If you’re looking for a reliable, long-lived hardy perennial that gives you a myriad of gardening possibilities, is drought-tolerant, and sports sword-like foliage that intrigues even when the flower is not in bloom, look no further than the bearded iris (Iris germanica).
With about 200 species, the word “iris” means rainbow; appropriate in that it comes in blue, purple, white, yellow, pink, orange, brown, red, and even black. The flowers have six petals; three upright petals known as standards and three hanging petals with a fuzzy line running down the middle that are called falls.
The flower of the Greek goddess Iris, the messenger of Love, the numerous colors of the iris made up the rainbows she used on which to travel. Pliny, one of the very first men to develop the study of botany and recognize the medicinal properties of plants, praised the curative virtues of the iris. And in the Victorian language of flowers, the iris symbolizes eloquence. Knowing the history and mythology of the plants we bring into our gardens allows us to fantasize along with admiring them; perhaps a young 19th Century suitor found the words he wished to express to his lady love while holding a bouquet of bearded iris.
The optimum time to plant the bearded iris is in September, which allows it to become established prior to winter. Unlike the majority of spring bulbs, the bearded iris doesn’t require cold to produce blooms, thus making them perfect for temperate climates.
Prepare the soil as usual, then dig a shallow hole to accommodate the multiple rhizomes you will want to plant for a power effect. For each rhizome (which is a thick, fleshy underground stem), build a mound of soil, placing the center of the base on it. Be sure that each mound is slightly above soil level. Spread the roots around the mound, ensuring that they are pointed downward; this allows gravity to work in the plant’s behalf by drawing nutrients down to the root.
Provide the rhizome with good drainage, keeping the feeder roots below moist but not wet; in southern California, we recommend watering every 7 to 10 days. Mass plant them for dynamic color effect, spacing 8 to 10 inches apart. If you are planting in the fall, mulch for winter protection.
As irises multiply out from the center, which eventually dries out, plan on digging them up every three to four years, dividing them into new plants, and re-planting. Whether you’re planting purple iris (symbolic of wisdom), blue iris (symbolic of faith and hope), yellow iris (symbolic of passion), or white iris (symbolic of purity), your bearded iris beds will repay you for your efforts with ever more plants.
- Miniature dwarf – height is 8 inches or less, with flowers that are 1-2 inches in diameter
- Standard dwarf – height is 8 to 15 inches.
- Intermediate – height is 16 to 27 inches.
- Border – height is 16 to 27 inches.
- Miniature tall – height is 16 to 25 inches, with smaller flowers.
- Tall – height is 28 to 38 inches.
Fertilize, but in moderation; while nitrogen, potash and phosphorus are essential for successful growth in iris, too much nitrogen will make your plants more susceptible to rot diseases. As you survey with pride your iris garden, relish in the knowledge that The Dykes Medal, awarded annually to the finest iris of any class, has been awarded to the tall bearded iris more often than to any other class. So, keep in mind the gardening rule of building from short to tall for most effect.
By E.W. Forsyth, added 9/01/13