Easy Culture Tips for Tall Bearded Iris

From the Brook Lomond Iris Farm

You have just purchased a plant that will provide you with years of gardening joy. Iris fanciers all over the world appreciate the beautiful blooms and hardy growth habit of the tall bearded Iris. The thick fleshy root you have purchased is called a “rhizome.” After the first year Bearded Iris will do fine with little or no care because they are very hardy. After 3 or 4 years the rhizomes should be dug, divided and replanted. Old woody growth should be thrown away. If you avoid overcrowding the rhizome will have room to bloom.

Plant Right Away - Rhizomes have less root growth in early July than later in the shipping season (July, August, and September), but will start to make new roots as soon as planted. Your plants should bloom next spring. Although your bloom should be fairly good the year after planting your best blooms will occur in the second to fourth years.

Where to Plant? Iris prefer a sunny spot with at least one-half day of sunlight. Bearded Iris do not like wet feet so provide soil with good drainage.

Soil - Bearded Iris grow extremely well and can tolerate and thrive in many soil types. Turn your soil to a depth of about 10 inches. Fertilizer and bone meal may be mixed into the soil. A well-prepared bed will result in better growth and more bloom. Clay soils will benefit from the addition of humus, but not sand. Do not mulch with manure, compost or grass clippings.

How Deep? The rule of thumb is to plant higher rather than deeper. Soil should just cover the top of the rhizome and plant should be spaced one- to two-feet apart.

Fertilizer - In Fall use 0-10-10 (1/4 oz. per sq. ft.) or bone meal (1/2 oz. per sq. ft.). In Spring give a side dressing of 5-10-10 before bloomstalks appear. Use granular fertilizer - not liquid and avoid fertilizers high in nitrogen. Water thoroughly at planting and continue to water weekly until plants are established. New leaves will appear and your rhizome will begin to develop. Get ready for a grand show next year!

And Now For the Rest of the Show . . . After three or four years the rhizomes will begin to crowd each other and you should divide the rhizomes and replant. You may dig about two months after the bloom season. Discard the old woody parts and prepare the rhizomes for replanting. This entails cutting both the leaves and roots to about four inches.