Agaves

Of all the strange spiky botanical forms thriving in the Sonoran desert, some of the most spectacular and extravagant are the agaves. Flowering stalks of agaves begin to emerge as the weather warms in spring, and depending on the species, may grow to over twenty feet tall!   Their reproductive strategy is known colloquially as "boom and bust" reproduction, because the plant will live for many years as a leafy rosette, and then shoot up a stalk bearing hundreds or thousands of flowers in one season. The plant uses so much energy in the process that it dies after the seeds have ripened. The academic term for this is "monocarpic perennial," which translates to "a plant that lives for many years but only produces seeds once." Although agaves are sometimes called “century plants,” most species only live between 20-30 years.

Several years ago, I measured the daily growth of a few specimens in our neighborhood. My records show that agave flowering stalks will grow anywhere between 3 and 9 inches per day for one species I was tracking, Murphey’s Agave.  Murphey’s is one of several dozen types of agave found growing in the Phoenix area, thanks to a bustling import and cultivation business for use in ornamental landscaping. There are actually no wild agave populations within the metropolitan region, although several species grow naturally at higher elevations in surrounding mountains. However, there are a few small populations of Murphey’s, also known as Hohokam Agave, that appear to be remnants of pre-Columbian agricultural settlements. Agave has been, and continues to be, one of the most important utilitarian and food plants for indigenous cultures throughout the Sonoran desert.

Trade between ancient cultures played a large role in distributing agave to new areas far beyond their natural range. Many populations now known between central Arizona and Grand Canyon appear to be what is left of small plantations that were created to harvest for food, medicine and fiber. Both the piña and stalk of some species were roasted and eaten; the large stone-lined roasting pits remain as some of the most visible archaeological features of some pre-historic settlements.  The pulp and juice were also considered to be excellent tonics and healing medicine. Stalks were used as tools, building material and musical instruments. Fiber from the leaves was used to make sandals, fabric and nets. Be forewarned: the sap of some species is so toxic that it could be used as fish poison or arrow poison for hunting.  As noted by historian William H. Prescott in 1843: “The agave, in short, was meat, drink, clothing, and writing materials for the Aztec. Surely, never did Nature enclose in so compact a form so many of the elements of human comfort and civilization!”

Today, huge agave plantations are an important part of the North American economy. Tequila, mescal, agave syrup, and sisal are some of the major products exported from Mexico all around the world. Harvesting agaves is highly regarded as a technical skill, requiring strength and knowledge to recognize and properly cut the mature plants.  Harvesters, called jimadores, use specially designed cutting tools, called coas, to expertly remove the spine-tipped leaves and extract the piña, or core of the plant. Certain species are raised specifically for the fiber in leaves, which is used to produce everything from rope to place mats. Other species are best for the sweet sap that can either be pressed out and fermented to brew tequila, or reduced to make honey-like syrup. Industrial researchers are currently investigating the use of agave to produce bio-fuels. 

Despite the stunning effort put into seed production, very few of the tens of thousands of seeds made by a single agave actually germinate and grow into mature plants. For many species, most reproduction is from plantlets that emerge either on the stalk, called bulbils, or from the roots of the parent plant, called “pups” or hijos (Spanish for “sons”).  These smaller plants are the form that has been most easily traded for thousands of years, and allows us to now enjoy so many kinds of agaves in the suburbs of Phoenix.  Part of the job of an jimadore on an agave plantation is to extract the parent plant without destroying the hijos. Likewise, if you have the privilege of witnessing the flowering and passing of an agave in your home landscape, be sure to collect the hijos and find a good home for them to carry on their line of noble plants. 

Wild Hive

For over eight years, I’ve been visiting a wild hive of honeybees (Apis mellifera scutellata) that I found nestled in a crack in basalt cliffs just a ten-minute walk from our house. The comb is dark and gnarled, with several lobes hanging in layers between the rocks. Bees are constantly zooming in to deliver pollen and nectar, and zooming back out to collect more. Although we are warned that these bees are most likely “Africanized” and thus more aggressive than other breeds, I have never been chased or stung since I’ve been observing this hive. Then again, I have never tried to steal their honey or poke the hive with a stick.  I am also careful not to stand directly in their pathway. Or, maybe they just recognize me as a friendly neighbor whose garden they come down to forage in every day!

