Spring blooms in the Sedona-Verde Valley

By Beverly Lehnhardt

Sedona, AZ - Spring in the Verde Valley brings a plethora of brightly colored blooms emanating from a multitude of plants. Many of the plants are cacti that enjoy the cold nights and warm, sunny days.

The yucca is one type of cactus that blooms in the spring, adding its creamy-white blooms to the abundance of color.

Although there are over 40 types of yucca, the two most commonly seen in yards in the Verde Valley are the Thompson Yucca (Yucca Thompsoniana) and the Banana Yucca (Yucca Baccata).

Thompson Yucca

Another type, the Soaptree Yucca (Yucca Elata), is indigenous to the Southwest, including the Sonoran, and Chihuahuan deserts, and is often seen dotting the desert landscape.

The short, stiff, semi-succulent leaves of the Thompson Yucca form compact green rosettes. Many plants develop a wooden trunk that can branch and become tree-like, growing multiple �heads� of the stiff-leaved rosettes and typically reaching a height of 15 feet. They are very hardy, tolerating a wide range of soil and temperature conditions, preferring full sun and good drainage. They require little additional watering and transplant easily�very good qualifications for landscape plants.

In spring, the Thompson Yucca sends up a thick shoot containing numerous white to creamy-white blossoms clustered together on the upper section of the stalk. This flowering stalk is usually not much taller than the tops of the stiff leaves but is covered with beautiful blooms. Unlike its cousin, the agave, the branch or plant that produces the flower does not die after blooming. The yucca is �dioecious��the male and female flowers appear on separate plants.

Soaptree Yucca

Interestingly, the flowers of the yucca must be pollinated by a very specific insect, the yucca moth, in order to bear fruit. Only the female of the species is adapted for this task. Once the female yucca moth is pregnant, she uses a pair of long, curved, prehensile appendages in the mouth region (called maxillary palpi) to collect, form and carry a golden mass of pollen called a pollen ball. Male yucca moths and most other moth species do not have these specially adapted appendages.

At this point, ready to lay her eggs, the female crawls into a yucca flower on a plant other than the one from which she collected the pollen and carefully positions herself. Using her egg-laying device, an ovipositor, she inserts a single, slender egg into the �ovule chamber,� an area where the ovary wall is thinnest. Now ready for pollination�the crucial event that enables the perpetuation of all yuccas in the wild�she climbs to the top of the ovary, still carrying the pollen ball. At the top, she uncoils her palpi and presses the pollen into the central depression. This act ensures pollination of the flower in which she deposited her egg. Germinating pollen grains send hundreds of sperm-bearing pollen tubes into the ovary, resulting in the fertilization of many immature seeds, some of which provide food for the hungry moth larva.

Banana Yucca

Although the yucca moth larva hatches inside the developing seed capsule of the flower and feeds on the maturing seeds, only a small percentage of the seeds are consumed. The seed capsule contains three sections, each with two columns of up to 38 flat, black seeds. In late fall, these seed capsules rupture, releasing their seeds. The moth larva remains inside its feeding cavity of fused seeds until the first autumn rains when it emerges and drops to the ground. It then burrows into the soil and constructs a cocoon where it remains for the winter. Spring rains and warmer temperatures stimulate the formation of the pupa and the emergence of an adult moth. It is imperative that adult moths emerge when yucca plants are once again in bloom so that the cycle between moth and plant can be maintained.

The Banana Yucca�s leaves are more blue-green than green and the plant has a short or non-existent trunk. It begins flowering in April and the blooms are white to creamy-white with purple shades; the flower stalk is thick, but not much taller than the tops of the leaves.

The springtime flowers are said to be delicious and the summertime fruit is an edible, fleshy green capsule (resembling a pickle more than a banana) up to 5 inches long with many tiny seeds. The Native American Paiutes dried the fruit for use during the winter. The leaves were used to make paintbrushes and cordage while leaf fibers were woven into rope, string, cloth, bowstrings, nets and thread.

Like the Thompson, the Banana Yucca is dioecious and is pollinated only by the yucca moth.

Soaptree Yucca

The Soaptree is one of the largest members of the yucca family. Its 2-foot long, thin, flexible, sharp-tipped leaves grow from a central cluster forming a rosette. This leaf arrangement collects the Southwest�s scarce rainwater and channels it to the plant�s center. The Soaptree has a 6- to 12-inch diameter, grayish-colored trunk that supports the large rosette of leaves and can exceed a height of 20 feet. The leathery leaves have fine white, curly threads growing along the edges.

Between May and July, a tall spire grows from the center of the rosette and sprouts clusters of 2-inch, bell-shaped, white flowers along the top 1/3 of the stalk. This spire can reach 30 feet in height, towering high above the tops of the leaves. The Soaptree Yucca is also dioecious and is pollinated by the yucca moth.

The roots of the Soaptree are known as amole and are used as a soap substitute, giving the plant its name. The Native Americans weaved baskets, mats, cloth, rope, and sandals from the course fiber of the leaves. Chopped trunks and leaves are utilized as emergency cattle feed during times of drought.

The Thompson, the Banana, and the Soaptree Yucca all require very little maintenance. Flower stalks may be removed and any old, yellow leaves can be plucked. When planting, bear in mind that groupings will result in a collection of wind-deposited debris since it is difficult to get in between plants to clean up or remove old leaves and stalks, but singly, any of these yucca plants would be attractive additions to your yard.

[Home Page] [News Home Page] [Back to Community Page]

about us | privacy policy | advertise | bookmark this site