Colorful irises, named for the Greek goddess who rode rainbows, can be found in a variety of heights and shapes. This June blooming is tough, dependable, and simple to grow, despite its divine roots. Take a look at our guide on how to develop and maintain iris blossoms.
Irises, or Iris
As many as 300 species of Iris can be found. The tall bearded irises (Iris germanica), which can grow up to 3 feet tall, are the most common.
These six-petaled flowers have three outer “falls” and three inner “standards,” each with three petals.
Bearded or “beardless” iris are two varieties of iris. As its name suggests, the bearded iris is known for their long, silky hairs that run along their falls. Instead, the hairs in the crested iris form a comb or ridge.
Early summer is the prime time for the majority of iris species to bloom. Retiring plants, such as bearded hybrids, are a common occurrence in the wild.
Butterfly and hummingbirds love to perch on irises, and they make beautiful cut flowers. Looking for iris friends? Try roses, peonies, and lilies in your garden.
When Is the Best Time of Year to Plant Irises?
This time of year is ideal for planting irises because the nights should be between 40 and 50 degrees Fahrenheit or above. As a result, they have plenty of time to establish themselves before the winter sets in. Because the tall bearded iris cultivars go dormant in early to mid-summer, they should be planted in the fall.
Plant bare rhizomes or irises that you received earlier in the year in a pot as soon as you get the opportunity. You should plant them now rather than wait for the perfect moment.
Garden Site Selection and Preparation
- Irises are best grown in full sunlight. As little as half a day of sunlight is OK, but it’s not ideal. They won’t bloom if they don’t get enough light.
- It is crucial that other plants do not shade out bearded irises, as many of these flowers thrive in a separate, isolated area.
- They prefer well-drained, well-drained soil that is neutral or slightly acidic in pH. Learn about soil preparation and organic soil additions.
- Irises enjoy “wet feet, but dry knees,” so good drainage throughout the year is critical. In the winter, they will not grow in moist soil.
- Till or garden fork the soil to a depth of 12 to 15 inches, then add a compost layer of 2 to 4 inches.
Irises: How to Plant Them
- Plant the rhizome horizontally, with the top exposed, for bare-root irises. Plant the rhizome just below the soil surface if you live in a hot environment.
- Depending on the size of the rhizome, plant it alone or in groups of three.
- Using a shovel, excavate a 10-inch-wide and 4-inch-deep hole. Spread out the roots of the rhizome on both sides of a ridge of earth, and then plant the rhizome. Make sure to leave a portion of the rhizome and some of the leaf exposed by filling the hole with soil and compacting it gently.
- Planting irises too deeply is a common mistake. In warmer areas, the rhizomes of these plants should be partially exposed to the weather or covered with a thin layer of soil. Too much digging will make them fail.
- To avoid encouraging rot, avoid mulching around the rhizome.
- Give everything a good rinse.
Iris Care Instructions
The best time to apply fertilizer is in early spring, just before the plants emerge from their winter dormancy. Rhizome rot can be aided by avoiding the application of high-nitrogen fertilizers or the careless mulching of organic debris. After the first wave of flowering is over, reblooming Irises perform best if they are fertilized again.
It is important not to overwater iris plants, as this might lead to root rot. Do not wait until the last minute to water, especially during the summer months when water supplies are at their lowest.
The rhizomes should be exposed. Instead of thriving deep underground as bulbs do, iris rhizomes require some exposure to the sun and some ventilation in order to dry out properly. They will rot if they are covered in soil or crowded with other plants. In the spring, irises may benefit from a little layer of mulch.
Staining taller irises may be necessary to avoid them toppling over.
In the foliage, keep an eye out for iris borers (dark vertical lines that may appear watery show up in the leaves). Below are some helpful pest control tips.
Bearded Irises flower in succession on buds scattered throughout the stems if you deadhead (remove spent blooms) regularly.
After the flowers have stopped flowering, cut the stems at their base, but do not clip the irises’ leaves. The photosynthesis of leaves continues each year, generating energy for the plant’s growth the following year. To prevent rot, remove the brown tips and cut the blooming stalk all the way to the rhizome.
Make sure to remove any leaves that appear yellowed or spotted after a strong frost in the fall and toss the rest in the trash.
Remove and destroy iris foliage that has been severely frostbitten to prevent the spread of borer eggs. See the frost dates in your area.
After the ground freezes, cover the rhizomes with an inch or two of sand and a thin covering of evergreen boughs for winter protection. Remove the evergreens in the spring when the Forsythias blossom.
Prevent Iris borers by removing winter mulch and any old leaf in the early spring.
Making Irises Divided
The rhizomes of irises may lose their vitality and stop blooming if the plants are overwhelmed. It’s time to divide and replant healthy rhizomes in new soil when this happens (typically every 2 to 5 years).
When should you split? After the flowers have faded, cut the foliage down to a height of six inches.
- Dig up the clump of irises as soon as they’ve finished blooming (about mid-summer). This “mother” rhizome has given rise to multiple offshoot rhizomes since you planted it.
- Use a sharp knife to cut the rhizomes from the mother plant, and then trash the mother plant, which will no longer bear flowers.
- Rhizomes should be examined for symptoms of decay or disease, and any infected sections or entire rhizomes should be removed and thrown away.
- Iris foliage should be kept at a height between 3 and 5 inches so that the plants can concentrate on growing new roots.
- Replace them where they were previously planted, or give them to friends and family to help spread the iris-loving spirit!
- Pests/Diseases
- Irises are drought- and deer-resistant.
- Yet the dreadful Iris Borer may lay its eggs in old leaves and survive the winter. Look for these bugs if you observe vertical streaks in the leaves! Dig up the rhizome if you notice indications of rot, and remove the afflicted areas.
- Pests like the verbena bud moth, iris weevil, whiteflies, aphids, slugs, and snails, as well as nematodes, can be a real pain in the neck.
Varieties to Consider
- The vibrant colors of the tall bearded iris types liven up the June garden. They are usually planted in the fall since they blossom in June.
- ‘Immortality,’ a tall bearded Reblooming Iris, blooms in June and again in the late summer with pure white flowers, is the perfect example of this. Zone 4 hardiness is required.
- If you live in Zone 4, you may look forward to the likes of FeedBack, Earl of Essex and I Do blooming all year long.
- In warmer climates, ‘Jennifer Rebecca,’ a mauve pink beauty, would be a good choice.
- I. sibirica, the Siberian Iris, is available in a variety of hues as well. Although more fragile in appearance than stately bearded irises, these iris are no less tough.
- I. ensata, a Japanese Iris with enormous, flat blooms resembling tropical birds, thrives near ponds. I. ensata
Wisdom and wit
French royal standard fleur de Lis features the iris as well as Florence, Italy’s symbol.
When teething babies were advised to chew on a “finger” of dried Iris ‘Florentia’ root for its natural fluoride, it was thought to alleviate blood and lung disorders.