These wild bees are the same ones that are at work daily in our neighborhood, gathering nectar and pollen from our landscaping plants. If you have fruit trees and vegetables in your yard, they may be helping you realize a harvest. One way to find out where your garden bees live, is to follow them as they make a “bee-line” back to their hive once they are loaded up. On their way home they will fly the most direct route, in a relatively straight line, to conserve energy.

Local beekeeper, Scott Clark, enjoys the practice of “bee-lining,” which is the art and sport of tracking bees to their hive. “You can tell how many different hives are in an area by watching bees as they leave the plants they are foraging on,” he says. “Sometimes you’ll see several different bee-lines moving to and from a large rosemary plant, which is one of the most abundant nectar producing flowers during winter months in the Phoenix area.”

According to Scott, honeybees will travel up to five miles to find good sources of nectar and pollen, so finding a hive can be a pretty good work out.  This is also something to keep in mind if you are someone who would like to avoid encounters with bees. Mesquites, palo verdes and rosemary are some favorites for desert honeybees, so if you plant them in your yard, you’re sending an invitation to the local hives for five miles around.

If you are someone who appreciates bees and all the products and services they provide, having them visit your garden can be a great source of entertainment. “Bees have a kind of intelligence beyond other insects,” observes Scott, who became addicted to beekeeping at the age of twelve. “They work together, they communicate with each other, and they even argue with each other about the best place to build a hive!”

A few requirements for a wild hive include great foraging nearby, a reliable source of water, protection from predators, and shelter from wind and weather. All of these things make high vertical crevices in cliffs near irrigated landscapes in the suburbs the “bee’s knees” for a honeybee queen and her brood.  These traits are also why buildings sometimes seem like excellent sites for wild hives.  Unfortunately for the bees, most humans don’t like them living in their houses, so that is not usually a great choice!

For lots more info on honeybees, or resources to remove troublesome swarms and hives check out any of these websites. An experienced beekeeper will always do their best to remove the bees alive and help them find a safe home away from yours!

Beekeeper Scott Clark of Cave Creek www.beesvillebeefarm.com

Beekeepers Association of Central Arizona www.azbaca.org

Swarm removal for every state www.bees-on-the-net.com

Desert Queen

If you look carefully, even in the depths of what we call winter here in Phoenix, you can find several stages of the Queen Butterfly, and maybe all four! The best place to search is on a milkweed plant, which is where eggs are laid, caterpillars munch, and chrysalises are formed.

Queen butterflies usually lay their eggs on milkweeds so that when the caterpillar hatches out, its favorite food is right beneath its feet. Desert milkweed is commonly planted in suburban gardens and commercial landscaping, although it is native to areas further south and west. Twining milkweed grows wild along washes or in irrigated areas where it climbs trees, shrubs and fences. Finding butterfly eggs on a milkweed takes a lot of patience, but if you look carefully under the leaves or on the stems, you may find what looks like tiny round pale green or white beads. This is where the magic of metamorphosis begins.

When the eggs hatch, the caterpillar gets to work doing what it does best: eating. Like the Queen’s better-known look-alike, the Monarch butterfly, milkweed sap that is eaten by the caterpillars renders both the larval and adult butterfly poisonous to any bird or other critter that might try to eat them. Potential predators quickly learn to avoid eating black-and-white striped larvae with yellow spots or the equally toxic orange and black butterflies.

Both Monarchs and Queens have orange wings with black edges and white spots, but the Monarch has darker black and brighter orange, and is a bit larger. Queens are more of a rusty orange and much more common in the Phoenix area. Queens also stay in the area year round, unlike Monarchs, which are famous for annual migrations to and from warmer winter climates where they form huge colonies resting in trees. You can easily tell a male from a female in both species by the small black patches on the inside edge of the males’ wings that release a scent to attract females. (This makes me wonder: Should a male Queen be called a “King” butterfly?)

Of all the butterfly stages, the jewel like chrysalis is the most magical to me. The smooth porcelain white shell is gilded with gold spots, and hangs by a thin stalk from the milkweed plant where the caterpillar came to rest. My son and I found a chrysalis gleaming in the sun on our morning walk to school one day last spring. Looking more closely, we found a caterpillar quietly resting, and then a butterfly landed to sip nectar from the milkweed flowers. We didn't find any eggs, but seeing the other three stages all on one plant intrigued Orion so much that he sat down on the sidewalk and watched for a long time. After a while, he got up and exclaimed, "Nature sure is amazing! Wait till I tell the kids at school about this!"

