Bearded iris are misunderstood in the coastal gardens of southern California. Like many other peculiarities of local gardening, confusion begins with well-intended information written for a national audience. This confusion is compounded by large national iris growers that select varieties based upon criteria other than garden performance. Sadly, growers may select economics over garden success.
Let’s review some Bearded Iris assumptions. Keep score if you want. Don’t worry; no one is checking your assumptions. 1) Iris bloom primarily in April and May. 2) Iris should be bought and planted along with other fall “bulbs”, usually October and November. 3) Iris clumps should be dug and divided in fall or winter. 4) Iris go dormant in the winter. 5) Iris do best in partial shade. 6) Iris varieties that have won exhibitions and awards are a good starting point when selecting varieties for a garden.
As a coastal Southern California gardener let’s begin the discussion with bloom time. Yes, it is true that most bearded iris on the market are spring bloomers, about April and May. This is unfortunate. Why plant an iris that blooms only in spring if you could select a nearly identical variety that also bloomed in summer, fall and even winter? In southern California there is no reason to select these “once-blooming” varieties. Unfortunately, once-blooming varieties dominate our market.
Very few of the bearded iris available are truly repeat-blooming varieties. Even when the label says “repeat-blooming”, it is often incorrect. An iris may be a repeat-bloomer only a few miles away in Anaheim, but will not re-bloom in Newport Beach, and vice-versa. Commercial growers couldn’t possibly achieve labeling this detailed. To make an intelligent decision you’ll need to search for local information from a knowledgeable source.
‘Frequent Flyer’ is likely the best repeat-blooming bearded iris ever bred for our coastal gardens. A tall stately, glistening, ruffled white with a dash of yellow at the center. ‘Frequent Flyer’ usually gives me three to four bloom cycles per year. I know one coastal gardener who swears by five cycles a year. Other iris that reliably re-bloom in our area include ‘Mary Frances’, ‘Feedback’, ‘Summer Olympics’, ‘Victoria Falls’, ‘Grandma’s Purple Flag’ and ‘Frequent Violet’.
In mild climates, like ours, Bearded Iris never go dormant. They keep their foliage year-round, and with the right re-blooming selection, may have flowers nearly any time of the year. Nonetheless, the best time to plant or divide bearded iris is right now, during the hottest days of summer. Look away if you read about digging, dividing or planting bearded iris in the fall or winter months; this doesn’t apply in coastal Orange County.
Since bearded iris never go dormant in our area, they remain attractive all year. Use them in a garden as you would evergreen perennials, like daylily or agapanthus. Think of bearded iris more like you would penstemon, lavender, salvia or small phormium, rather than as “bulbs” like you would daffodils, ranunculus and tulips.
Clumps of bearded iris should be divided every three or four years. In Orange County, August is the perfect time to perform this simple chore. Dividing plants often frightens novice gardeners, but it is a simple process. Begin by pushing a shovel into the soil a few inches beyond the edge of the clump. Pull back the handle a bit to loosen the soil. Continue until the entire clump is encircled, then push the shovel all the way under the clump and force the shallow rhizomes upward. It’s ok if the clump begins breaking apart. That’s what you want.
Now, remove all of the rhizomes from the soil, knocking the soil off as you go. With your hands, break the living rhizomes away from the old rhizomes behind them. Live rhizomes will have a growth tip with leaves on one end. Throw the old, leafless rhizomes away. Now you’ll have a pile of fresh young rhizomes ready to replant. To prepare them for replanting, cut the foliage on each rhizome straight across at about six or eight inches.
Now re-plant the biggest five or seven rhizomes back into their original location. The rest can be planted in similar clumps elsewhere in your garden or given to friends.
In Orange County, especially in coastal locations, bearded iris are full sun plants. Contrary to some references, if you want flowers and healthy plants, keep them out of the shade.
Awards, medals and other honors are prolific in the iris community. The American Iris Society and other groups bestow many awards to iris varieties. The Dykes Medal, the Cook-Douglas Medal, the John C. Wister Medal and the Hans and Jacob Sass Medal are all “show” honors. However, these awards offer little indication of how an iris will perform in your local garden.
Don’t be misled with bad information or false assumptions. Select bearded iris that re-bloom in our area, plant them in a sunny location and divide the clump every three or four years. As a successful coastal gardener perhaps you are becoming accustomed to breaking a few gardening rules. If not, bearded iris are a good place to begin.
Ron Vanderhoff is the Nursery Manager at Roger’s Gardens, Corona del Mar