Monarchs & Milkweed

The Milkweed bloomed this past week here on the Currant Farm. Milkweed is the common name for the genus of plants called Asclepias named after the Greek god of medicine and healing. The many beautiful Milkweed varieties have been used over the ages for everything from salves and infusions to treat swelling, rashes, coughs, fevers, asthma, female problems and even seasoning added to dishes for flavor or to thicken soups but since there are some toxic issues with regards to the cardiac glycoside content, I recommend leaving it to the experts and butterflies.

The real value of milkweed for me and should be for anyone concerned with nature and beauty is that this group over 100 species of plants is the exclusive host for the caterpillar stage of the monarch butterfly. As the monarch larva consumes the milkweed leaves, it also retains the cardiac glycosides making the monarch toxic to predators. The iconic monarch butterfly is probably the most recognized of all butterflies in North America. Its trademark orange, black, and white wings, while beautiful to the human eye, is a warning sign to predators that this delicate, colorful creature is poisonous to all those on the hunt for the next meal.

The truly amazing thing about the monarch is its life cycle. While it populates all areas of North America in the summer, most of them spend winters roosting in a relatively small area in the Sierra Nevada Mountains in Mexico. Imagine for a moment this gossamer creature, weighing 1/4 ounce, the weight of a few postage stamps, negotiating winds, storms and whatever else nature throws at her, travels between 50 and 100 miles each day to journey 3,000 miles to their winter home. But that’s not even the unbelievable part.

The monarchs, returning from Mexico in the spring, will breed as soon as they find the first milkweed plants. They lay their eggs on the plants so that the larvae, what we call the caterpillar, will have a ready source of food when they hatch. The parents die shortly after. This new generation, with the nutrition of the milkweed, will complete the miracle of metamorphosis, from egg to caterpillar to pupa to butterfly and then continue the trip north following the blooming milkweed. This 2nd generation, just a few weeks later, then breeds when they find a more northly variety of milkweed upon which to lay eggs and the cycle begins all over again with the resulting adults continuing the journey north. They go through up to 4 generations, the first three of which live only 2-6 weeks each. At the end of the summer, when the last generation completes its cycle, the adults somehow know there will be no more milkweed for that year. So instead of breeding, as their parents and grandparents did and with the ability to now live up to nine months, they turn around and somehow know to head back, 3,000 miles to the exact small area in the mountains of Mexico that their great, great grandparents left 6 months prior. Entomologists believe the butterflies have chemicals in their tiny brains which enable them to navigate using the sun but no one knows how they have this “sense memory” to return to the exact spot their great, great grandparents came from every year.  

There has been great concern in past years about the apparent dwindling populations of monarchs returning each year. This may well be linked to climate change and the reduction of their single food source, milkweed. Each one of you can do your little part to help this amazing insect by planting milkweed in your gardens and vacant fields (with permission). There are varieties suitable to all parts of the country and seeds are available online, your local nursery or you can simply collect the seed pods from local milkweed when they begin to open.  In addition to the monarchs, honey bees, other pollinators, hummingbirds and many songbirds love the milkweed too. In fact, milkweed will add to your own little ecosystem.

 One need only be a casual observer of nature to stand in awe of the mysteries and complexities of life. The burdens of conceit and hubris tend to melt away with a minimum of curiosity and investigation. I am, every day, humbled in the presence of the uncountable inhabitants and their myriad intricacies which are the heartbeat of this little farm.

Cheers from the Currant Farm,