You can invite Queens and other butterflies into your home garden. The key is to grow wildflowers and shrubs that are the host plant, or species that the butterflies will lay their eggs on and caterpillars need to eat. This also means that when you see a caterpillar chowing down on your plants, you need to let it be so that it will mature and transform into a chrysalis. For Queens and Monarchs, you’ll definitely need milkweeds, which are available at many local nurseries.

If you find a caterpillar, and want to watch it grow and turn into a butterfly, be sure to gather and feed it leaves and stems of the plant you found it on. When the butterfly emerges from a chrysalis, be sure to give it plenty of time and room to spread its wings, then let it go free!

To learn more about our local butterflies, butterfly gardening and information about butterfly hikes with experts, check out the Central Arizona Butterfly Association (CAZBA) website at www.cazba.org.

Ringtails: Arizona's State Mammal

Nimble and clever, with a striped tail the length of its body, the ringtail was declared Arizona’s state mammal in 1986, heralded along with the cactus wren (the state bird), giant saguaro (the state flower) and ridge-nosed rattlesnake (the state reptile) as a distinctive member of our natural landscape. Because they are nocturnal, few people ever see these creatures in the wild, although you may hear them rummaging around for food or catch their eyeshine in a flashlight if you happen to be camping out in ringtail territory.

A long, lithe body and banded tail must be very useful traits, since several other species with these features have evolved in other parts of the world. The ringtail is sometimes confused with the band-tailed lemur, a native to the island of Madagascar off the southeastern coast of Africa. Lemurs are primates and thus more closely related to humans than to ringtails. Another look-alike is the civet, a southeast Asian animal popularly known for its musk, which has been used in formulas for expensive perfumes, including Chanel No. 5.


Although not closely related to either lemurs or civets, ringtails are close cousins to two other critters with black-and-white tails that live in Arizona, raccoons and coatimundis. How to tell the difference? Raccoons and coatis are both much larger than a ringtail; a large raccoon or coati can be up to 15 pounds, whereas an adult ringtail is rarely more than 3 pounds. Coatis have a long pointed snout, and usually travel in small groups during the day; both raccoons and ringtails are nocturnal and mostly solitary. Raccoons have a black mask, whereas ringtails have big, dark eyes rimmed with white eyebrows. Ringtails are slender, like a ferret or weasel, and about one and a half feet long; half of that length is their magnificent bushy tail. Fortunately for them, their fur is not luxurious enough to be highly valued, nor are they considered pests, so ringtails are rarely trapped or hunted intentionally.

Their Latin name, Bassariscus astutus, means “clever little fox.” Sometimes they are called miner’s cats, harkening back to the days when miners kept them as pets to keep camps pest free, since ringtails feed on mice, insects and lizards. Ringtails are neither fox nor cat, which adds to the confusion about these seldom seen animals. They are common throughout the desert southwest of the United States and Mexico, as well as agricultural areas and scrub forests of higher elevations. They have adapted well to urban life also: the resident ringtail at Adobe Mountain Wildlife Center in north Phoenix, named Ringo, was captured in the attic of a nearby shopping center, where he slept during the day, and scavenged for food in the store during the night!

You can learn more about ringtails and other native wildlife at the Adobe Mountain Wildlife Center. For information about volunteer opportunities, events, education and wildlife sponsorship, visit their website: www.azwildlifecenter.net

Black Widow Refuge

Our back yard is a refuge for black widow spiders. Perhaps it was the famous storybook character, Charlotte, who convinced me that spiders deserve to be allowed their quiet livelihood in our yard. Or maybe it’s my over-developed ecological sensibilities that respect the necessary role that spiders play in nature, even in the suburbs. Rather than spraying our home regularly with pesticides, we've chosen to let these eight-legged, venomous predators live in our yard, where they weave webs, lay eggs and provide food for the numerous lizards and birds that also visit. Whenever I see a gleaming black widow with slender legs and red violin tattoo on her belly, I am fascinated rather than repulsed.

This may seem reckless or foolish to most people, but so far, these quiet, nocturnal creatures have obliged by keeping out of sight during the day, and sinking their tiny fangs only into edible prey, such as crickets and grasshoppers that also enjoy refuge here. Once in awhile I'll see one resting on its tangled web in a potted plant on the patio at night, but as soon as she senses my presence, the spider scurries out of sight, knowing rightly that I am far more dangerous to her than she is to me.

