Submitted by blazej on Mon, 11/05/2018 - 10:32
Hans Hansen

MANGAVES ARE AN intergeneric hybrid between a Manfreda and an Agave.  My introduction to this fascinating group of plants goes back to the mid-1990s.  At that time I was Director of Research and Development at Shady Oaks Nursery in Waseca, Minnesota. I was managing a tissue culture lab, my primary crop was hostas, and I worked closely with hosta hybridizers helping them introduce their new selections into the wholesale market. One of the hybridizers was Tony Avent of Plant Delights Nursery in Raleigh, North Carolina. He had several Agave hybrids and forms of species he was trying to build up numbers of to put into his catalog. After twisting my arm and telling me they were hosta’s closest relative I agreed and began working on propagating them. Manfreda ‘Chocolate Chip’ soon followed as well as a number of variegated forms of Agave.

The first known Mangave hybrid was identified by Carl Shoenfeld of Yucca Do Nursery in Hempstead, Texas.  In the late 1990s, Carl was botanizing in Mexico and collected seed from a plant he called Manfreda undulata (possibly Manfreda variegata). When the seeds germinated at the nursery, two of the seedlings had incredible vigor compared to the rest of the batch. The two plants were grown to maturity and developed into three-foot (1 m) wide clumps of broad, thick leaves with such intense burgundy spotting as to appear almost a solid burgundy color. During a visit to Yucca Do Nursery, Tony Avent saw the seedlings and suggested that a nearby Agave celsii must have crossed with the parent Manfreda in the wild. Tony and Carl coined the name Mangave to designate the hybrid, making it the first documented hybrid between Agave and Manfreda.  The best of the two seedlings was given a cultivar name of ‘Macho Mocha’ and sent to Shady Oaks to be tissue cultured. It was introduced into the retail trade by Plant Delights Nursery and Yucca Do Nursery in 2004.

 During its propagation I isolated two variegated forms, ‘Expresso’ having a wide creamy white margin, and ‘Cappuccino’ – the reverse variegation pattern with a dramatic creamy-white center.  The hardiness of these is about zone 8-10. When the plant flowers the scape reaches up to eight feet (2.4 m) in height with dark red flowers at the top of the scape.

In 2009 I moved to western Michigan to work at Walters Gardens, the nation’s leading grower of wholesale perennials.  As Director of New Plant Development, I had the opportunity to spend most of my working hours hybridizing perennials.  My interest in Agave and Manfreda increased; by now I had grown several forms of Manfreda virginiana in both of my gardens, including forms with remarkable red coloration. I acquired as many Manfreda as I could find, as well as Mangave ‘Bloodspot’, the second known Mangave hybrid with Agave macroacantha as the pollen parent.  The benefit of breeding with Manfreda was the rapid growth rate, dependable annual flowering, and the red-spotted pigment that was easily transferred to their offspring if selections of Manfreda that had the most dramatic spotting and leaf coloration were used as parents. In some species, the red pigment was so dark as to appear nearly chocolate brown. Over the next several years I reached out to friends with Agave collections when my Manfreda and Mangave came into flower. They were generous with sharing Agave pollen, and I was able to make many viable crosses. 

The first Mangave introduction from my work was ‘Pineapple Express’, a cross from 2011 between Mangave ‘Jaguar’ and Mangave ‘Bloodspot’ (a Japanese hybrid between an unknown Manfreda and Agave macroacantha).  This rapid-growing hybrid forms an upright symmetrical clump of fleshy dark green leaves covered with pronounced dark burgundy spots. Very tiny harmless spines line the leaf margins. The overall effect from a distance with the upright form and habit really does resemble the top of a pineapple. Its hardiness is zone 8-11 

