New Plant Selections

Acacia redolens Desert Carpet™ ...Native to inland areas of Western Australia, Acacia redolens has been used extensively in southern California and Arizona to cover large areas inexpensively. In Arizona, it is commonly referred to as the “Freeway acacia”, since the Arizona Department of Transportation has used it since the early 1970’s to stabilize and cover banks along Phoenix rights-of-way. Seedlings of Acacia redolens vary widely in their growth habits, often reaching heights in excess of six feet. The Desert Carpet™ clone was selected from the first Phoenix freeway plantings for its prostrate growth habit, and was released by Mountain States Wholesale Nursery in 1984. Since that time, this groundcover has performed consistently on many projects, and years after installation has maintained a height of only twenty-four inches. One plant can spread to a width of twelve feet, although we have observed that the cutting-grown Desert Carpet™ plants are slower to establish and reach their mature size than seedlings. The slower growth rate and prostrate nature of this clone should reduce maintenance costs, since pruning is not necessary to control vertical growth. Instead of true leaves, Acacia redolens has thick, leathery, gray-green phyllodes. This plant blooms in the spring with small yellow flowers. Freeway acacia will tolerate low temperatures of 12-15 degrees Fahrenheit, alkaline and slightly saline soils, and does not seem to be choosy about soil types. In coastal areas it requires little or no supplemental irrigation, but does require regular irrigation in hot desert regions. Desert Carpet™ seems to be disease and pest free.

Agave desmettiana...This agave is similar in appearance to the lush Agave weberi, but smaller. Agave desmettiana grows to three feet tall and wide, with smooth, broad, gray-green leaves. This adaptable accent plant can be planted in many exposures, from full sun to shade. Since its leaves do have sharp terminal spines, be cautious about using this agave near pedestrian areas. Agave desmettiana will suffer leaf damage at about 25° F.

Agave geminiflora…Twin-flowered agave is incredibly adaptable. It tolerates full sun to full shade exposures; one California nursery even grows it as an interior plant! In full sun, its leaves are stiff, and you’ll need to be careful of the terminal spines. However, in part shade the leaves become more pliable, and the sharp tip is not as much of a concern. Plant this agave in the ground, or in pots. A mature plant will form a symmetrical rosette to three feet tall and wide. Agave geminiflora has narrow, dark green leaves. When temperatures drop to the low 20’s this plant can show some tip burn.

Baccharis hybrid ‘Starn’ (P.P.A.F.) Thompson™… When Dr. Tommy Thompson and Dr. Chi Won Lee of the University of Arizona released Baccharis hybrid ‘Centennial’, it filled a great void in our plant palette. Their research has been carried on, and now the improved Thompson™ clone is available. Since Baccharis ‘Centennial’ is a female plant, it has two undesirable characteristics. First, it produces pappus, or white “fluff”, which litters the landscape and reduces the aesthetic appearance of the plants for a short period of time. Also, since ‘Centennial’ is a female plant, it can be pollinated by nearby male Baccharis sarothroides (Desert broom), and seedlings often result. This is why you sometimes see stands of ‘Centennial’ with taller Baccharis plants growing up through them. The Thompson™ clone is a male plant, eliminating these two negative characteristics. Also, Thompson™ was selected from the next generation after ‘Centennial’, and has 25% more Baccharis sarothroides blood for heat and disease resistance. The growth habits and uses of these two clones are essentially the same: both grow to about 3 feet tall by 4-5 feet wide, are evergreen with bright green foliage and inconspicuous flowers, and provide a low-maintenance, long-lived alternative for difficult locations. How do you tell the difference between the two clones? Thompson™ will have a patent tag!

Bulbine frutescens... We have two selections of this tough clumping perennial; the more common yellow-flowering form and a dwarf, compact, orange-flowering clone, called ‘Hallmark’. Native to South Africa, these plants have long, narrow, bright green leaves, and delicate-looking flower spikes. The yellow-flowering selection has a fairly open and leggy growth habit, forming fast-growing clumps to about 12 inches tall by 2-3 feet wide. The orange-flowering form is tighter and more compact. Both selections are hardy to the low teens, and bloom most of the year, slowing down during the summer months. These plants do best in light filtered shade. The yellow bulbine seems to be more heat tolerant than ‘Hallmark’.

