Iris Cristata is a popular plant in the woodlands

Iris Cristata Plant Description

Growing in the Central Southern US states to the Central Mississippi Valley is the beautiful Iris Cristata, a species in the Iris genus. The Iris plant grows naturally in calcareous soils, rich woody slopes, and plain swamp forests in the flecked shade. Its flowers differ from purple, lavender-blue, to white and are perfect for landscaping underneath trees, such as the red maple tree. To learn more about the American native iris, we provide a detailed description, recommendations for planting underneath trees, and care.

Characteristics of the Iris Cristata

Known as a native, crested iris, Wikipedia describes Iris Cristata as a shallow-rooted plant growing low to the ground, approximately three to six inches tall. A favorable plant feature is it rapidly spreads when appropriately planted and maintained. For example, planting the crested iris is preferable during the spring or early summer for flowers to bloom underneath a maple tree. Next is a detailed description of the crested iris plant.

Description of the Iris Cristata Plant

Lavender, purplish, blue, or white petals with gold crests on the sepals.

Broad arching leaves arise from shallowly rooted, spreading, slender, greenish, or whitish-yellow rhizomes.

Underneath the rhizomes are tissue-like roots.

Two to eight corded, brown branches ranging from eight to 12 inches long and one to two millimeters.

Six to eight basal leaves are divided into two to three proximal leaves and four to five distal leaves.

Three- to six-inch leaves.

One-inch to two-inch stems with two to three cauline and spates, the green leaves of the flower bud that bear one-inch to two-inch flowers in April to May.
Recommendations for Planting Crested Iris Under a Maple Tree


Understanding how to plant Iris Cristata underneath trees requires knowing which trees are adaptable without damaging their roots. The maple tree is a dense-canopied tree that thrives in moist soils, creating massive shade for Iris Cristata to grow and rapidly spread. Before planting, avoid cutting the roots or deep digging, but add soil around the tree instead, approximately two to four inches of the bottom base.

To ensure the soil receives proper treatment, add wood chippings or shredded bark until decomposed for organic matter to maintain moisture. Another option for protecting the roots of a maple tree before planting the Iris Cristata is to apply light-blended soil over the area. When cultivating the crested iris without adding soil, dig no more than two-inch holes without disturbing existing roots.

Caring for Crested Iris Plants

Water regularly for two months until the plants develop. Soak the entire ground plant area to encourage root growth. Avoid watering the lower trunk of the maple tree near the base.

Allow the soil to dry completely between each irrigation treatment to improve the soil structure.


Iris Cristata is a popular plant in the woodlands, rich woody slopes, and floodplain forests in the United States. While the white flower crested irises are rare in some regions, the violet, blue, and lavender flowers are favorites to complement tree landscaping. Remember that watering the plants regularly and carefully improves the structure and growth of crested irises underneath maple trees and other dense-canopied trees.