Two other releases from 2011 work that hit the market later were ‘Bad Hair Day’ and ‘Man of Steel’. ‘Bad Hair Day’ is a hybrid between Manfreda maculosa and Agave geminiflora (the twin-flowered agave). It is a personal favorite of mine for the profusion of long, narrow, rubbery leaves that look amazing in face containers.  This selection remains vegetative for a very long time (six years to flower from seed).  In the ground, the plant seems to have less uniform symmetry – throwing a few unruly leaves and begging for a suitable name.  Direct sunlight turns the foliage from dark green to nearly burgundy with the profusion of tiny spots.   A seven-foot (2 m) flower stem is covered with over 100 rose-colored flowers produced in pairs, just like the Agave pollen parent.  Unlike the rest of the introductions, the original rosette does not seem to die after flowering (like the Agave parent), nor does it seem to offset.  Mangave ‘Bad Hair Day’ seems to be one of the hardiest releases to date, overwintering several years in Raleigh, North Carolina,  (Zone 7b). The size in the garden is about 12 inches (30 cm) by 30 inches (75 cm).

‘Man of Steel’ has thick, narrow steel blue foliage that picks up a bronze patina in full sun.  This cross involves Agave striata, and it has a strong resemblance to its pollen parent.   Terminal spines change from flexible when young to strong at maturity.  A slower growing selection, the original seedling has not yet flowered to date (seven years).  With A. striata in the background, it should have some hardiness, I’m guessing Zone 8-11. Plant size is 12 inches (30 cm) tall by 20 inches (50 cm) wide. One of the benefits of a slower growth rate and maturity is that the original rosette stays attractive longer before flowering.

2012 was a busy year for making Mangave crosses. Some of the introductions from that year include ‘Lavender Lady’, ‘Mission to Mars’, ‘Silver Fox’, ‘Purple People Eater’, ‘Moonglow’ and ‘Inkblot’.

‘Moonglow’ and ‘Inkblot’ are sister seedlings from the cross between Mangave ‘Bloodspot’ and a Manfreda.  This backcross between a Mangave to a Manfreda produced rapidly growing plants with a more flattened growth habit and succulent leaves.  They also have a quicker life cycle, flowering in less than three years from tissue culture in the greenhouse. ‘Moonglow’ has the flatter habit of the two, with succulent leaves that are a blend of silver and very dark purple.  Very benign spines line the leaf margins of the 6-inch (15 cm) by 24-inch (60 cm) plants.  Both selections are quite tender (Zone 9-11)  Because of the predominately Manfreda bloodline these siblings have no spines or lethal teeth. 

‘Inkblot’ has an arching habit where the foliage radiates downward from the center of the plant.  Plum-colored spots nearly cover the leaves with smoky-gray patterns appearing between spots.  Like its sister seedling, 7-foot (2 m) flower spikes with leaf bracts tower above the foliage and bear dozens of maroon flowers.  Basal offsets usually appear a year before flowering to regenerate the plant. The in-ground size is 8 inches (20 cm) tall by 20 inches (50 cm) wide.

‘Lavender Lady’, a hybrid between a Mangave and Agave attenuata (the foxtail agave), is one of the most architectural introductions. The plant forms a solitary clump of ovate, dusty-purple leaves. Minute white spines lining the leaf margins set off the lavender-purple leaf color, while the small terminal spine is cinnamon brown. Slow to reach maturity, this flowered five years from seed producing a long elephant trunk-like spike that cascaded down from the top third, covered in hundreds of yellow flowers.  This is one of the most tender varieties. Leaves burn with a few degrees of frost. It is best showcased in a container in zones with any degree of freezing. Plant size is 12 inches (30 cm) tall by 20 inches (50 cm) wide.  It is a personal favorite, very Agave-looking, although without spines.  Its lavender cast is among the most distinct of the hybrids. 

‘Silver Fox’ was from a cross between a Mangave and Agave gypsophila.  This stunning plant has frosted silvery-gray foliage with a bluish-purple underlay caused by the myriad of tiny spots.  Plants form a symmetrical arching mound, the leaves slightly folded have a gently undulating wave courtesy of the pollen parent.  Well defined marginal teeth add character.  Seven-foot (2 m) flower scapes produced dozens of yellow flowers at maturity.  If the stems are allowed to stay on the plant after flowering, small aerial plantlets develop along the stem. This flowered five years from seed.

