa_...

Thank you everyone for your answers regarding the Iris plants..

I just skimmed the link that Donald provided. In fact, I went straight to November 2018 issue and noted 2 things. First, the club had their sale in November but later had their show in April.

Then I looked at October. It said that irises love cold weather.

I have some irises that grew in the shade. They just kinda snaked around on the ground until they reached a point where they could poke their heads up and bloom. (yes, they prefer sun)

Here's mine but some in Austin were in really deep shade.
Squint to see them.