Cercidium species ‘Desert Museum’... This hybrid palo verde is a three-way cross between Parkinsonia aculeata, Cercidium microphyllum, and Cercidium floridum, and seems to combine the best qualities of all three plants. ‘Desert Museum’ grows very rapidly to 20 feet tall and wide in 3 to 5 years, after which it needs little or no irrigation. It is completely thornless, and produces very little litter, with few seed pods. It has a sturdy, upright growth habit which requires very little pruning or staking. It blooms over a long period of time, with the heaviest bloom from about mid-March to May 1. It also tends to bloom again in June and August. The yellow flowers are larger than any of its three “parents”. Probably best of all, it does not re-seed like the messy Parkinsonia aculeata!

Chrysactinia mexicana (Damianita)... This small, compact shrub grows to 2 feet tall and wide, and bears a very strong resemblance to turpentine bush, with needlelike green leaves and yellow daisy-like flowers. However, damianita blooms from March to September, while turpentine bush blooms from September to November. Combining the two plants would be a great way to prolong the color display! Damianita has wonderful-smelling foliage, and would be a great selection for sensory gardens. Damianita is a very tough, durable plant, tolerating extreme heat and cold, down to 0º F. Plant in full sun, and almost any soil. If this plant starts to look woody, prune it back severely in the early spring. Damianita ranges from New Mexico to west Texas and northeastern Mexico, at elevations of 2000 to 7000 feet.

Cuphea llavea (Bat-faced cuphea)...This water-loving plant is native to Mexico, where it grows along streambeds. In warm climates, it blooms from March to October with unusual red and purple flowers that look like a bat’s face. Due to its long bloom period and higher water requirements, it would make a nice substitute for annual color in planters and other landscape focal points. Just remember that this plant is not drought-tolerant! Bat-faced cuphea will grow to about 2-3 feet tall by 3 feet wide. Plant either in full sun, or in filtered sun locations such as under desert trees. While cold temperatures down to 25 degrees can burn the foliage, bat-faced cuphea recovers readily from the roots.

Dalea bicolor v. bicolor Monterrey Blue ^TM... The clone Monterrey Blue™ was selected from a bunch of seedlings that Ron Gass and Greg Starr brought back from their travels in Mexico. As you might have guessed, this clone was chosen because of its outstanding deep blue flowers, which give a much-needed spot of color in the fall months. Allow plenty of room for this shrub, since it can easily fill a space from 6-8 feet tall by 5-6 feet wide. Cold hardy to 5-10 º F, Monterrey Blue™ is a nice addition to the Las Vegas and El Paso plant palettes. Monterrey Blue™ is deciduous, but it grows rapidly enough that you could cut it back hard in the winter, and allow it to produce fresh spring growth. Plant in full sun and well-drained soil, if possible. An added bonus to this plant is that rabbits don’t seem to care for it!

Dalea capitata Sierra Gold™... This well-behaved ground cover grows to about 8 inches tall by 3 feet wide. Because of its compact size, Sierra Gold™ is a good selection for tight planting areas, such as small planters or medians. Its fine-textured, light green foliage has a fresh, lemony scent. We suspect that it tastes like lemon, too, because the rabbits seem to avoid it! Yellow flowers carpet Sierra Gold™ in the spring and the fall. Those of you in the high deserts will be happy to know that this plant is hardy to at least 5ºF, but it will be deciduous in the mid-20’s. The one drawback to this plant is that the whiteflies seem to like it, so some insecticide applications will be necessary in heavily infested areas around Phoenix. Plant in full sun for best results. No soil amendments should be necessary. In hot desert regions this plant requires some supplemental irrigation from spring to fall. Although most daleas native to Arizona and Mexico tend to rot out if overwatered, we have observed this plant thriving right next to turfgrass, where it receives heavy irrigation. More testing is needed to determine if it will tolerate coastal areas, or regions with high rainfall.

Dalea dorycnioides Cerro Azul ™... This evergreen shrub grows to about 5-6 feet tall and wide, with a naturally-rounded growth habit. Cerro Azul ™ was selected from a group of 100 seedlings for its showy spikes of purple-blue flowers. Now for the exciting part...Cerro Azul ™ is a winter bloomer! Flowers appear in the fall, and continue through winter and spring. While this plant prefers full sun exposures, it is tolerant of most soil types, including those with high clay contents. Cutting these plants back by ½ for the first three or four years will encourage denser growth and more flower production. Cerro Azul ™ is hardy in Tucson, and will probably tolerate temperatures down to 10ºF.