‘Catch a Wave’ combined the genetics of an unnamed Mangave seedling with Agave gypsophila and Agave colorata. The free-form architectural plant has thick blue leaves with a glaucous overlay.  The concave, gently undulating margins are lined with thin white teeth.  Full direct sun draws out plum-colored spotting.  The dramatic plant will form a 20-inch (50 cm) by 30-inch (76 cm) clump over time, and 6-foot (1.8 m) flower stems bear mahogany flowers.  Hardiness is from Zones 9-11.  Because of the predominately Agave genetics in the cross, this hybrid looks very Agave-like. It has enough Manfreda heritage to have a nice growth rate and can achieve a large architectural agave-looking plant at a fraction of the time needed to raise an agave with similar form and size.

‘Falling Waters’ is one of the largest hybrids, 12 inches (30 cm) tall and over 30 inches (76 cm) wide.  This Manfreda crossed with Agave ovatifolia (whale tongue agave) produces a large rosette comprised of glaucous blue-green folded leaves that gracefully arch downward.  Large jagged marginal teeth add character. Its beautiful form is best showcased in a large container to allow its foliage to cascade gracefully, or may be used in the landscape in Zones 7b to 11.  A sister seedling evaluated in North Carolina flowered in 5 years producing an eight-foot (2.4 m) flower stem with many yellow flowers.

‘Spotty Dotty’ marries the genes of a Mangave hybrid and Agave bovicornuta (the cow horn agave).  One of the most vigorous of the introductions, ‘Spotty Dotty’ forms a 10 inch (25 cm) tall by 3 foot (90 cm) wide specimen.  The lighter green leaves are heavily spotted with large red dots.  Tiny spines line the leaf margins.  Because of the tender Agave species parentage, hardiness is estimated to be Zones 9-11. This selection is a favorite because of the dramatic spotting, large size, and quick time to reach maturity.

As a rule, Mangaves tend to be incredibly fast growers compared to their pollen parents Agave. This makes them more economical and user-friendly from a nurseryman’s point of view.  In fact, some varieties are almost challenging to hold for any length of time in a cell pack in greenhouse conditions.  This quick growth rate is reflected in the amount of time taken to reach maturity and flower.  Agaves typically take between seven and 25 years depending on the species. The Mangaves can take between two and seven years, again depending on the genetics used. As my breeding program has evolved and more crosses come into flower and get worked back into the breeding program, plants are beginning to look more like Agaves with stronger teeth and firmer, less succulent leaves. The following are examples of hybrids with quite an agave-like structure and form. 

‘Racing Stripes’ resembles  Agave lophantha (the thorn crested agave).  This cross of a Mangave and Agave lophantha ‘Band Aid’ features the hallmark central yellow band of A. lophantha with a faster growth rate and gently arching leaves.  Agave ‘Band Aid’ was a clonal selection of the species with wider leaves and a slower tendency to offset.  The rich dark green leaves make the central band pop, and serrated spines line the leaf margins of the compact 8-inch (20 cm) by 14-inch (35 cm) plant. 

Mangave ‘Tooth Fairy’ is a cross between a Mangave and Agave shawii.  This plant is comprised of a rosette of small thick, gray-blue leaves lined with very pronounced marginal and terminal spines that emerge yellow and age to cinnamon red before eventually maturing to mahogany brown. Like several agaves, this hybrid has a beautiful leaf pattern on the upper surface where the leaf pattern and spines are imprinted from the previous unfurling leaf. Exaggerated terminal red spines may reach 1.5 inches (3.8 cm).  With Agave shawii and A. macroacantha in the background, this is quite frost sensitive.  It has not yet flowered.  Unlike my earlier work, this selection capitalizes on the quantity and number of terminal and marginal spines.

‘Iron Man’ combines a Mangave hybrid with Agave montana (the mountain Agave).  It is large, 20 inches (50 cm) tall by 36 inches (90 cm) wide. The wide dark green leaves and arched leaf tips are reminiscent of Agave salmiana var. ferox with the upper surface leaf imprinting. ‘Iron Man’ is hardy to Zone 8-11.

