Agave mckelveyana is a modestly-sized century plant which is endemic to northwestern Arizona, mainly within Mohave and Yavapai Counties. The individual above is growing within 3 miles of my cactus rancho in the southwestern Hualapai Mountains not far from Yucca, Arizona. The common name, obviously, is McKelvey agave.

This particular individual is surely one of the nicest leaf forms of Agave mckelveyana that I have ever come across. The large and slightly reddish marginal teeth, strongly gray-and-green-banded leaves, prominent bud impressions on the leaves, and slightly corkscrewing terminal spines all combine to make this into a singularly nice specimen.

I’m leading the post off with this particularly grand example to highlight why this is an agave worth growing. However it should be noted that most are more average-looking. Still nice, mind you, but not this exceptional. Those are featured farther down. Keep reading, please. 😉

The substrate rock here is Hualapai granite, a coarse-grained stone with large crystals of feldspar that lends itself towards rounded shapes as it weathers over eons. The soils derived from this granite are suitable for a wide variety of succulents – I’ve counted approximately 25 species of cacti and other succulents native to the immediate region within a few miles of me. An Engelmann hedgehog (Echinocereus engelmannii) is snugged up next to the agave in the photo above.

Another Agave mckelveyana grows in the granitic soil between stacked piles of rounded boulders alongside saguaro cacti (Carnegiea gigantea). This region is close to the northernmost natural range of the saguaro – they extend perhaps another 20 to 25 miles farther north in a narrow band along the western slopes of the Hualapai Range and stop in a canyon about 12 or 15 miles south of the city of Kingman, Arizona. Wild saguaros grow no farther north than that, although obviously ones planted in landscapes in Kingman, Las Vegas, and other Mojave Desert cities extend the artificial range significantly farther.

The Hualapai Mountains on both the eastern and western slopes are characterized by a mix of Sonoran Desert and Mojave Desert vegetation. This narrow and discontinuous band of intermingling occurs from northeast of Yucca AZ, heads southeastwards towards Wikieup AZ, and comes to an end in the vicinity of Congress and Wickenburg AZ, a distance of about 125 miles total. The signature plant of the Sonoran Desert is the saguaro, while Joshua trees (Yucca brevifolia) are the indicator species of the Mojave Desert. It is here, and only here in this limited and patchy region of distribution where those two charismatic and iconic species co-occur in the wild.

Another view of how saguaros and Joshua trees grow together southeast of Yucca, AZ. The Hualapai granite boulders on the hills are enormous, with many of them being the size of average rooms inside houses at 10 to 20 feet tall and wide. Evidence of this can be seen from comparison to saguaros in between the boulders which are 20 to 30 feet tall with arms, looking like toys next to the giant rocks.

A nice, but more typical-appearing Agave mckelveyana grows amidst the Joshuas and saguaros. The cactus to the left is buckhorn cholla (Cylindropuntia acanthocarpa) and the evergreen shrubs to the center and right of the Joshua tree are the leguminous Arizona mescal bean (Sophora arizonica), which like the agave is also endemic to the state of Arizona. These beautiful and interesting xeric shrubs will be the subject of a separate post at some point in the future.

Ron stands next to a red barrel cactus (Ferocactus acanthodes) in the same locale as these McKelvey agaves. The barrel is about 6 feet tall and at least 350 to 400 pounds in weight at that substantial diameter. Most feros topple over by the time they reach this point since the ropy basal roots and lack of woody support ribs inside the plants cannot support the weight of the plant once it starts leaning, as most barrels eventually do. But ones supported by rocks don’t lean as much and tend to not be undermined by the burrowing activities of rodents, giving them a greater chance for survival to this great size.

Many McKelvey agaves grow somewhat hidden in large vegetation, such as these tucked underneath a catclaw acacia (Acacia greggii). The agaves tend to prefer middle and higher elevations and only occupy the upper edges of the desert zones where plant growth is sparser. They do not naturally occur in lower deserts. Seedlings survive best within the protective confines of larger nurse plants until they are big enough to venture into the world. The dead rosette is the remains of one that bloomed a year or two prior, and which appears to have been decapitated by browsing cattle.

These agaves do offset and clumps of 2 to 6 individuals are common. They mostly grow in chaparral and pinon-juniper habitat in western Arizona at elevations ranging from 3000 to 7000 feet (900 to 2100 meters). They are not truly desert plants although again, some do survive in the transition zones between their preferred Arizona Interior Chaparral habitat and the Upper Sonoran Desert, where rainfall may be as low as 8 to 9 inches (20-25 cm) a year. However they clearly do better in places getting 14 to 20 inches (35 to 50 cm) per year.

This nearly flowering-size rosette of Agave mckelveyana is growing in Arizona Interior Chaparral habitat at about 4200 feet (1300 meters) elevation east of Wikieup, Arizona in May 2018. This is a biome characterized by woody shrubs between one and six feet high, which grows fairly densely on cooler, shadier north slopes and shorter and more open on sunnier, drier south-facing ones. The agaves grow in all types of exposure situations, from very exposed rocky outcrops to being buried completely within scrub oaks (Quercus turbinella) and silk tassel bushes (Garrya wrightii), with only the tall flower spikes emerging at bloom time. The cacti blooming in the background are Engelmann prickly pear (Opuntia engelmannii).

They also occur in forests at higher elevations. The photo above illustrates this fact, with a handsome rosette situated amidst the single-leaf pinon (Pinus monophylla) and Utah juniper (Juniperus osteosperma) woodland, which thrives at these higher elevations of about 6600 feet (2000 meters). All of these habitat preferences mean that this is a fairly cold-hardy agave that also tolerates wetness in winter. Snowfall is annual in most of its middle and upper range, sometimes staying around for weeks on northern slopes, and temperatures can drop as low as 0 degrees F (-18 C). If you are an agave lover who wants to garden with them in a USDA Zone 7 to 8 climate then this species should be on your list to grow.

