Iris span a huge range of colorful varieties, among which bulbous Iris hollandica, or Dutch Iris also known as The Goddess of the Rainbow, are the most popular in the U.S. Hybridized in the early 1900s from Iris xiphium, a 16th century Spanish native, these deer-proof, light, airy flowers create magical displays in late spring gardens and in classic bouquets. The standards are the inner, upright petals. The falls are the outer petals that open downward to reveal a contrasting color on the petals' spines. Bulb size: 8 cm/up. Plant in full sun. May/June. Plant 6" deep and 6" apart. HZ: 5-8. 18" to 22".