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
Help!
I live in Claremont and cannot find any shade of brown iris rhizomes. Does Roger’s have any?
Hi Cheryl,
The brown and amber tones are going to be unlikely to be found in most retailers, including Roger’s Gardens. You will almost certainly need to order these through a mail-order source. There are many on-line suppliers, but I might suggest these two. Both are Oregon companies with a very good reputation.
Schreiner’s Iris Farm: http://www.schreinersgardens.com
Pleasant Valley Iris: http://www.irisfarmer.com
Good luck.
Confused – we live in Anaheim Hills. One place you state full sun for bloom – the other part shade. Thank you
Hi Kaye,
Sorry for the confusion. In most gardens, other than very hot interior locations, bearded Iris will do just fine in full sun. If you have a lot of reflected light, such as off of pavement, a nearby wall or other feature then I would suggest a little light cover from adjacent trees, shrubs or structure.
In Anaheim Hills, it will depend on this reflected light. If you are not certain, give them a little light shade and you will be fine.
I hope this helps. Good gardening.
Ron
Where should iris be planted in Sierra Madre?
Hi Mary,
In warm inland areas like Sierra Madre I suggest planting bearded iris in a bit of afternoon shade.
Ron
I live in Fallbrook I recently ordered reblooming irises from a midwestern bulb company. It’s been so hot I’ve been afraid to plant them. Should I wait for cooler days or is it ok to plant them now? Also, we have ground squirrels. Would it be best to plant them in containers?
Can they be crowded?
Hi Sheryl,
Glad you ordered rebloomers. That’s the way to go, especially in Southern California. In Fallbrook I suggest giving bearded iris a bit of light shade. Not heavy shade, but some protection in the afternoons.
I would plant your iris now or in the next couple of weeks. Iris are best planted when they are at their most dormant period, which is now, in the hot late summer or early fall. Also, your iris rhizomes will begin dehydrating if not planted soon. Unlike bulbous plants (daffodils, tulips, etc.), bearded iris do not store very many carbohydrates in their rhizome, so they don’t have a long shelf life.
Ground squirrels may be an issue. I’m not sure if they will prefer them or not, but would hate to find out the hard way. In my experience bearded iris perform much better in the ground than in containers. And ground squirrels won’t respect container grown plants any differently than those in the ground anyway. I suggest getting them into soil and making a small cage over them out of chicken wire and two or three stakes to hold it upright and in place. This is how plants are protected in natural areas when land managers are doing Native plant restoration and it does a very good job of keeping rabbits, squirrels, deer and other herbivores at bay until they get established. It is very effective. Be sure the cage completely encloses the plant’s; over the top as well. After they get established you can remove the cage and see whether the squirrels are interested in the iris or not.
Bearded iris are traditionally planted three-rhizomes-to-a-clump, each rhizome spaced a few inches apart with the growing tip of each one facing outward from the center in a twelve o’clock, four o’clock and eight o’clock arrangement. Don’t plant each rhizome singly or you won’t have flowers for quite some time. After about three years, and every three years thereafter, you will need to dig up the clumps and separate the rhizomes again, replanting three of them and removing the extras. Do this at this same late summer-early fall period. If you fail to do this digging and replanting you will see the clumps decline in their flower production. Lastly, don’t plant the rhizome too deep. Just barely cover the top of the rhizome with about an inch of soil, no more
That’s the quick answers to your questions. There are lots of other online sites with advice as well, just be sure it is regionally correct advice. Growing bearded iris in other climates can be quite different.
Good luck and good gardening.
Ron
Hi Ron,
Thanks very much for the region-specific information. I live in Silver Lake, just south of Glendale, in Los Angeles. Is full sun OK? I also have a bed with morning sun and then medium shade, if that’s better.
I love Frequent Flyer’s colors and will also look at the others you mention as good re-bloomers.
Thanks!
Hi Freda,
You could probably manage bearded iris in full sun in the Glendale area, especially if there is not any reflected heat off of surrounding pavement and/or reflective walls. However, the location in morning sun and moderate pm shade sounds ideal in your area.
‘Frequent Flyer’ might still be my favorite bearded iris, but I wrote that article several years ago, so there are now even more reblooming iris on the market to choose from.
Good gardening.
Ron
Hi Ron,
I moved up to Ventura right near the ocean about 4 years ago. Moved my irises ups here from Glendale and they loved it. Bloomed like crazy just about all year long. Last year I started getting a fungus spots on the leaves. Changed the sprinkler heads and watered by hand thinking they needed less water. This year – having even worse problems with the fungus. Used Daconil and a couple other fungus treatments to no avail. Blooms are down, now I don’t think they are getting enough water and I’m pulling my hair out! It’s time to divide them and I’m thinking that I will dig them up, then dig out the soil and replace it with some Amend and local soil from an area that doesn’t have iris. Then drench it with some more Daconil – wait a week or two and replant. Any thoughts?
Hi Lisa,
It sounds like your bearded iris are either undergoing a bacterial leaf spot disease of a fungal leaf spot infection.
Bacterial leaf spot (Xanthmonas species) would be my more likely diagnosis, based upon where you are. It is characterized by spots on the leaves that begin at the edges and grow larger, eventually showing a whitish center. Fungal leaf spots (Didymellina macrospora) do not grow in size, but eventually show a rusty red/brown edge around the spots.
Fungal leaf spot should be controllable with good air circulation and the daconil treatment mentioned. Cutting the leaf fans back hard and disposing of them in the late summer (about now) is also a good idea.
However, if you have bacterial leaf spot, the fungicide treatment will have no effect. Bacterial leaf spot is usually not treatable. Like many bacterial diseases, it is spread most often from infected plant-to infected plant through hands, pruning tool and gloves, so be careful with this. It is even spread within the same clump through hands and gloves as you are removing leaves. If you have other iris clumps be sure to sterilize your tools with a spray of Lysol between working on them. Sadly, you may have to dispose of these infected plants. Hope this helps. Ron