How To Build The Perfect Monarch Butterfly Garden

monarch on pink flowers

Daniel Potter freely admits he’s not an expert on monarchs. But as a professor of Entomology at the University of Kentucky, he and his grad students sure love to run experiments. Recently, they completed a 2-year study on the likes and dislikes of the popular orange and black butterfly. Now for the first time ever, there’s a roadmap for building the perfect monarch garden.


If you’re reading this post, you’re probably already a monarch fan. The butterflies’ annual migration from Mexico to Canada is one of the most spectacular events worldwide. All told, the tiny insects fly upwards of 2000 miles roundtrip each spring, stopping four times along the way to breed and lay their eggs. They are the only butterfly species to make such a long, two-way migration.

monarch migration

The past 25 years, however, have seen a sharp decline in monarch populations. Part of this is due to loss of habitat at the butterflies’ overwintering site in Mexico. Activities such as logging, agriculture and urbanization have all taken their toll on the central highland forests that play host to the insects six months out of every year.

But by far the most significant factor driving the decline is the dwindling supply of a plant called milkweed. The native wildflower is the only plant that monarch caterpillars will feed on. And without it, the butterflies cannot complete their life cycle, sustain their migration and ultimately, perpetuate their species.

monarch feeding on milkweed


According to the North American Monarch Conservation Plan, we need 1.8 billion milkweed stems to replace those that have been lost to agriculture and urbanization. And these contributions need to come from all land sectors in order to sustain the annual migration. This includes farms, roadsides, schools, zoos, rights of way and yes, suburban and urban gardens located along the butterflies’ migratory corridor.

Luckily, an initiative called the Monarch Waystation Program is starting to make a crucial difference. Established in 2005, it engages citizens in conservation by providing instruction and materials on how to create habitats for monarchs. The guidelines are simple – Plant two or more milkweed species for the caterpillars, some nectar sources for the adults and you become part of a national registry. To date, over 6000 Monarch Waystations in 46 states have become part of the effort. 


And as it turns out, the Waystation Program Registry provided the perfect jumping off point for Potter’s research into monarch butterfly gardens. A quick Google Earth search revealed hundreds of habitats dotted along the butterflies’ northward route. Furthermore, they represented every kind of landscape.

As Potter put it, ‘Some were non-structured, others ‘wild’, and still others were surrounded by hardscape or located in open rural areas.’ Below are some aerial shots of a few of them. (Photo courtesy Dr. Daniel Potter.)

What Potter and his team wondered was this – with all of this diversity, could there be certain habitats that appealed to monarchs more than others? The group decided to survey 22 citizen-planted Waystations in an effort to find out. Their research ended up producing some interesting results. 


Like most species, monarchs use visual cues to zero in on what they’re looking for. And in the butterflies’ case, these ‘search images’ are made up exclusively of milkweed. But as the Registry revealed, not all waystations were the same. Did monarchs favor some monarch butterfly gardens over others?

Monarchs from ‘search images’ for milkweed

To find out, the researchers counted larvae and caterpillars for a year in their target Waystations to see if the type of habitat made any measurable difference.

monarch caterpillar on milkweed leaf

Monarch caterpillar on milkweed leaf

And they discovered that yes, the butterflies had a strong preference. A structured garden, with milkweed set off by mulch, attracted three to five times more monarchs.

The takeaway? If you want more monarchs, make it easy for them to find the milkweed to lay their eggs on. Plant it apart from other plants. Even better, surround it with a mulch circle. But make sure to provide other nectar producing plants nearby for the returning adult butterflies to feed on.


Interestingly, the researchers found that gardens with unimpeded north-south access recruited more monarchs. This makes sense since it coincides with the butterflies’ migratory route.

monarch migration map

Monarchs prefer gardens with a north-south access


While all milkweed species are suitable for food, not all are equally favored by monarchs. To find the answer why, the group compared 8 species of milkweed all grown in Kentucky and native to the area. They evaluated them as to their suitability for egg-laying as well as their usability as food for monarch caterpillars. And there was a clear preference.

Where they had a choice, monarchs preferred the taller varieties, Swamp, Common and Showy over the smaller varieties like Butterfly weed

The takeaway? If you want to attract more egg-laying monarchs to your monarch butterfly garden, plant the tall, broadleaf milkweed species like common, swamp or showy milkweed.


But what about all of the new milkweed cultivars, you ask? As it has grown in popularity (mainly due to monarchs), milkweed now has many cultivars boasting unusual colors and sizes.