Dalea frutescens Sierra Negra ™... Looking for a fall bloomer? This shrub blooms heavily with purple flowers in October and November. Beware of bees, however...they really love these flowers! This plant is also popular because of its size, forming a nice rounded mound three to four feet tall by four feet across. I have seen this shrub growing happily in very hot locations, with a lot of reflected heat. The green foliage is very delicate, giving Sierra Negra ™ an airy appearance. Although this plant is deciduous in cold climates, it is very hardy, tolerating temperatures down to 0 ° F.

Dalea lutea Sierra Moonrise ™... When Sierra Moonrise ™ blooms in the late fall, the contrast between the deep green foliage and the yellow flowers is striking. In warmer areas this shrub is evergreen, but where temperatures drop to the mid-20’s, it becomes partly deciduous. We know that Sierra Moonrise ™ tolerates temperatures as low as 17ºF, but it has not been sufficiently tested at lower temperatures. Plant Sierra Moonrise™ in full sun or part shade, and allow plenty of room, since this shrub can grow to 6 feet tall and wide. As suggested for Cerro Azul ™, cut back plants by one half to two thirds in late winter to encourage dense growth and more profuse fall flowering. Rabbits do munch on this dalea when nothing else is available.

Dasylirion longissimum... This user-friendly accent plant is a great selection for high-traffic areas such as walkways, around swimming pools, near entries, etc. This grasslike plant does well in containers, and its symmetrical form provides a striking focal point. Its thin, stiff green leaves are completely unarmed, and have smooth edges. Eventually, its single trunk can grow to 6 feet, topped by a 5-foot-wide rounded head of leaves. The older, bottom leaves can be trimmed off to expose the trunk.

Dyssodia pentachaeta (Golden dyssodia)... The showy flowers of this short-lived perennial provide a carpet of bright yellow color in the spring, summer and fall. Individual plants are only about six inches tall by twelve inches wide. They can either be planted en masse, or scattered throughout the garden. Golden dyssodia naturalizes easily, so don't be surprised if this plant "migrates" around the landscape each year. For best results, plant in full sun, and in well-drained soil. It does not require much water! Golden dyssodia is hardy to at least 10 ° F.

Eucalyptus formanii (Forman's Eucalyptus)… This small tree resembles a big feathery cassia, with needlelike gray leaves and a bushy growth habit. Forman's Eucalyptus wants to grow as a multi, to about 12-18 feet tall and wide. It has attractive, rough gray bark, and blooms with masses of creamy white flowers. This eucalyptus is the most cold-hardy species we carry, tolerating temperatures down to 10° F.

Eucalyptus papuana (Ghost Gum)... Growing to about 40 feet tall by 25 feet wide, this tree has powdery white trunks, which contrast nicely with its large, light green leaves. This eucalyptus species has a semi-weeping growth habit, and produces very little litter. ADOT has liked its performance on older freeway rights-of-way, and continues to include it in the designs for new landscape areas.

Eucalyptus salmonophloia (Salmon Gum)... One of the most beautiful features of this tree is its smooth, salmon-colored bark. Salmon gum also has narrow, shiny, bright green leaves which shimmer in the sunlight. Although trees up to 80 feet tall have been reported in Australia, older trees in Phoenix are only 40 feet tall and wide. It is slow-growing, and will be one of the best choices for residential landscapes. Salmon gum is moderately salt-tolerant. In Western Australia, this tree has been a main source of timber and firewood.

Eucalyptus salubris (Gimlet)... Very similar in appearance to Salmon gum, Eucalyptus salubris has narrow, shiny green leaves, with smooth red-brown bark. Gimlet is a smaller tree, growing to about 20-25 feet in the Phoenix area. Like salmon gum, it is also slow-growing. This species of eucalyptus is especially suitable for sites with heavy clay soils, although it will suffer if over watered.

Eucalyptus sargentii (Salt River Mallet)... This extremely salt-tolerant tree can grow to 30-40 feet tall and wide under cultivation. It has been useful as a windbreak in salty soils. An attractive tree, this eucalyptus has narrow, gray-green leaves and smooth brown branches. The dark gray bark exfoliates in strips from the trunk.

Eupatorium greggii Boothill ™... What a butterfly attractant! This small perennial has soft-textured lavender flowers that resemble those of Ageratum species. In habitat, Eupatorium greggii is found in hot, dry, rocky areas, where it grows to 18 inches to 2 feet tall by 2-3 feet wide. Boothill ™ blooms from spring to fall. In low deserts, plant Boothill ™ in part shade for best results. This clone is moderately drought-tolerant, preferring regular irrigation to look its best. Boothill ™ will freeze back when temperatures drop to 5° F, but recovers quickly from underground stems.

