New at iris growing

My irises are two years old - do they need to be divided yet? What should I do to get them ready for winter? I didn't do anything last year and they didn't bloom much and the blooms were small - but we had a freak late frost,too. They were beautiful the first year, large blooms, bright white with deep purple "veins." Anyone know what kind they are? A friend gave them to me and she didn't even know the name, though she grows all kinds of irises.

Bearded irises typically need to be divided every 3-4 yrs, though there are particularly vigorous cultivars that require more frequent division, and there are less vigorous ones that require less frequent division. The rule of thumb is to divide them when you see a diminishment of bloom.

In your case, however, there was a specific cause for your minimal bloom this year - the late frost - so I wouldn't divide them yet unless the clumps are really overcrowded or unless you made a planting error like planting the rhizomes too deeply or situating the plants in an area with inadequate sun or drainage. Even so, it's really too late in the season to be disturbing your clumps and replanting them now.

You don't need to do anything to prepare your irises for winter. In early spring, though, before temps reach 70 degrees, remove and trash or burn all of last year's foliage and any plant debris around your irises. That will remove borer eggs before they have a chance to hatch and start feeding on your irises.

From your description, it sounds like you are growing one of the many purple plicata-colored bearded irises. There are hundreds of registered purple plics on the books, so it'll be impossible to provide you with a specific identity. Just enjoy them as the nameless beauties that they are.

Laurie