Out in the log pile, I reach in with gloved hands to gather wood for a new moon fire, setting aside the marble sized egg sacs full of soon-to-be spiderlings. Each of those little sacs may contain more than 750 eggs; one black widow can build half a dozen sacs in a summer. The idea that nearly 5000 spiders will soon be crawling around in my back yard is a bit daunting, but in reality, only a dozen might survive to become adults. The rest are eaten by each other or by the birds and lizards that abound in our refuge.

Sticky masses of black widow cobweb are a minor nuisance to me, but not to the hummingbirds that buzz in to gather this critical nest-building material. Without an abundant supply of ultra-strong and resilient spider web, a hummingbird nest cannot be bound to a branch or hold together well enough to protect the jellybean-sized eggs that will be laid in the down-lined cup. After the eggs hatch, baby spiders are excellent food for the young hummers. This is where the web-of-life becomes quite literal! For two years we have enjoyed watching baby hummingbirds grow and fledge from nests in our back yard refuge.

So far, we have not experienced any grotesque infestations of roaches, ants, crickets, spiders or scorpions, some of the "pests" that support a thriving chemical industry in Arizona. (However, I will admit that when the termites start drilling into our walls, I call the exterminators.) Yes, all of these creatures are here in our refuge, but as long as they stay outside in the back yard, we coexist peacefully. I like it that way.

That Tropical Feeling: Palms in the Desert

Living in the Sonoran desert can get a little dry at times, so one way we delude ourselves into feeling like we actually live in a tropical paradise or on the shores of a Caribbean beach is to plant palm trees. Our need for desert denial is so great that, next to the faux saguaro, one of the most common tech art designs for cell towers is a palm. But did you know that there is actually one species of palm that is native to Arizona and the Sonoran Desert?

The Desert Fan Palm (Washingtonia filifera) is a relict of more temperate days in these parts dating to as long as over six million years ago. Today, small wild groves are still tucked up in secluded canyons and near springs in the southwest where they have a reliable source of water. Just north of Phoenix, the privately owned Castle Hot Springs Resort includes natural springs that nurture a palm forest, as well as developed springs and carefully manicured groves. West of Phoenix at the KOFA National Wildlife Refuge, a small wild grove persists high up in a narrow shady canyon. Over in California, you can relax in the shade of native palm oases at Joshua Tree National Park.

Closer to home, all around us in the suburbs of Phoenix, our native palm is one of about two dozen species that have been introduced from all over the world for landscaping. One of the best places to view what most resembles a natural Desert Fan Palm grove is at the Phoenix Zoo, where the palms have developed massive “skirts” of dead fronds that surround the stout trunks. Groves in their natural, unpruned form are habitat for abundant wildlife, including a rare bat species, desert rats, lizards, snakes, many type of insects and birds, bighorn sheep and coyotes. Hooded Orioles use palm fibers to weave beautiful nests that hang in the protective shade of the leaves. For indigenous people, palm groves were a source of fiber that was woven into cloth and twined for cordage, leaves for making thatched roofs, walls and baskets, plus fruit and seeds for food.

Unfortunately, the benefits of palms for wildlife are not so endearing to many contemporary homeowners, who prefer not to welcome so many critters into their yards. Palm skirts are also regarded as a fire hazard, although in wild areas, occasional fire actually rejuvenates the groves by clearing out dense brush and creating fertile ground for new trees. Healthy mature palms are fire resistant, and will usually survive a wildfire.

Other notable palms in the suburbs are the majestic date palms, whose Latin name, Phoenix dactylifera, happens to include the name of our fair city. Date palms differ from fan palms in having long feather-shaped leaves, and also produce sweet succulent fruit. A relict of the commercial groves that were once abundant in the area is ASU’s Polytechnic Campus Date Palm Grove, which boasts over fifty different cultivars and is reputed to be the largest date palm collection of any public garden in the country. These palms represent a rich history of human civilization centered in the Middle East, where palms were critical to the development of early agricultural societies and highly valued for trade. The importance of date palms is recorded in drawings and temples of ancient peoples dating back to 7000 years ago. According to Islamic tradition, the original tree of life in the Garden of Eden is said to have been a date palm.