Asclepias Gay Butterflies Mix/White Flower Farm

Not to worry. Potter and his students discovered that monarchs find these cultivars just as attractive as the straight species. But again, go with the bigger varieties if you want more monarchs.


Finally, there’s the case of tropical milkweed, a non-native plant that has exploded in popularity over the past decade. Both gardeners and monarchs love it. But buyer beware. Tropical milkweed is not ‘bad’, per se, but when planted in warm areas of the U.S. it encourages monarchs to stick around longer and even enables them to winter-breed.

tropical milkweed

Tropical milkweed, Asclepias curassavica

Research shows, however, that monarchs breeding on tropical milkweed throughout the winter (rather than returning to Mexico) have higher levels of protozoan infection compared to monarchs in the normal migratory cycles. It turns out that migration is key to outrunning these pathogens.

The takeaway? Stick to the tried and true native milkweed species in your monarch butterfly garden and help the insects keep to their schedule.

To learn more about Daniel Potter and his research into monarchs and other insects, click here for the Dr. Daniel A. Potter Laboratory.


The Seed Vault That May One Day Save The World


If our planet ever goes to ruin, it’s good to know there’s a place squirreling away the world’s seeds. Located deep inside a mountain just north of the Arctic Circle, it’s known as the Svalbard Global Seed Vault. Here in an icy chamber, duplicates of close to a million seeds are stored in the largest secure seed storage facility of its kind.


In a world of increasing instability, the Svalbard Global Seed Vault offers the ultimate life insurance policy. Its mission is simple. Designed to safeguard the world’s crops from large-scale natural or man-made disasters, it’s a backup for the global food supply.

We have the Norwegian government and Cary Fowler, executive director of the Global Crop Diversity Trust to thank for the idea. In the early 2000s, they recognized that the world’s gene banks were inherently vulnerable. Given that most of the world’s population depended on agriculture for survival, it seemed prudent to preserve seeds. They hit on Svalbard as the answer.


Situated north of Europe midway between mainland Norway and the North Pole, Svalbard is a Norwegian archipelago in the Arctic Ocean. One of the world’s northernmost inhabited places, the area boasts rugged mountains, fjords and frozen tundra providing refuge to polar bears, reindeer and the Arctic fox.

In the 17th and 18th centuries, the islands served as an international whaling base. But in the early 1900s, they turned mainly to mining coal.  


Polar bears are the iconic symbol of Spitsbergen

Of the four main islands, the largest one is Spitsbergen, which accounts for more than half of the area. Most of the archipelago’s small population lives here in Longyearbyen, a small coal-mining town.

The colorful houses of Spitsbergen’s largest settlement, Longyearbyen 

And just a little over a decade ago, the residents welcomed the Svalbard Global Seed Vault as their new neighbor.

Svalbard was chosen for several reasons. Not only was its remote location ideal, but its Arctic climate and year round frozen ground made it perfect for underground cold storage. Construction of the facility began in June 2006 in an abandoned coal mine deep inside Spitsbergen’s Plateau Mountain. Surrounded by thick rock and permafrost, the completed vault had the capacity to store 4.5 million different crop varieties. 

‘It is the best insulated freezer in the world,’ said Cary Fowler.


Credit: Matthias Heyde


Like many out-of-the-way places, the only visible part of the 10,764 square foot facility is its entrance. Formed out of dark grey concrete, the minimalist lobby juts horizontally out of the mountain. Inside, a massive tube of corrugated steel pipe leads down into the permafrost to three separate but identical chambers.


Credit: Matthias Heyde

According to the Crop Trust, the Svalbard Global Seed Vault currently houses more than 980,000 samples. Originating from almost every country in the world, they include tens of thousands of essential crops such as beans, wheat and rice as well as many unique food varieties. To ensure their survival, each species is stored in boxes behind heavy locked doors in custom, four-ply aluminum packets. 


Credit: Matthias Heyde


So how does it work? It helps to think of the Svalbard Seed Vault in terms of a bank. For example, the vault is owned by the country it’s located in (Norway) and the depositors (global gene banks) own the contents of the boxes. However, seeds are accepted only a few days a year.

Moreover, the seeds are not ‘originals’, but copies of seeds belonging to the depositing gene banks. Anyone who wants access to the seeds, such as plant researchers, farmers or other groups, must request seed samples through the donor gene banks. No one can access the site directly.


Credit: The International Institute of Tropical Agriculture i Nigeria (IITA)

In fact, the state-of-the-art and fully automated seed bank has no permanent staff on site. Instead, the vault is monitored remotely.  Even so, Spitsbergen residents check in on it regularly.


