Culture

Growing Tips

When To
Plant:
For best results, plant from June through September. Early planting establishes the new iris before winter. This is also the time to divide clumps of iris that are overcrowded, generally clumps that are 3 to 4 years old.
Where To
Plant:
The ideal location for iris is a sunny, well-drained area. Sun should be present for at least 6 hours. Iris do not do well in deep shade. Iris will not tolerate wet feet. No water should stand in the iris beds. Raise the beds slightly above the level of the garden paths, if necessary.
Planting
Depth:
The iris leaves should be trimmed 6 to 8 inches in a fan shape, prior to planting. Plant rhizomes just below the surface of the ground. In fact, it is okay for the top of the rhizome to show above the surface of the earth. Spread the roots out well underneath by making a small mound of earth in the center of the hole and spreading the roots out and down. The nose of the iris should face the sun. The rhizome is then within reach of the sun’s rays, while the roots beneath the soil are in moist soil. Water the soil gently to settle in the new plant.
Distance
Between
Plants:
Generally, iris are planted from 14 to 18″ apart. If you want an immediate clump effect, you can plant the iris 8″ apart in groups of 3 or more of one variety. You may have to divide your plantings more often, but you will have a wonderful splash of color sooner than if you planted only one rhizome of one variety.
Fertilizing:

In order to bloom and grow well, irises require a moderate amount of fertilizer. Feed your irises in the spring as soon as the soil is workable and new growth begins. Use a general purpose flower or vegetable garden fertilizer containing ” slow release nitrogen”*. Never apply more fertilizer than the manufacturer recommends, and keep the granules at least six inches away from the fans. When planting a new rhizome, work up a volume of soil about the size of a bushel basket and thoroughly mix in compost, a teaspoon of triple phosphate, and a tablespoon of fertilizer before planting.

* also called timed release, continuous release, or extended release

Cultivating: Do it shallowly. Iris feeding roots are very near the surface. Keep you iris free of weeds and do not allow neighboring plants to encroach upon them. Remember, they need sunlight down to the rhizome. Keep grass, weeds, etc. away from the rhizomes. Brown leaves can be trimmed off at any time. Clean cultivation is the finest precaution for iris.