One of the most special things I’d always hoped to do was follow the monarch butterflies to Mexico, where they winter. Peter and I just returned from this amazing experience, and I am eager to share it with you.
Monarchs have an unusual life cycle. There are five generations a year, hatched from the eggs left behind after their mother flutters away. First comes the voracious caterpillar, brilliantly banded with yellow, black and white, that eats only milkweed leaves. Ingesting toxins from these plants, the caterpillar is poisonous to predators, and the bright coloration is a warning sign to birds not to eat them. There is some confusion about whether the monarch mimics the viceroy, another orange and black butterfly, or vice versa. Whatever: they all taste bad!
After several molts and instars, the caterpillar does the ‘turn into a butterfly’ trick after pupating in a sage green chrysalis. The northern generations all live about one month, lay eggs and die. The migratory generation lives much longer, spending two months in migration south, the winter in California or Mexico, and one month on the return trip. Not all monarchs migrate. The resident adults found in the Gulf Coast states may never move beyond the garden where they are born and are considered a distinct sub-species. It is not clear how or why they differ, but some of them just never got their invitations to the winter party in Michoacán.
We arrived in Mexico City, drove out of the basin and over two mountain ranges and valleys. The scenery was marvelous, with a snowy volcano peak on the horizon most of the way. We were lucky enough to spend time with Diane Kennedy, the queen of ethnobotanical cuisine. Early the next morning, we arrived at the butterfly reservation. The air was just warming and the monarchs were beginning to flutter away from the tight colonies they form at night. Soon, in the embrace of a bright winter sun, the air filled with millions—yes, millions—of orange monarchs. Swept from the path by colorfully dressed, elderly Mexican women, the population was so thick it was hard to walk without crushing them. They landed on our heads and shoulders, our packs and gear, the rails, the stairs. We were immersed in monarchs. It is an incredible feeling.
Threats to the monarch overwintering sites are serious. Growing populations of humans and deforestation around (and illegally within) the reservations are reducing the conifer groves that provide the adults with winter shelter. On our trip, the road just below the reserve had been washed out in a catastrophic storm. Dozens of people were killed within yards of the reserve when their houses were destroyed. The direct cause of this flooding is clear-cutting of timber. Rain falling on trees is normally slowed by the foliage, and soil is held in place by the root systems. Strip the trees away, pack the soil down with cattle and there is nothing left to prevent the torrents from rushing into the valleys and villages below.
The Monarchs Need You
What can you do locally to ease the pressures on this special species? PLANT A BUTTERFLY GARDEN! We have a few tips, but the Missouri Botanical Garden, including the Sophia M. Sachs Butterfly House and the Shaw Nature Reserve, offers many classes in butterfly gardening and other environmental subjects. See mobot.org/classes.
It seems that butterflies should have simple needs: food, water, shelter from storm and the right place to lay eggs, but they have evolved to have much more complicated requirements. The magnificent orange and black female monarch will lay its eggs only on plants of the milkweed family, and only one egg per leaf, no clusters. If you want to attract them, you must have the proper host plants. The Shaw Nature Reserve, with carefully managed ecosystems, draws more than 83 different kinds of butterflies in the warmer months.
Nourishing Nectar in Your Garden
Buddleia is probably one of the best known nectar plants, such a mainstay of the butterfly garden that its common name is ‘butterfly bush.’ Extremely popular with butterflies as a summer food source, it is a favorite of gardeners, too, as it is easy to grow, not picky about location and blooms prolifically. Unfortunately, it also seeds prolifically and, in some parts of the country, has become a serious noxious invasive weed. Keep up with your deadheading to prevent seed formation and increased flowering.
Two more butterfly favorites are seven-son flower and buttonbush. Seven-son flower (Heptacodium miconioides) matures into a small, multi-stemmed tree resembling crape myrtle. It has wonderful bark texture and loose clusters of small white flowers in August and September, just in time for the south-bound monarchs. Buttonbush (Cephalanthus occidentalis) blooms earlier, with heavy flowering in June and sporadic clusters through July and August. The flowers are round, ping pong ball-sized white globes and very fragrant. A deciduous shrub, buttonbush is an excellent choice for water’s edge or a wet spot in the yard. It has shiny green leaves in summer and few if any pest problems.
Other favorite nectar plants include annuals like salvia, weeping or older varieties of lantana and Julie’s favorite, annual milkweed (Asclepias currasavica). For perennials, try echinacea, liatris, agastache, sedums (especially the old fashioned ‘Live Forever’ type, S. spectabilis), Joe Pye weed, rudbeckia, aster and penstemon. With any of these perennials, as with some of the annuals above, the closer the selection is to the wild species, the more the butterflies will use them. Apparently, the aggressive plant breeding that takes place to provide the rainbow of colors we now get in plants like echinacea and sedum has bred some of the tastiness out of them.
For another butterfly treat, head to the Sophia M. Sachs Butterfly House at Faust Park in Chesterfield for March Morpho Mania™. This flutter-by extravaganza features a massive hatch of the striking, brilliant blue tropical morpho butterfly (Morpho peleides), with its giant, graceful, iridescent indigo wings. It runs until the end of March (9 a.m. to 4 p.m., Tuesdays through Sundays). For information, call 636-530-0076 or visit butterflyhouse.org.