It's not too late

Could you use some good news? Here’s some: last Thanksgiving the population of Western monarch butterflies counted in California increased by over 100-fold, from fewer than 2,000 butterflies counted in 2020 to 247,237 in 2021. 

 

Monarchs roosting for the winter

That’s not full recovery. Some experts estimate we’ve lost 80 percent of monarchs in 20 years. But it’s nice to know how resilient these butterflies can be.

    Western monarchs are genetically indistinguishable from the Eastern kind. It’s just that monarchs that live west of the Rockies overwinter in California and migrate to the Northwest for the summer. The ones that live east of the Rockies overwinter in central Mexico in the Monarch Butterfly Biosphere Reserve. Around this time of year, as the weather warms, they start their flight to Texas.

 

During the spring three or more successive generations of monarchs journey through the Southeast to the northern states and southern Canada where they spend the summer. Then in August and September another new generation starts to flutter all the way back to Mexico, a journey that takes up to two months (this Google Earth video illustrates it all). 

    Migration is necessary because monarchs can’t survive northern winters. In the mild, humid winter climate of Mexico’s Sierra Madre mountains, they roost in oyamel fir trees (here’s another fascinating video), packing together to stay warm. 

     With this successful life cycle evolved over the millennia, why did the monarchs suddenly start to disappear? The first obvious culprit was glyphosate (Roundup) sprayed on agricultural fields. Glyphosate use surged in the 1990s with the introduction of genetically modified Roundup Ready crops that resist the herbicide spray while it kills the weeds around them. 

Monarch caterpillars need to eat milkweed to survive. Milkweed toxins ingested by monarchs make them poisonous to predators but don't hurt the monarchs.

     Some of those weeds/wildflowers are native milkweeds. Monarchs need to lay their eggs on milkweeds to reproduce. Instead of finding milkweeds offering nectar and forage for their caterpillars alongside every field, the migrating butterflies now had to cross vast milkweed deserts in agricultural regions of the U.S.

Eastern native swamp milkweed is easy to grow and provides a lifeline for monarchs

     A recent meta-analysis by a team at Michigan State University, using data from thousands of volunteer monarch counts, found that glyphosate, habitat loss, and climate change have all contributed to the monarchs’ decline. In recent years, hotter weather in their northern range seems to have been a major factor.

     When we hear that climate change is the reason that species are dying out, it can sound hopeless. We’re not moving fast enough to save ourselves; how are we going to save the monarchs? But as the scientists point out, when migrating monarchs are stressed by high temperatures, that’s when they especially need lots of milkweeds and other native flowers for nectar along their path so they can stop off and refuel or lay eggs.

 

Migrating monarchs need other flowers too for energy from nectar

 
     The surge in Western monarchs shows that the monarch population has the capacity to rebound suddenly and dramatically. And the fact that thousands of human well-wishers are already helping encourages me too. This year let’s redouble our efforts to plant for native insects, and let’s be sure to include milkweeds in the mix.

 

Common milkweed is another good choice. It's a spreader.

 

Ecological gardening

 While snow blankets the garden, it’s all potential. Dreaming of spring, I’m enjoying reading about ecological gardening—what I’ve been calling sustainable gardening, but I like the new term better. As Kelly Norris writes in a recent article in Fine Gardening, ecological gardening means understanding plants as part of a community, not just building blocks for an aesthetic composition.

 

Native Joe Pye weed in an ecological garden

    Goals I currently aspire to achieve in my ecological garden include promoting and supporting biodiversity, helping to keep air and water clean, sequestering carbon, minimizing my garden’s carbon footprint, conserving water, and preventing stormwater runoff. Since these are inherent functions of natural systems, the good news is that gardening this way should be less work, not more.

 

Leaf mulch conserves soil moisture and provides shelter for native insects

 
    Native Plant Trust and the Woodwell Climate Research Center have been researching how these goals can be accomplished in suburban yards in their Yard Futures Project. They’ve chosen yards in six cities: Boston, Baltimore, Minneapolis-St. Paul, Phoenix, Los Angeles, and Miami. The lucky chosen ones get a visit from a team that’s prepared to observe and document what’s living on their property, from birds to insects to soil organisms. The goal of the research is to document the current state of backyards in a range of climate conditions and discover how suburban properties can best support a healthy environment.

    I wish my yard had been chosen! I’d love to know what experts could find there. In one visit, they could detect and document far more than I ever will. But I’m hopeful that my yard would show lots of biodiversity, because I’ve been trying to put out the welcome mat with native plants and gardening strategies that imitate natural processes.

 

Virginia bluebells

    To take it up a notch, I can start to think more about how plants weave together in natural settings. For example, when choosing a perennial, I pay attention to whether it’s a spreader. That might be a red flag for a traditional garden, but for creating a ground cover layer in a naturalistic ecological garden, it can be an asset. But I don’t usually ask whether a plant is tap-rooted or rhizomatous, grows singularly or in colonies, is short- or long-lived.

 
     In nature, plants fill every available space, above ground and below, gaining from each other’s contributions and maximizing diversity. Instead of fields of mulch punctuated with separated plants, ecological gardens are a mix of tall and short, broad and upright, early and late-developing plants, similar to what you’d see in a wild setting.

 

Plants knit together in an ecological garden

    This doesn’t have to look like a mess. By maintaining clear edges and growing large swathes of species that flourish in site conditions, ecological gardeners are creating gardens that are “legible”—appealing to viewers as designed spaces.

    So for this spring and summer, I’m thinking about how to fill up beds with more—more low spreaders, more early bloomers for the first pollinators of the year, more self-seeders. They should be native plants, but that’s not all. They should contribute actively to the plant community.

 

For the pollinators