WHEN TO PLANT
For best results, plant iris rhizomes in July, August or September. The roots of newly planted irises must be well established before the end of the growing season. In areas with mild winters and hot summers, irises may be planted in September or October.

WHERE TO PLANT
Irises require at least a half-day of sun. Some shade is beneficial in extremely hot climates, but in general irises do best in full sun. Provide your irises with good drainage by planting on a slope or in raised beds.

SOIL PREPARATION
Irises will thrive in most well drained soils. If your soil is heavy, coarse sand and humus may be added to improve drainage. Gypsum is an excellent soil conditioner that can improve most clay soils. The ideal pH for irises is 6.8 (slightly acidic) but irises are quite tolerant of less-than-perfect soils. Have your soil tested before making corrections. Lime may be added to acidic soils and sulfur may be added to alkaline soils.

DEPTH OF PLANTING
Irises should be planted so the tops of the rhizomes are visible. Spread roots beneath and tamp soil firmly to anchor the rhizomes until new roots begin to grow. Water well at planting time. In extremely hot climates or with very light soils, cover rhizomes with one inch of soil. IT IS A COMMON MISTAKE TO PLANT IRISES TOO DEEPLY.

SPACING PLANTS
Planting rhizomes 12 to 24 inches apart is the norm. Close planting results in instant color but makes dividing clumps a necessity in 2 to 3 years.

WATERING
Newly planted rhizomes need moisture so their root systems develop. Once established, irises usually do not need watering except in arid regions. Deep watering on occasion is better than frequent shallow watering. OVER WATERING OF IRISES IS A COMMON MISTAKE.

FERTILIZATION
Soil type for your area will determine your fertilizer needs. Superphosphate, alfalfa pellets (without salt), bone meal or 6-10-10 fertilizer are recommended. Avoid anything high in nitrogen as it encourages soft rot. A light application in early spring and again a month after bloom is appreciated. Place fertilizer around rhizomes, not directly on them.

DIVIDING CLUMPS
When irises become crowded, usually every 3 to 4 years, bloom will decline. At this time, old clumps may be thinned by removing several divisions and leaving a portion of the clump in the ground. A better practice is to remove the entire clump, replenish the soil and replant a few large rhizomes.

GENERAL GARDEN CARE
It is extremely important to keep your iris beds free of weeds and fallen leaves so the rhizomes may bask in the sun. Spacing plants so there is good air circulation will help prevent diseases. Break out bloomstalks as soon as bloom season is over. This prevents contamination of your named varieties by chance bee crosses. These crosses would cause seedpods to form that might go unnoticed. If given time to ripen, they might drop seeds to the ground. The resulting new plants are often unattractive. So breaking out bloomstalks right away is a good garden practice.

BEARDED IRIS TYPES
By all means grow all sizes of bearded irises.

MDB – The tiny Miniature Dwarf Bearded (MDB) irises bloom early and grow up to 8 inches in height.

SDB – Next to bloom are the small Standard Dwarf Bearded (SDB) irises that grow from just over 8" to about 15 inches.

IB – Intermediate Bearded (IB) irises bloom next and are in the 16 to 27 inch height range.

Next, there are three bearded iris classes that bloom at generally the same time. They are Miniature Tall Bearded (MTB) irises, Border Bearded (BB) irises and Tall Bearded (TB) irises.

MTB – are in the neighborhood of 16 to 27 inches tall with flexuous stems and small flowers.

BB – are also 16 to 27 inches with smaller than TB-sized flowers to fit their shorter stalks.

TB – are over 27 inches tall with larger flowers and are by far the most widely grown and admired. Quite a few iris varieties bloom again in the fall. A list of those varieties that rebloom in various parts of the country on a regular basis may be obtained through the American Iris Society.