The humble iris; The poor man’s orchid
By KATHRYN DORMAN
Hello, Clinton County!
I am writing for the Express for the very first time.
I have been a Master Gardener for two years. I retired in 2016 from teaching science and math in Keystone Central School District. I am now free to play in the dirt – all the time, if I have the ambition!
I have always liked gardening of any kind – flowers, trees, vegetables, houseplants – you name it, I try to grow it. Today, I am writing about irises, my favorite flowers. They are so graceful and elegant.
I grew up “back” of Beech Creek. We only had two or three different colors of iris – all purple. I knew irises were durable, because they were among the few surviving flowers on an abandoned homestead nearby.
After growing irises on my own for about 40 years, I can also tell you that they are easy to grow. I have so much to say about irises, that my article has been divided into two parts.
The iris is a perennial that gets its name from the Greek word for rainbow, because irises come in almost all colors, and are sometimes even multicolored. Most irises will survive at least in plant hardiness zones 4-8. Clinton County is in zones 5 (Renovo) to 6b. So, pick almost any species of iris, and it will thrive here.
The genus iris is a member of the iridaceae family. About 300 species of iris have been identified. According to the USDA Forest Service, 28 species are native to the United States. Different species have adapted to different conditions. Plants range from a few inches to over three feet high and range from 1-10 inches across. Irises can be selected to have continuous flowering from April through June.
The iris is a monocot. It has one leaf emerging from the seed upon germination. This structure contains nutrients needed by the plant until it can photosynthesize.
The iris’s flower parts grow in groups of three. Three sepals, called “falls,” droop downward. Three petals, known as “standards,” are more upright. The leaves are tall and sword-shaped.
Irises either grow by producing rhizomes or bulbs. Rhizomes are underground stems that grow horizontally. Bulbs store the plant’s food during dormancy until the next growing season. Bearded, beardless, and crested irises all grow from rhizomes.
The bearded iris has a fuzzy growth running down the center of each fall. There are six different classes, based on plant size and flower shape. The dwarf varieties bloom earlier than the tall varieties. The most commonly grown bearded species is iris germanica. Bearded irises grow best in well-drained, neutral soils, in full sun. Several varieties may rebloom in the fall.
Beardless irises have smooth falls and thin, grasslike leaves. Plants grow 1 to 4 feet tall. Most varieties bloom in June. Japanese (I. ensata) and Siberian (I. sibirica) irises are the most commonly grown beardless species. Both prefer slightly acidic soil.
Japanese irises require adequate soil moisture. Siberian irises prefer cooler temperatures. Another beardless iris species, the native Louisiana iris, likes wet soils.
The crested iris (I. cristata), has a small raised area, or crest, on the middle of each fall. It is native to eastern United States, and likes partial shade. Crested iris leaves are short (4 to 6 inches). Colors are limited to pale blue to violet varieties. Crested irises prefer infertile, well-drained soil.
The bulbous irises include European species such as the Spanish or Dutch iris (I. xiphium) and the English iris (I. latifolia). They shed their leaves after the blooming season, becoming dormant.
Irises can be grown from seed, but it is a tricky process.
Vegetative propagation of irises can be done by dividing the rhizomes or bulbs. Divide rhizomes any time after flowering until mid-September. In bulbous irises, this should be done during dormancy (after the plants die off). If you plan on replanting, you might want to mark individual colors before flowering ends.
Water plants often enough before blooming to keep soil moist but not wet. Gently remove weeds and grass around the rhizomes.
Apply a low-nitrogen fertilizer at least a month before blooming.
Mulch should NOT be used on top of rhizomes or near leaves. They need to breathe!
Cut each flower stalk to an inch or two above the rhizome after all flowers on it have bloomed. This prevents seed pod formation, and promotes vigorous rhizome growth. Do NOT cut iris leaves! The foliage is needed to build up food reserves for the next flowering season.
In Part Two, I will tell you more about my own iris beds. I will also provide tips on what to do with irises after they bloom, and how to keep iris beds healthy and blooming profusely year after year. If space allows, I will also discuss interesting uses of irises, along with a few cautionary tales…
Kathryn Dorman is a member of the Master Gardners. She can be contacted by emailing firstname.lastname@example.org