I spend A LOT of time at a nearby native plant nursery. (Let’s just say that they love to see my car pull up! ) it’s not just a great place to buy plants, but it’s also a great place to learn about natives from the experts. The staff are knowledgeable, enthusiastic and remarkably patient with those of us who are learning. I didn’t realize how patient they were until I overheard this exchange.
It was the end of a perfect spring day, the kind of day when garden center workers have no rest breaks the entire day. Just as things were winding down, a middle-aged woman wandered in looking totally confused. Walking up to one of the staff, she asked, “where’s the milkweed?” When he replied with “which variety?” She gave him a withering look and responded in what can only be described as the you’re a village idiot voice, “ The one those butterflies like, of course.”
Without missing a beat or changing his tone, he explained that Asclepias tuberosa was not ready for sale but she could put her name on the waitlist. Needless to say, that didn’t suit her; she promptly turned and left.
My immediate response to the scene had been to chuckle at her misplaced attitude, but when I stopped and thought about it, I realized that I had just witnessed a sad outcome of the campaign to rescue Monarch butterflies from the threat of extinction. The woman was able to associate a particular butterfly— a monarch — with a particular plant— butterfly milkweed. A good start, but so lacking in important detail.
She had no idea that there are over 100 species of milkweed native to the United States and that 30 of them are regularly used as host plants for Monarchs. Co-evolving over thousands of years, the relationship between Monarch butterflies and milkweed is a unique one. 
Monarch butterflies only lay their eggs on milkweed plants and monarch caterpillars only eat the leaves of milkweed plants. Milkweed plants produce either an opaque or clear latex substance that contains poisonous compounds called cardiac glycosides. While most other animals and insects find this substance to be highly toxic, monarch caterpillars have, over time, developed a resistance to it themselves, but when they ingest it, it becomes a chemical defense against potential predators. In turn, milkweed plants show strong, quick regrowth after monarchs nibble on them.
The familiar butterfly milkweed, or Asclepias tuberosa, has been touted as the preferred species because it is easily grown and readily available in most regions of the country. Its fluorescent blooms in shades from bright orange to soft lemon enliven the garden for humans while attracting the attention of many visiting butterflies –everything from the at-risk monarchs to swooping swallowtails and dainty skippers. It’s a perfect introduction to the milkweed family, but not a stopping point.
No matter where you call home, there is at least one – and probably several – native milkweed species that are just as important to Monarch butterflies as the well-publicized tuberosa. We’ve rounded up information for you on eight that are definitely worth knowing about. To learn about them, just click here to see the powerpoint.
These are just 8 of the numerous species of milkweed that have a special relationship with monarchs. A trip to your local native plant nursery will undoubtedly unearth others. It’s crucial in the fight to rescue monarchs that you get to know them and that you include them in your gardens. To meet the needs of monarchs all season long, try planting at least three different local varieties of milkweed with varying bloom periods. That way, no matter when the monarchs visit your garden, it will be a welcoming place. It’s the least we can do for them!
