Horticulture Unlimited Inc.

Plant Guide

Queen Victoria Agave
Queen Victoria Agave

Agave victoriae-reginae

This rare, striking agave, named for Queen Victoria in England, forms a small, symmetrical, rosette of dark green foliage with white markings on the side of its toothless leaves. A sharp spine is apparent on the end of e…

Queen’s Wreath
Queen’s Wreath

Antigonon leptopus

<div class="fancybox-outer"> <div class="fancybox-inner"> <div id="popup-687"> <div> <div class="description">The fast-growing, tender perennial climbs thirty to forty feet tall with curled tendrils and bright green, hea…

Rabo de Leon, Hedgehog Agave
Rabo de Leon, Hedgehog Agave

Agave stricta

The Mexican native agave grows two to three feet tall and wide, creating a spherical rosette of elongated, dark greenish-yellow, lightly serrated, and lightly curved leaves. The pencil-like leaves are thicker at the base…

Rattlesnake Agave
Rattlesnake Agave

Manfreda maculosa

The dramatic succulent grows to eighteen inches tall and one to two feet wide to form a tight, clumping rosette of fleshy, sword-shaped, smooth-textured leaves. The foliage is green and mottled with purplish-red, irregul…

Red Bird of Paradise
Red Bird of Paradise

Caesalpinia pulcherrima

The Red Bird of Paradise <em>(Caesalpinia pulcherrima)</em> has long been a favorite summer blooming plant in Tucson, Arizona. It celebrates the warm season with a dazzling display of orange-red flowers. This shrub grows…

Red Yucca, Yellow Yucca
Red Yucca, Yellow Yucca

Hesperaloe parviflora

The medium-sized, evergreen produces stiff, dense clumps of leathery, gray-green leaves that when blooming, grow three feet high and wide in a tight rosette. Its upright growth habit has arching foliage that forms a dens…

Resin Spurge
Resin Spurge

Euphorbia resinifera

This low-growing succulent has erect, thick, bluish-green to lime green, four-sided stems with small brown thorns, reaching one to two feet with a three- to four-foot spread. Historically, it is one of the oldest documen…

Rosemary
Rosemary

Rosmarinus officinalis

Rosemary is a hardy evergreen with needle-like, deep green, fragrant foliage that grows three to five feet high and three to eight feet wide. It is popularized as a landscape plant and offers edible leaves that when drie…

Saguaro Cactus
Saguaro Cactus

Carnegiea gigantea

This giant monarch cactus grows to fifty feet or more with a large spread, depending on how many arms it produces in its lifetime. It is slow growing-only one inch a year-with a thick, massive, columnar trunk and wax-lik…

San Pedro Macho
San Pedro Macho

Echinopsis peruviana

This species is closely related to Echinopsis pachanoi and the two are sometimes confused with each other. The columnar Echinopsis peruviana is a branching, tree-like specimen that reaches fifteen feet tall. San Pedro ma…

Sandpaper Verbena
Sandpaper Verbena

Verbena rigida

Sandpaper Verbena has large, rough sandpaper-like leaves and stiff, upright branches. <i>Verbena rigida</i> is one of the largest members of the verbena family, growing to 2 feet tall by 4 feet wide. It is very hardy and…

Santa Rita Prickly Pear
Santa Rita Prickly Pear

Opuntia santa-rita

This low-growing prickly pear cactus forms large clumps and has a short trunk growing to heights of two to five feet with an equal spread. It produces flat, round, reddish-purple pads that grow to eight inches. The color…

Senita Cactus
Senita Cactus

Pachycereus schottii

The columnar cactus grows fifteen feet tall and about ten feet wide, branching upwards from its strong base at ground level to form thickets. Each stem produces about five to ten ribs and clusters of areolas with bristle…

Shaggy Head Agave
Shaggy Head Agave

Agave multifilifera

The striking agave grows in a single, dense rosette reaching three feet tall with a four to five foot spread. It has a short, terminal spine and numerous, medium-green leaves with many fibers growing along the leaf margi…

Sharkskin Agave
Sharkskin Agave

Agave nickelsiae x scabra ‘Sharkskin’

This elegant fast-grower is named for its uniformly spaced, leathery leaves that have the texture of shark skin. It is an admired agave growing from two to three feet tall and three to four feet wide. The sharkskin agave…

Shortleaf Aloe
Shortleaf Aloe

Aloe brevifolia

The low-growing, clumping aloe is stem-less and grows eighteen inches tall and nine to twelve inches wide. It forms small, tight rosettes of deep, blue-green, triangular, fleshy leaves with white spots and white teeth al…

Shrubby Bulbine
Shrubby Bulbine

Bulbine frutescens

The succulent evergreen with fleshy, smooth, aloe-like green leaves is low-maintenance and easy to grow. It spreads by underground rhizomes, creating clumps of growth that reach heights of eighteen inches and spreads of…

Silver Torch Cactus
Silver Torch Cactus

Cleistocactus strausii

This striking cactus develops slender columns up to eight to ten feet tall. It is a vigorous grower that has interesting, silvery blue spines on hairy, bluish-gray columns. The silver torch begins to flower when the colu…

Sky Flower
Sky Flower

Duranta erecta

Sky flower is a showy evergreen that grows eighteen feet tall and wide, if it doesn’t freeze back. It is a multi-trunk plant with arching branches that droop and trail in a downward appearance. Some species have spines o…

Smooth Agave
Smooth Agave

Agave desmettiana

This upright plant forms a beautiful, symmetrical rosette shape with slightly arching leaves and grows three feet tall and wide. It has light, bluish-green foliage with smooth edges and a sharp spine at its tip. Sometime…