Several varieties of Rhododendron catawbiense are other possibilities. Catawba rhododendrons require a protected site and do best in southern and southeast Iowa. The Northern Lights series of azaleas is a group of hybrid azaleas developed and released by the University of Minnesota. Northern Lights' was the initial introduction. Flowers range from light to dark pink.
Flower colors are light pink and deep rose pink, respectively.
Other varieties in this series are 'White Lights,' 'Orchid Lights,' 'Spicy Lights,' and 'Golden Lights' with white, orchid, soft orange, and gold flowers. It has creamy white flowers that are accented by a golden yellow fifth petal. The mollis azaleas also do well in much of Iowa. Flower colors are variable, mainly shades of yellow, orange, and red. The mature height and spread of the mollis azaleas is approximately 6 to 8 feet.