‘Mission to Mars’ is one of the largest mangaves, both in leaf length and width and clump size, reaching 2 feet (60 cm) by 4 feet (120 cm). The parent Mangave was a Plant Delights Nursery hybrid of Manfreda jaliscana and Agave x pseudoferox crossed with Agave shawii. ‘Mission to Mars’ has 2-foot (60cm) long leaves that are slightly folded, arching and covered with so many intense ruby spots the leaves appear red from a distance. The effect is magnified in full sun. A great landscape specimen where hardy (Zones 8-11), it quickly will fill a large container for patio use as well. Moderate to reach adulthood, flowering occurred in four years here.

‘Redwing’ (Manfreda sp. x Agave shawii) shows the most red pigment to date. Under full sun conditions, the leaves are carnation red. The large symmetrical rosette is comprised of short wedge-shaped leaves that are among the most beautiful of any Mangave.  This selection has yet to flower. 

In the course of working with mangaves, I found a sport with a yellow variegation pattern in a tissue culture batch of ‘Jaguar’. After growing it on for several years it became one of the most incredible mangaves I’ve seen. The yellow leaf margins turned nearly orange in full sun.  Fleshy leaves with an absence of spines make this ideal for containers or landscaping.  It is hardy in Zones 8-10. Flower stems are nine feet (2.7 m) or taller on established plants.  Its arching habit and size make it ideal for elevated containers and urns where its details can be appreciated up close.

Over the course of time, I think things eventually go full circle. Long before I began working with Agave and Mangave, and even before I met Tony Avent, I was hybridizing hostas, primarily for variegated foliage.  The flower structure, length of bloom time (both flowers are receptive for pollen for about one day) are surprisingly similar.  Eventually, I got a break and began developing breeding lines for variegation. Like hostas, the variegation in Mangave is only transmitted maternally, and the resulting seedlings must be aged until the variegation pattern is stabilized.  Personally, I think variegated Mangave are the most dramatic, as I have always had a weakness for variegated foliage.  The first release from my variegated breeding lines was Mangave ‘Navajo Princess’, using the variegated breeding line of Manfreda maculosa with Agave montana.  This selection has dark green leaves with a clean white margin.  Like many hostas, a lighter green area appears where the margin and leaf center overlap.  The red spotting on the leaf center appears pinker on the white margins especially under stress or high light.  With the high elevation Mexican species of Agave as a parent, hardiness should be about Zones 7b-11.

Eventually, my goal is to work towards hardier selections. I’ve had difficulty getting pollen of some of the hardiest Agave as their growth rate is slower than many tender types, and the Rocky Mountain forms dislike the humidity of the southeastern states. Hardiness also is often directly related to winter moisture more so than temperature. I’ve had seedlings from the same cross overwinter outside with protection from heavy wet snow while sister seedlings perish planted several feet away unprotected.  Some plants have died back from winter wet and cold above ground but re-emerged weaker.

Of all the breeding projects I’ve been privileged to be a part of, the Mangave project has been the most rewarding for me. Seeing the genetic diversity of leaf shape, architectural form, growth rate, and red and purple coloration has been fascinating.  Their quick life cycle has allowed me to make several generations of crosses. One would have to live many more years to accomplish the same breeding lines with Agave.

From a gardener’s point of view, Mangave are impressive in the landscape. They do for sun what hostas can do in the shade.  The imposing size and leaf form and structure lend them as specimens in the landscape. Their summer moisture requirements are comparable to many other perennials. I love combining them in groups of three or five in my conifer beds, as specimens in the rock garden, or focal points along the sidewalk in front of my house.  Fine textured plants like grasses (SporobolusFestucaStipa) look great with them, as well as ground-cover sedums. Tall cacti like cane cholla provide height and backdrop. Mangave are quite collectible, and numerous gardeners have assembled excellent collections and showcased them in ceramic glazed pots on patios – a perfect way to display collections and allow gardeners to bring them indoors in climates out of their hardiness zones.