Planting Iris bulbs (or rhizomes) in your garden can start off the growing season with a burst of color!
While it's true that most folks refer to Iris bulbs, Iris are actually grown from rhizomes.
A rhizome is a particular type of bulb that is a thickened stem filled with nutrients which support the growing Iris.
Typically, these bulb types grow horizontally and spread outwards either partly or completely below the soil surface.
Planting Iris Bulbs
The growing point is mainly at the tip of rhizome. Other buds are formed along the upper surface and along the sides of the rhizome.
The roots of the rhizome develop from buds on the underside of the bulb.
Remember in your planning that you will be planting iris bulbs in late summer for blooms to show the next spring.
It is best to plant Iris so that roots are spread out facing downward in the soil and the tops of the rhizomes are exposed to the sunlight.
Try to resist the urge to plant the Iris bulb into the ground; you want to keep the top of the rhizome at the soil surface.
If you live in an extremely hot climate, cover the rhizome with about an inch of soil to keep the rhizome from become too dry.
After firming the soil around each rhizome, water the area to help settle the soil and help the root system become established.
A good rule of thumb to remember when gardening Iris bulbs is to plant them 12-24in apart.
Planting your rhizomes closer than 12-24in apart will give you a full effect immediately; however it will also cause you to need to thin the clumps more often.
Using the 12-24in distance when planting iris bulbs you'll find you'll need less frequent thinning of your plants.
Once established, Iris normally don't need to be watered except in dry, arid climates.
As with resisting the urge to plant your Iris too deep, resist the urge to overwater your Iris also.
If you are in the dry, arid climates, deep watering an area at long intervals is better than frequent shallow waterings.
For more detailed information on these flowers, check out the American Iris Society website.