Oh, Yucca! Do you picture this plant as a pokey, static, and rather dull component of a landscape?Au contraire! We posit the yucca as a plant of majesty, elegance, and fascinating complexity. Not to mention an easy evergreen keeper in the garden.
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| Native yuccas have architectural interest after flowering |
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| Yucca glauca, in New Mexico the bright mass of flowers gives it the name Lamparas de Dios, which translates as Lamps of the Lord. Note downward orientation of flowers. |
The yucca is a tough customer alright, with leaves adapted to withstand drought and cold, and pointy, sometimes sharp tips. In contrast to its rugged exterior though, its blooms are extravagantly luxurious; bell-shaped, fragrant flowers enclosing a mysterious relationship and performing gymnastics to become holders of seeds.
The mystery is not so hard to explain, co-evolution over thousands of years between the yucca and the yucca moth. What’s mysterious is the exclusivity and the complexity of their relationship. There are dozens of species of yucca, but with the exception of one, Yucca aloifolia, every one of them must do a dance of partnership with a specific moth in the Tegeticula or Parategeticula genus, known as yucca moths. These two living beings depend upon each other for their existence, one cannot procreate without the other, and they have established a partnership that benefits each of them in multiple ways.
Poor little yucca moth - unlike most moths and butterflies it lacks a long tongue. Well, that doesn’t matter too much because the adult moth isn’t around long enough to need to eat anyway. It’s meet, mate, and move on, all on, in, or under a yucca plant. After the meeting and mating, the female moth uses her short life to accomplish some tricky feats. The moths have emerged just as their yucca has come into bloom. The female must use special tentacles around her mouth to scrape pollen off several anthers (male part) of a yucca flower. Then, carefully protecting the resulting lump of pollen under her chin, she takes wing for an inspection tour.
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| Yucca flowers progress from upward facing to downward |
Leaving the pollen source plant, she seeks out a new yucca at the right stage of flowering, (yay, cross pollination!). Now her inspection tour goes deep. Into the flower’s ovary she descends, making sure that no other moth eggs are already occupying the space; her antennae signal the scent of another female’s presence. This works for everyone - an overburdened flower would abort, depriving both the plant and the moth babes of a future. Now the yucca moth mama opens a small hole in the flower's ovary, deposits her eggs inside, and finally, she makes her way to the stigma (female part) of the flower, where she scrapes off some of her pollen. Perfect! Now the flower is fertilized. There will be a fruit. The moth larvae will have seeds to eat, but will leave plenty behind. Both flower and moth will continue on to the next go-round of the amazing, and often unseen web of life on earth.
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| By late fall, seed capsules split open and release hundreds of flat black seeds. The capsules often persist till spring or beyond as these have. |
Yuccas have have made adaptations to a range of habitats from deserts to grassland, mountains and coastal scrub. From New Jersey down to Florida and across the Midwest, you can grow the native Yucca filamentosa among others. In the West, Yucca glauca is common, but you have many others to choose from there as well. Only the northernmost states on both coasts, where there is too much moisture, lack native yuccas.
Yuccas make excellent accent plants or focal points in a garden. Plant them where they will have space to spread as they mature, and not near walkways, of course. They remain green all year, even in the snow or the deepest heat of summer, and require a minimum of water, making them perfect candidates for low-impact gardening.
After you have selected the species that grows in your region, and brought the plant home, make sure to dig a hole wider and deeper than the container. Yuccas have deep taproots which you need to keep protected, these taproots also mean the plant will prefer not to be moved once settled in. You must water new plants until they establish, but keep in mind that the yucca's natural adaptation to drought and dry conditions means that over-watering will not be welcomed.
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| Yucca filamentosa in garden at end of winter in Riverbend Park, VA. The tough white filaments of the yucca had many uses in the past, forming nets, sandals, and baskets, |
There is no doubt that yuccas make dramatic ornamental statements. In fact, one yucca has its own national park in California, Joshua Tree National Park. The famous Joshua Tree is actually Yucca brevifolia!
In addition to the yucca moth, various yuccas provide food for several skipper caterpillars as well as food, roosting and nesting sites for birds, small mammals and reptiles.
Natives give life!
In addition to the yucca moth, various yuccas provide food for several skipper caterpillars as well as food, roosting and nesting sites for birds, small mammals and reptiles.
Natives give life!
