Will a Yucca Produce Multiple Flower Stems?

The Monocarpic Yucca

• A monocarpic plant is one that produces only one flower at the end its often long lifetime. Most agave plants are monocarpic, including the magnificent century plant. Though yucca plants are in the agave family, the only monocarpic yucca is Yucca whipplei "Our Lord's Candle." When the plant is at least five years old a solitary rosette produces a single, self-fertile flowering spike up to 9 feet high. The plant then dies, its reproductive cycle complete.

Polycarpic Yuccas

• Most yuccas are polycarpic plants, flowering several times throughout their lives. Flowering shoots die after blooming and setting seeds, but other shoots continue vegetative production for future growth cycles. Some yuccas produce side shoots at the base called offsets. These offset rosettes become the new flowering portion of the plant when the original rosette dies. Several offsets form a clump, which are divided as a means of propagating new plants. Some yuccas produce tall, often branching, trunks with each terminal rosette producing a flower stalk.

Yucca Pollination

• A very few yuccas, such as Our Lord's Candle, are self-fertile. Other yuccas rely exclusively on the little Yucca moth for pollination. The symbiotic relationship between moth and plant renders them mutually dependent. The female moth lays her eggs deep in a yucca flower's ovary. Collected pollen is then deposited in a ball on the stigma surface. The pollinated flower produces seeds which provide food for the emerging larvae. A single grub is capable of destroying all the seeds in a pod, though consuming only a few. However, enough seeds are produced on a plant to ensure reproduction.

Yucca Varieties

• Hesperaloe parviflora, commonly called "red yucca," is a widely cultivated ornamental in home and commercial xeriscapes. Multiple showy red, coral or pinkish flowering stalks rise 5 feet tall above clumping rosettes of long, narrow leaves throughout the summer. Sun yucca is a yellow flowering variety. Yucca aloifolia "Victor Emanuele II" grows slowly to 10 feet tall and 5 feet wide. Multiple flower spikes 2 feet tall are covered with large, bell-shaped white or purplish flowers. Yucca brevifolia is the desert Joshua Tree. Heavy, branching trunks as high as 30 feet produce foot-long flowering clusters in late winter and spring. Cold-tolerant Yucca filamentosa is commonly called "Adam's Needle." Clumps 5 feet wide display lightly fragrant, cream-colored flowers on stalks as high as 7 feet. "Bright Edge" has yellow-striped leaves; "Color Guard" sports leaves striped cream and white.