This extremely hardy Yucca is a fairly common sight in select zones. It has very few problems; it requires little maintenance; it tolerates herbivores, drought, poor soils, salt spray, and air pollution extremely well; and its foliage and inflorescences are pleasant sights. Other than a deep tap root and a moderately slow growth rate, Needle palms make an excellent edition through out most of the United States.
Yucca filamentosa (Yucca, Needle palm, Spanish bayonet, Adam’s needle)
Hardiness Zones: 5-10
Height: 1.25-2.5 meters (4-8 feet) tall
Diameter: 1 meter (2-3 foot) spread
Growth Rate: slow, rapid for early summer inflorescences
Age: achieves maximum height anywhere from 10 to 20 years of age
Root System: utilizes a deep taproot to combat drought
Family: Asparagaceae or Agavaceae
Subspecies: ‘Variegata’ (has light yellow stripes on the leaves’ borders), ‘Bright Edge’ (with gold leaf margins), , ‘Color Guard’, ‘Golden Sword’ (gold stripes down the center), ‘Hofer Blue’, ‘Gold Garland’, ‘Ivory’ (cream-colored foliage)
Tolerates: rabbits, deer, drought, heat, soil erosion, dry, shallow, sandy, poor, and rocky soils, urban air conditions, part-shade, salt spray
Problems (major): very few
Problems (minor): virtually none, potentially leaf spot
Poisonous: Found in the roots, saponins are toxic to people. However, they are poorly digested, and the effects may be mitigated.
Soil requirements: dry or moderately moist soils with good drainage, accepts a variety of dry and sandy and loamy soils
Air Requirements: tolerates urban pollution
Watering requirement: low to moderate
Sun requirement: full sun (preferred), part-shade (not recommended)
Primary photosynthetic organ: leaves (all lamina, lacks distinct petioles)
Leaf structure: sharp, up to 3 feet long, basal (form from a central point, forming a rosette)
Leaf shape: sword-shaped or lanceolate
Reproduction by offsets: yes
Monoecious or dioecious: monoecious
Monocot or dicot: monocot
Leaf shape: sword-shaped, sharp-pointed, lanceolate, rigid, basal (originate from one center base),dark-green to bluish (depending on the species)
Leaf size: up to 30 inches long by 4 inches wide, grow up to 1 meter (3 feet) tall in groups formed around a basal rosette
Flower structure: produces white to very light-green, 6 petals total, attractive, bell-shaped flowers on a stalk normally 1.25-2.5 meters (4-8 feet) tall, uncommonly to 3.5 meters (12 feet) tall
Flowering frequency: Flowers in June and July, produces tiny (2-7 centimeters (1-3 inches) in diameter), black, elliptical, disk-shaped fruits in mid to late summer in seed pods resembling unopened peanut pods
Bulb/tuber: neither, consists of a taproot system
The stem is miniscule compared to the rest of the plant. The sword-shaped leaves have parallel veins, pointed ends, and thin threads (called “filaments”) alongside the leaves’ margins. The inflorescence consists of a tall flowering spike with dozens of white, bell-shaped flowers. These reproduce by seeds and vegetatively by producing offsets/offshoots and cuttings. Since not all of the root system is typically removed, new plants often emerge where others were extracted. Y. filamentosa is monoecious (the flowers are “perfect”, having both male and female reproductive organs). The seeds presumably require 2 years to germinate. These are very easy to grow if given full sunlight and occasional watering.
Popularly grown as an ornamental in most of the United States. These are typically good, low-maintenance garden plants.
A fairly mature plant with an inflorescence flowering spike, foliage, and opened seed pods
A close-up of the foliage and filaments
The images provided were taken by me during 2013 and 2014. They may be used for informational and/or educational purposes provided that this online journal or article is appropriately cited/referenced first.