Hesperaloe parviflora 'Yellow' (Yellow yucca)... A clumping perennial with long, gray-green leaves, Hesperaloe parviflora grows slowly to form a grasslike clump three to four feet tall and wide. From spring through fall, it produces five-foot-tall flower spikes. Red-flowering plants have been a staple in southwestern landscapes for many years. This is simply a yellow-flowering selection. Use this tough accent plant in full sun. Since it also tolerates reflected heat, yellow yucca is a reliable plant to use along sidewalks, in parking lots, etc. Tolerant of temperature extremes, yellow yucca is cold-hardy to 0 °F. Once established, it requires little or no irrigation. All in all, yellow yucca is one of the toughest and most maintenance-free plants we grow!

Hesperaloe species (Bell Flower Hesperaloe)... Bell Flower Hesperaloe looks like a small Hesperaloe funifera, growing to only 3 feet tall and wide. However, its flowers are pink, instead of creamy white like the Giant Hesperaloe. The 1/2 inch wide, bright green leaves have attractive white threads along their margins. Plant in full sun and well-draining soil. Native to Nuevo Leon, Mexico, this plant has been tested to 5º F.

Hymenoxys acaulis (Angelita Daisy)...This perennial is native to the southwestern U.S., where it occurs most often at elevations from 4000 to 7000 feet, on dry rocky slopes and mesas. Angelita daisy bears a strong resemblance to Baileya multiradiata (desert marigold). However, the foliage is green rather than gray, and the flower is a deeper gold color. Forming rounded clumps to 18 inches tall and wide, Hymenoxys acaulis is a wonderful plant to use as a border in front of larger shrubs. If water is available, it will naturalize in the landscape. The truly amazing thing is that this plant actually looks good in a container, which will be welcome news for our retail nursery customers! In Phoenix, this plant blooms all year, with especially heavy bloom in the spring and fall months. This prolonged bloom period results in many dried flower stalks, which can make the plants look scruffy. We recommend cutting off the old flower spikes occasionally to rejuvenate the plant and initiate new flower production. Angelita daisy seems to prefer well-drained soils and full sun. Although it is more forgiving of irrigation than desert marigold, it can still rot out if overwatered. It is very cold-hardy and drought-tolerant, and handles our summer heat exceptionally well.

Leucophyllum pruinosum Sierra Bouquet ™... This selection of Texas ranger was collected in Mexico, and was chosen for the wonderful fragrance of deep purple flowers... they smell like grape bubble gum! Like the other Leucophyllums, Sierra Bouquet ™ blooms in the summer and fall, when the humidity increases. Sierra Bouquet™ has silver-gray foliage and a rather sprawling growth habit, growing to six feet tall and wide. Consider using this shrub in masses to capitalize on the fragrance of the flowers. It is hardy to 10º F, and thrives in full sun and reflected heat.

Malephora lutea (Rocky Point Ice Plant)… Native to South Africa, this lush green ground cover seems to handle our summer heat better than other ice plants. It blooms most of the year with yellow flowers. An aggressive grower, Malephora lutea can reach a size of 8 inches tall by 4-5 feet wide in one growing season. In locations with extreme reflected heat, this plant can brown out somewhat. If this occurs, just cut plants back in the fall to the green growth, and they should recover quickly. A note of caution… birds seem to love the succulent green leaves!

Muhlenbergia capillaris Regal Mist ™...We feel that this ornamental grass shows great promise for many different regions of the country. Native to humid southeastern Texas, this grass has adapted extremely well to the hot,dry conditions of deserts in Arizona and Nevada. In fact, it has performed incredibly well in Las Vegas, which is cursed with poor soils, high winds, high summer temperatures, and cold winters. Regal Mist™ is also happy in heavy soils, with ample irrigation. In short, it has worked everywhere it has been tried, so far! It is hardy to at least 0º F. Regal Mist™ has narrow, dark green, glossy leaves. It grows quickly to form a rounded clump to three feet tall and wide. The flower spikes on this grass have attracted a lot of attention…they form misty masses of pink to purple flowers in October and November. We recommend cutting this plant back in early spring to cut off the dead flower spikes and any dormant foliage. This grass is a favorite of landscape and golf course architects, who generally use it in large masses.

