Sharing the beauty of the Iris
The color of an iris often depends on the "eye" of the hybridizer. One iris may be called purple while a similarly colored iris may be called violet. For official definitions, go to https://wiki.irises.org/Hist/ColorCodes. Listed below are various "standard" flower color patterns.
Learn MoreIrises are very tolerant of neglect and seem to grow quite well without human help. However, for best growth & bloom, they appreciate good soil, water during dry times, fertilizing and weeding.
Plant irises in late summer to early fall, when nighttime temperatures remain between 40 & 50 degrees Fahrenheit or above. This gives them plenty of time to get established before the coming winter. The tall bearded iris varieties are best planted closer to fall because they go dormant in early to mid summer. If you received bare rhizomes or irises in a container at some point earlier in the year, go ahead an plant them as soon as convenient. It's better to get them in the ground rather than wait until the ideal time.
Irises bloom best in full sun. They can tolerate as little as half a day of sun, but it's not ideal. Without enough light, they won't bloom. Bearded irises should not be shaded out by other plants.
They prefer fertile, slightly acidic soil (here on the southern Oregon coast my soil is heavy clay, so I am constantly adding organic material, sand and other amendments to lighten the soil). Good drainage year round is important. Irises will tolerate wet feet (roots) nicely, but don't appreciate soggy soil.
Plant the rhizome horizontally with the top exposed (if your climate has hot summers, plant the rhizome just below the soil surface. Dig a hole @10 inches in diameter and 4 inches deep. Make a ridge of soil down the middle and place the rhizome on the ridge, spreading the roots down both sides. Fill the hole with soil and firm it gently. Water throroughly. Do not mulch around the rhizome as this may encourage rot in the rhizome.
Fertilize in early spring with an all-purpose fertilizer scratched in around the plants. Avoid applying high-nitrogen fertilizers. Reblooming irises perform best if fertilized again after the first wave of flowering is finished.
Taller irises may need staking or they will fall over. After blooming is finished, cut flower stalks down at the base. Generally there is no need to cut back the fans (leaves) after flowering as they need the leaves to prepare for next years growth.
If you plan to divide your iris clumps (usually every 2 to 5 years) wait until flowering finishes, Carefully dig up the clump of irises and separate the rhizomes that have both fans (leaves) and roots. Trim the foliage to 4 to 6 inches, inspect the rhizomes for damage or rot (you can remove the damaged parts). Replant the rhizomes or share with friends.
The Oregon coast doesn't have issues with iris borers, but we do have challenges with leaf spotting because of the moist climate. I treat my rhizomes with a fungicide before replanting to help stop the leaf spotting. I also spread slug & snail bait around the area after planting and throughout the year, especially around other bushes or plants where the slugs & snails hide during the day.
Now, sit back and enjoy your irises and their blooms.