Rather large selections of iris flower rhizomes have been available for many years due to the efforts of several large nurseries that specialize almost exclusively in German bearded iris.
Most of us know that the iris is one of the most dependable and abundant blossom producers that we as gardeners can plant.
How hardy is the German bearded iris?
I have always said that you can dig up your iris on the warmest of summer days, throw the rhizomes out on top of the sidewalk, let them sizzle there for a month and you could then plant them and they would thrive.
Yes this is far from being truthful but I have known of gardeners that allowed their plants to lie around without special care for extended periods of time and when finally planted have done very well.
However, if we want this beautiful perennial to reward us with abundant color, then we should at least consider the following:
The first step is to always have your soil tested by a private laboratory.
Be sure to inform them of your intentions to grow iris so they will be able to prescribe the steps and products required to arrive at the correct ph and nutrient levels. An excellent ph range is 6.5 to 6.8.
Avoid high nitrogen fertilizers as rot may develop.
Provide a sunny location with the benefit of at least six hours of sun daily.
A good loose soil is necessary for good results. Compacted or tight soils should be improved with the addition of six inches or more of compost and then worked into the top eight to ten inches of garden soil.
We do not suggest the use of sand as a soil conditioner for tight or clay soils as it is too easy to turn the soil in the bed into concrete.
Iris flower rhizomes need shallow planting with the rhizome tops being no deeper than soil level.
Space your plants about eighteen inches apart with the tip of all the rhizomes pointing in the same direction so as they develop new plants they will not tend to crowd each other out.
Water thoroughly after transplanting and continue to apply moisture until they are established. You will know when they are established as new top growth will be visible.
When dividing your own stock simply dig up the clumps and clip off the rhizomes being sure that each division has adequate roots. Keep the original plant if so desired as it will produce additional starts but will not flower as each rhizome will reward us with flowers only once.
Iris should be divided every three to four years.
Good luck in growing iris and most of all have fun and reap the benefits of exercise.