Muhlenbergia lindheimeri Autumn Glow ™... This ornamental grass makes a great backdrop for the Regal Mist ™. It blooms at the same time, with tall spikes of light yellow flowers. The plant itself is also a little taller than Regal Mist ™, to about five feet. Autumn Glow ™ has narrow, light green leaves, and looks very similar to Muhlenbergia rigens when not in bloom. All of the muhlenbergias we grow are very adaptable, tolerating full sun to almost full shade, and most soil types. They are also a good choice for retention basins or other areas that receive periodic flooding. All of these grasses are root hardy to 0º F.

Nolina bigelovii... Native to Arizona, this accent plant handles both the heat and cold well, tolerating temperatures down to at least 10º F. This plant will grow slowly to 6 - 8 feet tall by 4 - 5 feet wide. It blooms in the late spring to summer with spikes of creamy white flowers. Be careful not to over-water this plant, or the roots will rot!

Nolina matapensis (Tree Bear Grass)... A Mexican relative of our native bear grass, Nolina matapensis is a showier, more lush-looking species with 3-foot long, one half inch wide, bright green leaves. While this plant will eventually develop a branching form to 15 feet tall, its trunk develops very slowly, to 3 inches a year. It provides a lush green, low-maintenance focal point on golf courses, freeways, and other commercial and residential projects. Individual plants need 5 - 6 feet to spread out, so be careful not to plant them in tight spaces. While the leaves of this accent plant are unarmed, its edges are sharp, and are not pleasant to walk through! As with other Nolina species, this plant is very cold-hardy, to at least 5 degrees F.

Opuntia santa rita Tubac ™... This new clone of prickly pear was selected for its great fall and winter color. In the cool weather its pads turn an especially rich shade of purple. Eventually this cactus can grow to four feet tall by six feet across.

Penstemon species... There are so many wonderful Penstemon species to try in the garden, that is difficult to select just a few. Most of the penstemons are perennials with a basal rosette of foliage, which send up spikes of tubular flowers in the spring and early summer. They add incredible color to the landscape, and attract hummingbirds as well! Penstemons come in a wide range of colors, including blue, purple, pink, and red. After they finish blooming, allow the flower spikes to dry on the plant. Then cut off the spikes and sprinkle the seed in the garden to increase next year’s mass of color. There are two new species to try: (1) Penstemon triflorus, which has short, 18 inch spikes of dark pink-purple flowers. Along the stem, the flowers occur in clusters of three. (2) Penstemon clevelandii, native to southern and Baja California, with spikes of clear, bright pink flowers to two or two and a half feet tall.

Sphaeralcea ambigua Louis Hamilton ™... The globe mallow is a common desert shrub that usually has light orange flowers. This selection has especially large brilliant orange-red flowers! Globe mallow grows to about 2 - 3 feet tall and wide. It is extremely tough, tolerating extreme heat and cold, and growing in virtually any soils.

Tecoma species ‘Orange Jubilee’... This large shrub is probably a hybrid between Tecoma stans (Arizona Yellow Bell) and Tecomaria capensis. The growth habit is very similar to that of Arizona Yellow Bell, but this plant has orange flowers instead of yellow. An added advantage is that it produces very few, if any, seed pods! The foliage will freeze back in the mid-20’s, but will recover quickly in the late spring. It is a favorite in Las Vegas! It could possibly form a small tree in frost-free areas.

Zephyranthes species... The white rain lily (Zephyranthes candida) has dark glossy green, narrow leaves, and white waxy flowers in the fall months. The rain lilies are wonderful plants to use in tight spaces, since they only grow to twelve inches tall by 12-18 inches wide. They will tolerate full sun, but seem to prefer some filtered shade. A newer introduction, Zephyranthes sulphurea (citrina), has the same deep-green narrow leaves, but has bright yellow flowers. Another rain lily, Zephyranthes grandiflora, has large pink flowers. If rain lilies dry out, they may die back to the ground. Do not be alarmed if this happens, as they will grow back from underground bulbs when water is applied.

Zexmenia hispida Devil’s River ™... Native to Texas and Mexico, this long-lived relative of Wedelia trilobata looks a lot like our native Viguiera deltoidea (Goldeneye). A small, well-behaved shrub, Devil’s River ™ grows to 2 - 3 feet tall and wide. When planted in full sun, it forms a rounded mound of bright green leaves, and blooms profusely with yellow daisy flowers from late spring to late fall. In part shade, it acts more like a ground cover, and continues to bloom, but not as spectacularly. In warmer areas Devil’s River ™ behaves like a woody evergreen shrub, while in colder climates it can go deciduous and freeze back to the ground (it recovers quickly in the spring).