For the Spuria Iris Society (SIS)

Welcome to the Spuria Iris Society

Thank you for your membership in the Spuria Iris Society (SIS), a section of the American Iris Society. SIS, organized in 1952, currently:

a. publishes a Newsletter twice a year with articles on hybridizers, culture, information on gardens throughout the country and other items of interest
b. maintains sets of slides available for rental use for local iris groups and garden clubs
c. publishes The Spuria Iris Registrations and Introductions containing detailed information on all registered cultivars of Spuria, their hybridizers, parentages, and awards
d. holds annual meetings each year in conjunction with AIS national convention

Nancy Price, Membership Secretary
32009 S. Ona Way
Molalla, OR 97038
(503) 829-2928
email:

For additional information about our officers, cultural information, awards, iris gallery, and more, please visit our web site at: http://www.spuriairis.com

Spuria Iris Cultural Information

Spuria Iris Culture
by Floyd Wickenkamp
(Reprinted with permission from the Spuria Iris Society Newsletter, Summer 1999)

Spuria irises are classified under the Apogon or beardless subsection of the iris family. The twenty or more species are native to the temperate zone in a band running from Spain and North Africa to India and China. The greatest collection of the species has been found in southern Siberia, always in sunny locations.

The largest concentration of activity in growing and hybridizing spurias is in the sunnier and warmer parts of the U.S., especially California and the Southwest, including Texas and Missouri, and in eastern Australia, but they have also been grown successfully in Montana and Minnesota as well as in northern Europe.

Spurias prefer neutral to slightly alkaline soil and demand plenty of sunshine for good bloom. Even in the Phoenix area they do well in full sun but will also grow and bloom well with at least half day of sun. Spurias are heavy feeders, requiring much more fertilizer than the tall bearded varieties. They also require good drainage and should not be planted where there is likely to be standing water for extended periods. The choice of fertilizer depends on soil characteristics but usually a general purpose fertilizer high in phosphorus will suit. I use 16-16-16 or 16-20-0 and also apply a solution of Miracle Gro or its equivalent in various store brands several times in the fall and early spring. Look for 15-30-15 water soluble powder. I mix one or two tablespoons of the powder in a 1 gallon spraying can and give them a good soaking. If the soil is heavy a liberal application of compost or mulch is desirable.

Most of the commercially-available spurias are summer-dormant, that is they stop growing during the hot weather and will survive with little or no watering, thus minimizing the danger of rot. There are a few varieties that are evergreen (e.g. Belise)–that is they continue to grow during the summer and they should be watered during dry weather.

Spurias generally are free of disease but a fungus that is particularly deadly to the spurias is mustard-seed fungus. Once that gets started in a clump the whole clump is doomed. The fungicide Terraclor is generally used to prevent mustard-seed from getting established. If this fungus is present in your area the best solution is to sprinkle the powder or a water solution to the soil before planting. It is also common practice to dip the rhizome in a Terraclor solution before planting. Commercial growers frequently soak the rhizomes in a 10% solution of sodium hypochlorite (Clorox or equal) followed by dipping in a Terraclor mix of 1 tablespoon to a gallon of water before packaging for shipment.

Spurias generally are among the taller of the irises, averaging perhaps from 3 to 5 feet in height under good growing conditions so they make good background plants. They may be left without separating for several years, resulting in large and very floriferous clumps. In recent years spurias have become popular with florists as substitutes for the bulbous varieties as they are much longer lived than the tall beardeds, for example, in arrangements. Blossoms kept in the refrigerator will often last a week or more so they make desirable corsages.

(The following text (author unknown) is from the Summer 2000 Spuria Society Newsletter, used by permission)

If you can grow bearded irises, you can grow spurias. If a few care guidelines are followed, spuria will reward you with beautiful garden bloom and long lasting cut flowers.

Spurias prefer the same soil as tall bearded iris and they must have good drainage. They prefer full sun and will bloom better if they are not under trees or scribs, even in extremely high temperature areas in the summer. Most of the garden hybrids have a late-summer dormant period. In extreme heat areas, it is best to withdraw water by the 1st of June and let them go totally dormant. If they do go dormant, do not water them. In established clumps, water should be withheld until fall growth begins. Foliage of the dormant types must be cut back to the ground, not only for neatness, but to allow air to reach the rhizomes.

Spurias are very heavy feeders and will reward you with superior plants and flower stalks. Some growers swear by manure, but in hot desert areas, do not use manure. It will cause rot and other fungus to start growing. Besides chances of rot and fungus, manure is high in nitrogen and that will produce the green growth, but not the desired bloom we are trying to get. Use a fertilizer high in phosphate to bring out the bloom. It can be used every two weeks after frost and before bloom starts. If watered and fertilized properly, clumps will persist and bloom for years. It is not unusual to see older clumps spread to 5 or 6 feet across.

Some say it is best to transplant in the fall when new growth is beginning, but others have found digging while dormant does not produce the shock treatment of transplant. Dormant rhizomes will start growing roots and showing new growth within 10 days. In cold climates, their growth gets started and established for the winter if they are planted in July or August. In hot desert climates, plant in October. Be sure to water well when first planted. In the spring water well to push bloom. During dormancy, do not water at all. Once established, spurias are drought resistant.

When spurias are dug to be transplanted, be sure to keep the roots and rhizomes moist. This is very important, as they will not tolerate drying out when out of the ground. They can be packaged with a wet towel or newspaper and placed in a plastic bag and stored in the refrigerator. They can be stored in the refigerator for as long as 3 or 4 months. In fact, this long refrigeration will anhance an early bloom in the spring the first year. Planting depth depends on type of soil. If you have heavy soil you will need to plant at least one inch deep and in light sandy soils plant two inches deep. Space them far enough apart to grow in the same location for years as spuria irises resent being transplanted and usually do not bloom the first year after planting. The second year you will be rewarded with several bloom stalks.