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    Bearded Iris

WHEN TO PLANT: For best results, plant from July through September. Early planting establishes the new rhizomes before winter. If you live in an area with a strong winter climate, plant at least 4-6 weeks before a hard frost. July through September is also a good time to dig and reset clumps of iris that are crowded, usually after 3-4 years growth. If you live in an area with a harsh winter climate, your iris may require some sort of winter protection, especially the first year. Check with your local county agricultural agent to see what they recommend.

WHERE TO PLANT: The ideal location is a sunny, WELL-DRAINED position. Sunshine should be at least a half-day. Iris will grow in deep shade, but will not flower. Water should not stand in your beds; raise beds slightly above the level of the garden paths if necessary.  Good air circulation is essential.  Without it, foliage diseases and rhizome rots thrive.

SOIL PREPARATION: This is the most important factor in growing iris. Work the soil well to a depth of 10 to 12 inches. If your soil is heavy, incorporate sand or some other material that will allow moisture to percolate out quickly. Addition of compost or other organic material will greatly benefit the soil and produce better plants. Gypsum is also an excellent soil conditioner. Have your soil tested before applying any other corrective measure. We recommend addition of alfalfa pellets to amend the soil.

DEPTH TO PLANT: Place your rhizomes at or just barely below the surface of the ground with the roots spread well out underneath so the rhizome is within reach of the sun's rays while the roots beneath are in a moist (not soggy) soil. DO NOT PLANT TOO DEEPLY! Be sure to firm the soil tightly around each rhizome when planting. At times of excessive heat, newly set plants can be shaded by an upright shingle or some such protection, cutting off the direct rays of the sun for a few days.

Step (1) Build up a small mound of soil in the center of the planting hole.  
Step (2) Center the rhizome on the soil mound and spread out the roots on either side.
Step (3) Firm the soil around the roots.  Newly planted rhizomes should be watered thoroughly. 
Be Patient -- Irises are perennials and require time to grow.  New growth may not be noticed until late Fall or in the Spring the next year.  There may not be blooms until yet the next Spring after initial planting.

Figure 1.  Build up a small mound of soil in the center of the planting hole.

Figure 2.  Center the rhizome on the soil mound and spread out the roots on either side.

Figure 3.  Firm the soil around the roots.  Newly planted rhizomes should be watered thoroughly.

DISTANCE APART: This depends on your particular plans. Generally iris are planted 12 to 24 inches apart. Closer plantings will give an immediate effect, but will need thinning much sooner. To give an immediate clump effect, plant three rhizomes of one variety in a triangle with the toes of the rhizomes pointing inwards about 8 inches apart.

WATERING: Again, this depends on your location. Newly set plants need moisture so they can grow a new root system. Keep newly planted rhizomes moist, but not wet, until strong growth is apparent. They appreciate the attention. Water at fairly long intervals in dry weather. Established plants do not require watering except in very arid parts of the country. The common mistake is to give iris too much water! FERTILIZING: Iris will thrive without feeding but will respond to fertilization with spectacular results. An application of a well-balanced fertilizer (5-10-5), applied as a top dressing dusted around and in between plants in the early Spring and very late Fall is desirable. Fertilizer can also be applied right after bloom is finished. Any fertilizer application should be light. In general, fertilizers high in nitrogen, including fresh manure, should be avoided because too much nitrogen encourages rot problems.

Bone Meal as a slow release phosphate source is recommended to be applied at planting time.  Triple phosphate is more rapid than Bone Meal and may "burn" rhizomes if too much is used at plating time and/or if the rhizome is in direct contact with this fertilizer.  

Also, when applying a Herbicide such as Weed and Feed to an adjacent lawn with a spreader which might cast onto the iris should be avoided.  These chemicals may cause much harm to your iris plants.    

BLOOM SEASON: Variety of iris will determine the height of the bloom stalk (stem) and bloom time. Median Bearded Irises, such as standard dwarfs, bloom as early as late March. Tall Bearded Iris may bloom as late as June. SDBs range in height from 8 to 15 inches, where as the TBs range from 28 to over 40 inches. After the bloom is complete, cut the bloom stalk as close to the bottom as possible. Seedpods may appear as a result of hybridization. If is best to cut these away from the plant. During the rest of the year, established irises require little care except for attention to the signs of disease and the few iris pests. Keeping the iris beds CLEAN (free of fallen leaves and weeds) is very important. Irises suffer less from diseases and pests than most other garden plants under normal conditions.

GENERAL GARDEN CARE: Remove limp outside foliage as the iris grows, otherwise do not trim iris foliage if green. Brown or diseased leaves should be cut off and removed from the garden. At all times, try to keep all garden litter, grasses, etc. away from the rhizome. Bloom stalks (not leaves!) should be cut off close to the ground after blooming. It is especially important to keep the garden clean during winter and not allow dead leaves, etc. to remain around the plants.

An iris garden should not be over watered, or overfed. This is an example of fungal leaf spot. It is a major disease of iris foliage. Note the brown rims that ring the lesions. Keep an eye out for the onset of leaf spot (bacterial or fungal which look similar) during wet weather. Once present, bacteria spot can be treated by cutting the infected foliage away and removing it from the garden. Fungal spot can be treated with fungicides with moderate effectiveness. If leaf spot is a problem, soak in fungicide for 30 minutes after rinsing in bleach water. Dust any open wounds with sulfur. The best cure is prevention by not over watering.  

Another major problem is Soft Bacterial Rot that again can be caused by over watering. Symptoms of Soft Rot include very smelly, soft, and mushy rhizomes. When this disease is present, the rhizome should be dug, the infected tissue scraped away, treated with 10% bleached, and dried well before replanting into another healthy area. These are the two most frequently encountered problems.

Figure 1.  Digging a three year iris clump.

Figure 2.  Remove excess dirt and discard the old center divisions.

Figure 3.  Separate the individual rhizomes for replanting.

MOVING OR THINNING YOUR IRIS: Every 3 or 4 years, dig clumps, remove and discard the old center divisions that have bloomed and replant the new large fans with strong foliage. Use a sharp knife to separate rhizomes, borer holes or diseased looking parts. Trim leaves halfway back to an inverted V shape (^) and also trim roots back to about 4-6 inches. Soak for 1-10 minutes in 10% bleach solution, dry in cool, shady place for a day. If leaf spot is a problem, soak in fungicide for 30 minutes after rinsing in bleach water. Dust any open wounds with sulfur.

This is Mr. Safford - George's Friend. He is tilling his ground to plant iris later this year.  More experienced irisarians have tried other methods for starting bearded iris in pots.  Thanks to Glenn Simmons in Springfield, Missouri for the contact.  And thanks to Walter Moores with the North Mississippi Lakes Iris Society in northern Mississippi for sharing his experience with us.