Close-up of the rosette of the plant above in the P-J forest at the crest of the Hualapai Mountain Range. It too is a very nice-looking, architectural plant with highlights of red on the uppermost leaf tips.

As with all seed-grown plants, there is genetic variability between individuals. These McKelvey agaves are fairly green, have less bud imprinting, and smaller teeth than the one posted above. Growing in the same general region underneath pine trees as the other, it too would be significantly cold hardy. Plus as a bonus, it produces many more pups than the handsome loner above does. 😉

A yellow form of the desert mariposa lily (Calochortus kennedyi) grows near an agave. Usually brilliant orange, here the lily had occasional bright golden morphs that were mixed in with the typical form. Again, this highlights the role of sexual reproduction in maintaining genetic diversity.

Dropping back down to the upper desert zones and away from the montane regions in the pines, here is Agave mckelveyana growing beneath a California juniper (Juniperus californica). This coniferous tree is mainly a Mojave desert species from the state whose name it bears, although again, in this transitional zone some populations extend into the taller mountains of the northwestern Sonoran Desert in Arizona.

Wider scale view showing the landscape and the mixed Sonoran/Mojave vegetation upon it. The agave combines with the aforementioned Joshua trees, saguaros, hedgehogs, chollas, and junipers as well as with banana yucca (Yucca baccata), desert nolina (Nolina bigelovii), and many more. Overall botanical diversity is high here with at least 350 to 400 different species of plants found within a few miles of this position.

Colorful lichens of several species encrust the northern, shadier faces of the rocks as the agaves cluster underneath the protective cover of banana yuccas and junipers.

As I hinted at earlier, these are rather modestly-sized agaves, with most mature rosettes topping out at between 18 and 24 inches across (50 to 60 cm). The mother rosette has bloomed out and died, while replacement pups jockey for space underneath a cattle-browsed desert nolina.

Taking the agave road show over to captivity, the next photo series features Agave mckelveyana as seen in bloom via cultivated plants in my gardens. I collected seeds of these in Hualapai Mountain Park near Kingman back in 1998, and sowed them in 1999 upon moving here to Yucca.

The plants grew well in my nursery at the rental home in town where I lived for 13 years before transitioning to living full time at D:F Ranch in 2012. After that second move out here, I transplanted all of the agaves I had sown out to the gardens, where most established pretty quickly and survived. The other prominent plants shown here are the white sprays of soaptree yucca (Yucca elata) and the sturdy Spanish dagger shape of Faxon yucca (Yucca faxoniana). The flower photos were all taken in June 2017 when about 19 agaves bloomed in my gardens, 5 of them being A. mckelveyana.

One thing about agaves is that a bare-root move when they are semi-mature can force them into bloom sooner than they might have done otherwise, had they not been disturbed. The root trauma inflicted upon them can stress them to the point where they sense having had a brush with near death, and decide just after they semi-recover that they should flower quickly and reproduce before that can happen again. (The non-flowering foreground plant is Agave palmeri, also grown from the 1998 seed batch and moved at the same time in 2012.)

If moved agave rosettes are at least 65% of their full mature size, many bare-rooted agaves will bolt into bloom just as soon as they are able to, often only  1 to 3 years after their transplanting. Potted agaves whose roots are not disturbed this way are much less prone to premature bolting. The middle flower spike is of A. mckelveyana, and the left and right both belong to A. chrysantha, which again, are part of the 1998/2012 seed batch transplants.

Unfortunately, agaves are monocarpic and bloom just once in their lives before dying, so this premature floral display is the end of the line for them. This stress-induced “desperation flowering” also occurs in other bare-rooted succulents, but since they don’t die after one bloom they usually continue on to recover and grow for many more years. It’s a thought worth maintaining when you are considering moving a mostly mature agave, as to whether the likelihood of early flowering and the subsequent demise is worthwhile. Above, at least 8 different agave flower spikes are visible in June 2017, of three species. The most prominent up front to the right is Agave chrysantha.

Agave mckelveyana flower spikes are paniculate and rather sparse and slender, especially when compared to the robust sturdy spikes of plants like Agave palmeri and Agave parryi. This is a diagnostic feature of plants that overlap in habitat with other agave species.

A. mckelveyana will possibly bloom in the wild at an age of 15 to 20 years as well, depending of course upon habitat conditions such as sun exposure and rainfall. So it may have been inevitable that these recently-moved rosettes were going to flower anyway.

One more view of the gardens at D:F Ranch in June 2017, showing at least six concurrently blooming spikes.

This wild Agave mckelveyana has managed to evade detection and consumption in the emergent “asparagus” stage of the flower spike several months earlier. Many Arizona agaves live in habitat that is today grazed by cattle, and while the cows show no interest in the tough and rigid leaves armed with vicious terminal spines and hooked marginal teeth, the flower spikes themselves are extremely vulnerable to being eaten by hungry bovines. Since agaves are monocarpic, this can seriously impact their ecological health and population abundance.

Agaves that are entirely reliant upon seed reproduction can suffer severe population crashes within only 20 to 30 years under heavy livestock grazing due to lack of seed production, leading to low replacement levels. Agaves that pup suffer less since there are clones to take over where the mother rosettes died, although in the long run a lack of genetic exchange that happens via seed could be an issue. Most Arizona agaves are capable of setting at least a few pups, some more so than others, and as a result the state’s 22 species and subspecies are not quite as insecure as certain Mexican species that don’t have this advantage.

I’ll close with this parting shot of the ultra-handsome Agave mckelveyana I started off with. I hope this post will give readers a good introduction to this horticulture-worthy species that is little known even within agave enthusiast circles.