Horticulture Unlimited Inc.

Plant Guide

Organ Pipe Cactus
Organ Pipe Cactus

Stenocereus thurberi

This distinctive night-blooming cactus grows in a columnar, tree-like form to twenty feet tall or more, producing multiple stems that form clumps. Mature plants will reach twelve to fifteen feet wide with many branches.…

Palma China, St. Peter’s Palm
Palma China, St. Peter’s Palm

Yucca filifera

The dramatic, fast-growing landscape specimen with a massive base towers to heights of fifteen to twenty feet. It has sharp, pointed, short, rigid leaves that are dark to olive green with filaments growing along the marg…

Palmer’s Agave
Palmer’s Agave

Agave palmeri

The plant is recognized by its banana-like fruit and dramatic flower stalks that reach ten to fifteen feet, producing a panicle of blooms in green and pale pink. It grows to four feet tall and four to five feet wide, for…

Palo Brea Tree
Palo Brea Tree

Parkinsonia praecox

Sometimes called Sonoran palo verde, the palo brea tree has a wide, open and spreading crown, making it a favorite shade tree in Tucson and Southern Arizona. This drought-tolerant, native tree is perfect for xeriscapes a…

Parry’s Agave
Parry’s Agave

Agave parryi

Native to Arizona, New Mexico and northern Mexico, Parry’s agave produces larger leaves and rosettes than many of its sub-species. It consists of compact, nearly round rosettes of gray-green leaves that grow 7-20 inches…

Partridge Breast Aloe
Partridge Breast Aloe

Aloe variegata

This dwarf aloe with spotted white and green leaves resembles the breast of a partridge, as its common name implies. It grows in a clump and stays low to the ground, usually below one foot tall. It is one of the most dis…

Passion Flower
Passion Flower

Passiflora foetida

The deciduous, fast-growing, creeping vine climbs twelve to fifteen feet with tendrils and thin stems that are covered with sticky, yellow hair. Its dark green foliage has three- to five-lobed leaves and produces an unpl…

Pencil Milk Bush
Pencil Milk Bush

Euphorbia mauritanica

The pencil milk bush is a pencil-like, branching plant with upright, bright green, cylindrical stems that sprout in the shape of a small shrub. Its small leaves will grow along the grayish green stem. The clumping, low-g…

Pendulous Yucca
Pendulous Yucca

Yucca recurvifolia

This single-stem or sometimes multiple-stem plant grows to six feet and is recognized by bluish-green, pendulous leaves that have a sharp point at the tip. There are also beautiful, variegated forms available. In late sp…

Periwinkle
Periwinkle

Vinca major

The low-growing evergreen spreads and roots along the ground with its trailing, arching stems, forming a dense mat. It has dark glossy green, slightly hairy foliage with pointed tips. In early spring, it produces purplis…

Peruvian Apple
Peruvian Apple

Cereus peruvianus f. monstrose

The cactus is admired for its knobby branches, flowers that open at night and red, apple-like fruit. It is a moderate grower, reaching heights of ten to twenty feet with a spread of fifteen feet or more. However, the var…

Peruvian Verbena
Peruvian Verbena

Glandularia peruviana

The fast-growing groundcover with its colorful flowers reaches six inches or taller, with a three- to six-foot spread. It trails and spreads along the ground, producing new herbaceous roots as it grows to form a dense ma…

Plumbago
Plumbago

Plumbago auriculata

The evergreen is admired for its brilliant sky blue flowers with a loose, sprawling growth habit and grows four to six feet tall and four to ten feet wide. It has arching branches, long, skinny stems, and thin, green fol…

Pomegranate
Pomegranate

Punica granatum

Pomegranate is a fast-growing, deciduous plant noted for its berrylike fruit that grows six to fifteen feet tall with a multiple or single trunk. ‘Nana’ is the dwarf variety and it reaches just one to three feet. The spe…

Ponytail Palm
Ponytail Palm

Beaucarnea recurvata

Ponytail palm is a grass-like evergreen with a large, bulbous base, long, swollen trunk, and palm-like features. It grows to heights of thirty feet or more and twelve feet wide. With age, the trunk may develop a few bran…

Prostrate Myoporum
Prostrate Myoporum

Myoporum parvifolium

Prostrate myoporum has grass green, narrow leaves evenly spaced in spirals around horizontally spreading stems. It is commonly used as a ground cover. A profusion of small white flowers appear in the spring and continue…

Purple Coral Pea
Purple Coral Pea

Hardenbergia violacea

The twining, woody evergreen climbs slowly to ten to twelve feet tall and about five feet wide with long, grayish-green, leathery leaves with prominent veins. In early spring, the vine produces showy clusters of lavender…

Purple Heart
Purple Heart

Tradescantia pallida

This attractive perennial is noted for its violet purple leaves and low-growing habit to one foot with an almost equal spread. The undersides of its narrow, oblong leaves are deep violet to pink. The plant is a vigorous…

Purple Leaf Plum
Purple Leaf Plum

Prunus cerasifera

The attractive, deciduous tree has an upright, spreading habit with a rounded crown, and is a moderate- to fast-grower reaching fifteen to twenty-five feet tall and about fifteen to twenty feet wide. In spring, beautiful…

Purple Prickly Pear
Purple Prickly Pear

Opuntia santa-rita

Native to the Sonoran desert, the purple prickly pear grows in clumps, usually to about 4 feet tall by 5 feet wide. This cactus appears much like a shrub. The large leaf pads develop a purple tinge in the cool, dry winte…