Despite the fact that the seed vault is not open to the public, a piece of art nevertheless embellishes the roof of its lobby. Created by Norwegian artist Dyveke Sanne, it is called ‘Perpetual Repercussion.’ Composed of stainless steel triangles, mirrors and prisms, the unusual piece reflects the Arctic light back out into space in an ever-changing composition.


Credit: Mari Tefre/Svalbard Globale frøhvelv


A feasibility study, undertaken prior to construction, determined that the Svalbard Global Seed Vault could preserve most major crops’ seeds for centuries. And some important grains could survive even longer, possibly for thousands of years.



In 2015, the civil war in Syria prompted the first ever withdrawal from the Svalbard Seed Vault. Researchers took 38,000 seeds out of the vault to replace crops that had been diminished in the conflict. Read about it and view coverage here at 

Construction of the $9 million facility was funded by the Norwegian government. The facility is now managed by the Ministry of Agriculture and Food on behalf of the kingdom of Norway in coordination with the Nordic Gene Resource Center and the Global Crop Diversity Trust. Recently, Norway announced they will spend close to $13 million dollars to upgrade the 10-year-old facility. 

To learn more about the Global Seed Vault and take a virtual tour of the facility visit the Crop Diversity Trust.


The Difference Between Bees, Wasps and Hornets

What’s the difference between bees, wasps and hornets? You may be surprised to learn that some are masquerading as imposters. Take yellow jackets for instance, whose yellow and black stripes speak bee when in fact they are wasps. In the natural world, though, all three serve a purpose. So before you reach for the chemical spray, please see below. Continue reading

5 Ways To Honor Our Planet On Earth Day


It’s been a half century now since Earth Day made its debut on April 22, 1970. I still remember the strangeness of being dismissed early from school to clean up litter. At the time, the idea seemed foreign to us, which means, of course, that we were used to throwing our trash on the ground. It’s hard to imagine in this day and age that was the common mindset. Continue reading

Nurturing Wildlife Habitats: Five Ways To Save the Planet

For many of us, attracting wildlife to our gardens sounds good in theory but fails in practice. Especially when it comes to that four-legged pest the white–tailed deer. However, there are many sound reasons for enticing birds, insects, even small animals back into our yards. It’s not only good for our local ecosystem, but it also keeps our flowers blooming. And it just might be the right thing to do. Continue reading

Seasonal Eating: The Best ‘Warming’ Foods To Try This Winter

cover garlic

Winter has its challenges if, like me, you’re looking for fresh produce. And that makes it hard to resist all those imported fruits and vegetables. Continue reading

Help Save The Monarchs With These 4 Great Milkweeds

Monarch butterfly on swamp milkweed

Last week, I was manning the booth at the Master Gardener Demo Garden when someone plopped a tall, spindly plant down onto the table. It looked pitiful; the flowers were long gone and the leaves had circular holes in them. But upon closer inspection, I spotted a few lantern-shaped chrysalises and some colorful caterpillars working their way up the stems. The plant was none other than milkweed. And the ‘lanterns’ contained baby monarchs in the process of forming. Continue reading

Chernobyl Plants And The Exotic World Of Ruderal Species

“Sometimes the best thing you can do is…. nothing. –Oliver Kellhammer, Ecological Artist 

There’s a lesser-known field of botany called the study of ruderal plants, or plants that grow on waste ground, ruins or rubble. Borne by birds, wind or other animals, the weed-like species are the first to colonize lands disturbed by wildfires, avalanches, construction and other ecological disasters. The plants self-sow in abandoned areas, forming impromptu gardens and forests over time. They’re living proof of what Mother Nature can do when left to her own devices. Continue reading

What Dirty Old Birds Can Teach Us About Air Pollution

Bird specimens at the Field Museum of Chicago

It couldn’t help but attract my attention; a neat row of old, preserved birds, their soft, feathery chests face-up: some were dark with soot, others by comparison, were clean. All came from an industrial area in the United States called the Rust Belt. That is key to the story. Continue reading

Five Reasons Why Trees Fail: A Bartlett Tree Expert Speaks Out

why your trees are failing

Trees are generally admired for their surface beauty, but their health and vigor springs from what’s underground. That’s according to Dr. Kelby Fite, Director of Research for Bartlett Tree Research Lab in Charlotte, NC, who spoke to Maryland’s master gardeners last week on the reasons why trees fail. His lecture entitled ‘Managing the Landscape Below Ground’ provided a wealth of information about how to improve the life of the trees in our landscape. According to Fite, it all starts with the soil. Continue reading