Irises are not as popular as they should be. The beauty of their flowers is unparalleled and most types can grow in either sun or shade with little water. Yet they are not seen in gardens nearly as often as far more finicky plants.
The main reason you do not see more irises in gardens is their near absence from nurseries and garden centers. I believe this is due to the fact that irises are not easily grown in containers on account of their summer dormancy. In summer, any excess soil moisture will cause their rhizomes (semi-underground storage organs) to rot. When you pass the bins of tulip, hyacinth, and daffodil bulbs during the fall, you may come upon iris bulbs as well, but iris rhizomes, whose garden longevity and orchid-like flowers give them distinct advantages over iris bulbs, are seldom seen.
When it comes to storage out of the ground, iris rhizomes are problematic due to their susceptibility to fungus disease. If you wish to store iris rhizomes, it is necessary to dust them with sulfur or, once again, they are likely to rot. Although this sulfur treatment is recommended for storage of bulbs, tubers, and corms generally, it is imperative in the case of iris rhizomes.
It would be easy to fill a garden with a spectrum of irises since there are more than 250 species of them, most of them native to dry climates like our own. They grow from either rhizomes or bulbs but the tough irises that endure in our gardens are invariably of the rhizomatous type. I have had personal experience with the following iris species:
1. Iris germanica and related hybrids
This is the common flag iris or fleur-de-lis, with thousands of cultivars available in every color and combination of colors you could imagine. Most cultivars bloom briefly in late winter or spring, but some cultivars, known as remontants, will flower on and off in summer and fall as well. Flag irises are easy to grow and are as nonchalant about water as most California natives and cacti. However, fertilization and some additional watering now and then will lead to more foliage and flowers, especially in the remontants. There are many Internet vendors with a wide variety of flag irises for sale.
2. Iris douglasiana
The habitat of this California native, known as Pacific Coast iris, stretches from Santa Barbara in the south to Oregon in the north. Here, Pacific Coast irises require some sun protection in order to thrive. There is a wonderful selection of Pacific Coast cultivars available at the Theodore Payne Foundation nursery in Sun Valley.
3. Iris pseudacorus
Known as yellow flag iris, this is a species that, planted on the edge of a pond, will grow with weedy abandon. It is also suitable for planting in narrow, north-facing beds that are shielded from hot sun. Yellow flag iris grows taller with foliage that is more lush than that of other iris species listed here. I have seen this iris growing along the zigzag bridge in the Japanese garden at the Tillman Water Reclamation Plant in Van Nuys.
4. Iris cristata
So-called crested irises grow in evergreen clumps in the shade. Plants reach no more than a foot tall. Flowers are typically white or lavender and fragrant, with golden crests on each sepal.
5. Iris hollandica
This is the classic Dutch iris, the one you see in van Gogh paintings. Colors of this bulbous iris vary, but the standard bearer is purple or royal blue with a strong blotch of yellow on each sepal.
6. Iris foetidissima
This plant goes by the unromantic name of stinking iris, alluding to the odor emitted by its crushed foliage. For irises, its flowers are ordinary. Instead, its ornamental feature happens to be vivid orange-red seeds which, clustered at more than 20 per pod, create quite a stir when dozens of pods open simultaneously on mature plants.
7. Iris hieruchamensis
In late winter or early spring, if you find yourself hiking in Israel between Dimona and Yeroham, in the northern Negev Desert, you are likely to encounter your fair share of Yeroham irises. These are dwarf bearded irises, seldom more than a foot tall, whose colors range from bronze and burgundy to purple and black.
I have found that eBay.com is an excellent source not only for finding irises (and almost any other plants, for that matter) to purchase, but as a Web site where the different types of irises may be viewed and appreciated with just a few clicks of your mouse.
On Chandler Boulevard near Woodman Avenue in Valley Village, there is a heart-stopping eruption of white that no plant lover should miss. This fragrant botanical geyser, with long arching jets of white blossoms, reaching 15 feet into the air, appears to have shot up suddenly, without reason.
Lo and behold, it turned out to be a California privet (Ligustrum ovalifolium).
No one knows how California privet got its name since it is native to Japan. Nevertheless, it certainly does flourish in the Valley when allowed to grow without restraint. Up until now, the only California privets I had ever seen were growing in hedges. Such controlled growth barely allows these plants to flower.
TIP OF THE WEEK
I had never seen an authentic catwalk until visiting the California native garden of Susan and Daniel Gottlieb. Although I came to inspect an impressive collection of native plants, it was the catwalk that grabbed my attention.
Constructed above a slope along the back side of their property, the catwalk consists of a series of tunnels made from wooden planks covered with chicken wire.
Appropriately, one of the most stunning specimens in Susan Gottlieb’s collection is a Catalina cherry, a tree with highly decorous catkins (catkin comes from katteken, the Dutch word for kitten, a reference to the softness of this hanging flower cluster, that resembles a cat’s tail).
Catalina cherry (Prunus ilicifolia lyonii) is notable for its resistance to oak root fungus, as well as being attractive to birds that feast on its reddish-black fruit.