Iris is a genus of 260–300 species of flowering plants with showy flowers. It takes its name from the Greek word for a rainbow, which is also the name for the Greek goddess of the rainbow, Iris.
Some authors state that the name refers to the wide variety of flower colors found among the many species. As well as being the scientific name, the iris is also very widely used as a common name for all Iris species, though some plants called thus belong to other closely related genera. A common name for some species is ‘flags’, while the plants of the subgenus Scorpiris are widely known as ‘Junos’, particularly in horticulture. It is a popular garden flower.
Types of Irises
There are three general types of iris plants: Bulbous Irises (Iris reticulata and others), Beardless Irises (Siberian, Japanese, Spuria, Louisiana, and others), and Bearded Irises (Iris germanica). Each type has its characteristics.
- Bulbous irises are small, spring-blooming flowers with tubular flowers that come in a variety of colors. They grow from bulbs planted in the fall.
- Beardless irises bloom in late spring with sword-like foliage and either flat or cup-shaped flowers. They grow from roots.
- Bearded irises bloom in mid-spring with ruffled flowers on top of sword-like foliage that grows from thick rhizomes.
The most common type of iris is the bearded iris. This type has a fuzzy beard-like area along the center of each blossom.
Like all Irises, bearded irises have three different parts:
- Sepals – The sepals look like petals, but they’ve actually modified leaves that protect the flower before it blooms. The sepals will turn brown if you allow them to dry out.
- Petals – Three petals stand up and three hang downward. The upright petals are called standards, and the hanging ones are known as falls.
- Style arms – These are slender protrusions that extend from the top of the ovary.
Iris is among the easiest plants to grow in the garden. They are hardy, require little care, and are long-lived. The plant’s showy flowers appear in a wide array of colors and flower shapes.
Difficulty: Moderately Easy
- Choose a location that gets full sun for the best results. Iris plants tolerate part shade but will not produce as many flowers. Iris plants prefer well-drained soil that has been amended with organic matter such as composted manure or leaf mold.
- Dig a hole large enough to accommodate the rhizome and its roots. Place the rhizome with the roots spread out vertically in the hole and cover with soil so that it is buried about 1/4 inch deep in heavy, clay soil, or up to 1 inch deep in sandy soil. Plant multiple iris rhizomes about 6 inches apart to avoid overcrowding them as they grow larger each year. The rhizome should be planted horizontally with the top of the rhizome at or slightly above the surface of the soil line.
- Water your new iris plants well after planting to establish good root contact with the surrounding soil and to settle any air pockets that may have formed during planting. If they receive plenty of water while they are growing, they won’t need as much once they are dormant in the summer months. If you live in an area where more than 50 percent of your annual rainfall comes during the summer months, your plants may require additional watering to thrive.
Iris plants are beautiful, easy-to-care-for perennials that make an excellent addition to any yard, flowerbed, or container garden. There are lots of different varieties, so you’re sure to find the perfect one for your space!
* Plant irises in a sunny spot with well-drained soil.
* Water them regularly—they like moist soil.
* Fertilize each year in early spring (before they bloom) with a balanced fertilizer like [fertilizer].
* Prune off old leaves and dead flower stalks after they’re done blooming.
* Keep them safe from slugs and snails by sprinkling crushed eggshells or grit around them.
* Don’t plant irises in shady spots or poorly drained soil—they’ll rot!
* Don’t water them too much—too much water will also cause the roots to rot. The best way to tell if they need water is if the leaves start wilting. If that happens, give them a deep watering until the leaves perk up again.
* Don’t fertilize at any other time besides springtime—this can stress or shock the roots and will make it hard for them to thrive.
Plants are great for adding a little greenery to your outdoor space during the warmer months. Plus, propagating plants is a fun and easy way to get some new greenery into your garden without having to buy new plants.
So you want to grow irises?
It’s not as challenging as it seems, and once you have a patch of these flowers thriving in your garden, you’ll know that it was all worth it.
Here’s how to do it:
1. After the last frost of spring, fill a pot with soil and plant an iris rhizome with the growth buds facing up.
2. Let them develop roots for about four weeks, then plant them in your garden about 12 inches apart, making sure they are facing south so they get plenty of sunlight.
3. Plant the rhizomes 2-4 inches deep in the soil.
4. Water them well after planting so they can settle into their new home!
Pest and Disease Control
You can’t have a beautiful garden without plants, but even your favorite blooms are susceptible to pests and diseases. The iris is one of the most popular perennials in American gardens, but it’s vulnerable to some pretty nasty bugs and bacteria.
Iris borers are a major threat to irises. These pests are the caterpillars of moths. They lay their eggs on the leaves of irises, and when the eggs hatch, the caterpillars burrow into the rhizomes and eat them from the inside out. Once borers have invaded your irises, they’re difficult to get rid of, so try to prevent them from getting in by spraying your plants with insecticide every two weeks and picking off any caterpillars you see.
Irises are also prone to leaf spots. This fungal disease causes purple or brown spots on the leaves of your plant that look like burned paper. If you catch this disease early, you can treat it with fungicide or copper spray; if it’s left untreated, it can spread throughout your garden and destroy everything it touches.
The only way to keep your irises safe is constant vigilance—check your plants regularly for any suspicious pests or diseases so you can stop them before they spread.