By Carol Sindelar
At the June 10 meeting of EIPS, members requested I submit an article to the newsletter about Iris since I had already done the research for the meeting presentation. While I was looking at the information there seemed to be more to be said. So here it is.
There are several varieties of Iris:
Bearded - The biggest and boldest are the Bearded Iris also known as German Iris, Iris germanica. The Bearded Iris is the only one that has the fuzzy beard on the falls. They come in the most colors and combinations of colors and heights, dwarf, standard, table, and boarder. And the newest addition is the reblooming, blooming in the spring and in the fall.
Siberian – Often remembered as the tall slender Iris with the smaller flower, but often planted with the Bearded Iris. Iris siberiaca offers new colors every year but are mostly seen in a rich purple, blue or white.
Water Iris – The Iris pseudacorus (Yellow) and Iris versicolor (Blue) are both naturalized in North America and especially in Iowa. The yellow is native to Europe and the blue to North America. The yellow is taller (36 inches) and more vigorous than the blue. And I have felt the yellow’s pedals are longer making the blossom larger. These are the ones for the pond, both species like wet feet.
Louisiana – This iris is a native to Louisiana and are said to be amazingly easy to grow for zones 4 – 10. They need 4 – 6 hours sun and plenty of water. They also demand fertile, acidic soil. The blossoms are the size of Siberian but flatter, the stands go out instead of up and their colors are more intense, redder reds but still not a true red. They bloom later than Bearded Iris and can extend your growing season considerably.
Japanese – Iris ensata is the latest bloomer of all the Iris. They are zone 4-9 and require moisture-retentive soil. The flower also has a flat look with the stands as well as the falls reaching downward and the crest arching up and outward. “Shogun” is a true red.
Iris pallida aurea-variegata – Like the bearded but with a variegated leaf.
Whether you are keeping Bearded, Siberian, Louisiana, Water or Dutch, all Iris have a basic anatomy for the blossom.
Stands – The pedals that stand up forming the top of the flower.
Falls – The pedals that reach downward from the center of the flower.
Crest – The short, sturdy, inner pedals that lay inside the stands.
Beard – The fuzzy strips on the center of the falls. (Only on bearded Iris)
Since Iris is from the Greek for Rainbow, the colors in Iris cover the painter’s pallet, from reds and purples to blues, to yellows, rusts, pinks, peach, cream and even black. Although the red of the Bearded varieties of “Red at Night” and the black of “Superstition” are not true black and red, the black is close. There is no true green in any of the iris varieties, yet. Irises have special names for many of the special color combination as follows:
Self – The Iris is one color. “Beverly Sills” is a real popular peach colored Iris, all peach.
Bi-Tone – The Iris is two shades of one color. “Proud Tradition” is an Iris with dark blue falls and light blue stands.
Bi-Color – The Iris is two colors. “Edith Wolford” is an Iris with purple falls and creamy yellow stands.
Variegata – The Iris has yellow stands and rust or red falls. “Gypsy Caravan” is a Variegata Iris.
Amoena – The Iris is a bi-color but the stands are always white, with contrasting falls. “Dover Beach” is an example of an Amoena.
Blends – The Iris in the blends group include the Zebra and Batik group. The colors are streaked or blended over both the stands and falls.
Plicata – The Iris has light colored pedals with dark boarders.
For Iris, like many perennials, there is an optimum time to plant and transplant and then there is the time that we have. The best time to plant and transplant is one month after they bloom. Around here that is late June. The Optimum window runs through July. This is the time that the Iris is dormant, in the heat of the summer. After this rest, the Iris will sprout new roots and leaves and do some growing of new rhizomes and roots before winter sets in. Iris can be moved anytime but you must remember the move may affect the timing of the bloom that year or the next. Seldom does it kill the plant. Garden centers offer Iris both in the spring and during the late summer. Catalogues seem to think later is better as I have received Iris to plant as late as November, but usually in October. I don’t like them being planted this late. I usually loose a 3rd of the order and attribute it to the timing. And I also think it affects their ability to bloom the next year. But that is just editorial commentary. The bottom line is, plant them when you can get them. Move them when you have to or a month after they bloom if you have the luxury of scheduling the move.
Iris like to have their rhizomes close to the ground’s surface with the roots reaching down into the ground for stability. The best technique it to work the soil in a 10 inch hole then create a ridge for the rhizome to sit on. Allow the roots to extend into the holes on each side. Cover with dirt. The rhizome should be right at ground level. If you have problems with root rot, a gardener in New York recommends surrounding the rhizome and covering the top of the root area with sand. I don’t have this problem but it sounds like a good idea.
Another problem is Iris Bores. Fairly common in the Bearded varieties. We have also found them in our Water Iris. The older varieties of Bearded Iris might seem immune to bores but the reality is that they reproduce so quickly, that they keep ahead of the losses from bores. Newer varieties are more susceptible to the bores by not out reproducing their destruction. The life cycle of the bore is much like a butterfly or moth. Eggs are laid on the tops of the leaves in the fall. They hatch out as the bore, which is quite small and hatches out right before the time the Iris are blooming. Brown spots and holes can be seen on the leaves as the bore works it’s way down the leaf to the rhizome. Along the way it eats the leaves and grows in size. By the time it reaches the rhizome, it will be pink and the size of an adult’s little finger. Iris Bores are hard to eradicate.
Following are some suggested methods:
*Spray early in the spring and weekly until they bloom with malathion or diazinin directing the spray toward the bottom half of the leaves. A little liquid soap or detergent added to this solution helps it adhere to the leaf.
*Spray early in the spring and weekly until they bloom with Murphy’s Oil Soap (1/2 cup MOS to 1 Gallon of water). The lady who suggests this technique says she thinks the smell of the soap repels the bore.
*Which ever spray you use, it is recommended to remove (burn, not compost) old leaves and stem both in the fall and early spring . Also cut the leaves back to 4 inches after they bloom. This can catch some of the bores as they move down the stem. Watch for signs of their activity.
*Squeezing the leaves in the spring can smash the bore within the leaves.
So basically, we want to remove the dead leaves whenever we can to get the eggs out of the garden (November, March, mid summer). We want to remove the bores whenever we detect their presence.
Watch for browning leaves and obvious signs of the leaf being eaten, from the inside. Whether it be smashing them within the leave in April and May or cutting down the leaves to 3 inches or less if the bore is lower than 4 inches, after the Iris bloom. Cut them down again in very early spring, before they start growing for the year.
Dig out the roots if the bores get to them before you get to the bore. When you are transplanting Iris, soak the rhizomes in a solution of 10 parts water to 1 part bleach for one hour, then plant. This will kill off any bores or eggs, and disinfect the rhizome for fungus and root rot. This is especially a good idea when getting roots from friends. Don’t let them bring things into your garden.
I like to dead head the stems so the plant does not expend it’s energy on developing a seed pod since they reproduce very well by growing new rhizomes each year. The water Iris germinate quite easily, I have to dig them out of the gravel path along the pond each year. And I know the Siberians have seeded out into my Hosta that are down the hill from them. Watch for them, the seedlings look like a thick blade of grass. They take a couple years before they gain the height and stature of an adult plant.
Enjoy your Iris. Experiment with different varieties. Get addicted.
The American Iris Society votes on a favorite Iris variety each year and four of the last five years “Dusky Challenge” a Blue Self with Ruffles won this award. This is a beautiful plant and readily available in this area. The American Iris Society web site is: www.irises.org. It is a great source for information, it lists local organizations and has a very nice picture gallery.