Plant milkweed to help save the monarch butterflies

by Comments (19)

This post may contain affiliate links. If you click on an affiliate link and make a purchase, we receive a small commission at no extra cost to you. Find our full disclosure here.

In 2014, I came across one of the most clever uses of a hashtag I’ve seen on social media: #GotMilkweed. The hashtag was part of a campaign launched by the David Suzuki Foundation that aimed to create a monarch butterfly corridor in Toronto. (For readers who live in the U.S. and abroad, David Suzuki is a prominent scientist and environmentalist here in Canada.)

The statistics are grim. Scientists have been reporting staggeringly low numbers of monarch butterflies that migrated to Mexico, partly due to the eradication of milkweed across North America. The milkweed plant is not only an important food source for monarch caterpillars, it’s the only plant on which a monarch butterfly will lay its eggs. (2016 update: A World Wildlife Fund survey suggests “migratory monarchs are rebounding—but with a long road ahead.”)

In the last couple of years, scientists have been encouraging gardeners to plant milkweed to help the monarch butterfly population. I planted some in my garden and asked wildflower guru Miriam Goldberger, author of Taming Wildflowers (St. Lynn’s Press, 2014) for some advice.

A few tips for purchasing and planting milkweed

“It’s unfortunate that such a beautiful and important plant in our North American ecosystem is named a weed,” says Miriam. Common milkweed (Asclepias syriaca) is the source of the plant’s bad reputation—it’s quite invasive. Here in Canada, it also used to be on the Ministry of Natural Resources’ noxious weeds list.

Common milkweed (image courtesy of Miriam Goldberger)

Common milkweed (image courtesy of Miriam Goldberger)

The good news is there are other types of milkweed that don’t spread. “Monarchs will also enjoy red milkweed (Asclepias incarnata) and butterflyweed (Asclepias tuberosa),” says Miriam. “Both of these are host plants for the adult monarchs as they lay eggs, and as food source hosts for the larvae (caterpillars). These two alternatives do not spread by rhizomes and are employed by monarchs just as often as the common milkweed.”

Miriam says that red milkweed will grow in any soil type, but it prefers medium to moist soils. It likes full sun (though it will tolerate a bit of shade). “Butterflyweed will also tolerate some shade, but is a bit more picky about its soil type, preferring sand or loam. Dry to medium soils are preferred,” she says.


Butterflyweed (image courtesy of Miriam Goldberger)

And, you can still plant common milkweed, says Miriam, especially if you have dry, clay soil. You should plant it with a combination of other native flowers and grasses that take up the various levels of soil, she warns. “Common milkweed spreads by rhizomes (underground runners or roots) which is why it can be such an aggressive spreader. By planting it within a fairly dense planting of other native species, you leave minimal room for the rhizomes to travel.”

Miriam says liatris, goldenrod and asters are other forms of monarch nutrition that you can add to your garden.

Sadly, in the last few years I haven’t seen many monarch butterflies flitting throughout in my garden. I’ve spotted a few other types, especially around my buddleia, but I want to make sure the monarchs find a welcoming spot in my garden, too. I eagerly  spread the #GotMilkweed message so other gardeners could add it to their must-plant lists. “Anything that brings forward the issue of native pollinator health is a good thing,” agreed Miriam, who says the monarch butterfly issue is coming to light, largely due to David Suzuki and his team’s efforts. “He is raising awareness in a way that only David Suzuki can and it’s proving to be a positive step forward.”

Where to buy milkweed

A local native plant sale is a good place to begin your hunt for milkweed. Ask your local nursery manager if the store will be carrying any native varieties this spring. Miriam sells seeds through her Wildflower Farm website. In Nova Scotia, Baldwin Nurseries sells plants. Botanical Interests offers Asclepias speciosa.

Main image (red milkweed) courtesy of Miriam Goldberger

Related Posts

19 Responses to Plant milkweed to help save the monarch butterflies

  1. Ron Mitchell says:

    I’m not sure how much it would help here in Ontario to plant milkweeds when the monarchs aren’t breeding enough on the way north to make it to Ontario. I understand when they are migrating north, they reach the American mid-west and the farmers have sprayed enough to kill their milkweeds so the monarchs can’t reproduce that generation that makes it here.

    • Helen says:

      I am from Parry Sound area and saw Monarch’s near Sudbury, Ontario last summer. (2015) I found wee caterpillars and eggs and put them in a netted area and released 50 adults by September.

      So Monarchs fly up here and do their thing. Please plant milkweed in areas where the municipalities will not mow down and do not let anyone spray anywhere near milkweed or the nectar flowers that we are all going to encourage!!

    • tessa zimmer says:

      Helen is correct, milkweed is essentially all over Ontario -many of us are planting it, watching caterpillars, chrysalises, and butterflies emerge – they then head to Mexico – the caterpillars eat the milkweed, not the butterflies – butterflies sip on the nectar of plants such as golden rod, wild aster, queen anne’s lace, and a wide variety of other flowers – please plant milkweed – thank you.

  2. savvygardening says:

    I think it’s important to spread the word and hopefully some of our readers in the U.S. see this, too. Only good things can come from planting milkweed, so I’m willing to try 🙂 ~ Tara

  3. April Anderson Demes says:

    I haven’t seen a ton of monarchs in my corner of Alberta, but they are around. I’m adding some milkweed to my back pasture this spring. There’s wild bits around the edges where I think it will be happy.

  4. James Russell says:

    Southern Ontario doesn’t sound too promising for milkweed cultivation but I,m going to try.

    • Tara Nolan says:

      Hi James,
      It’s definitely worth a try! Native milkweed is pretty prevalent in Southern Ontario in fields and beside ditches. A plant turned up in my backyard and I didn’t even plant it there! I also planted asclepias tuberosa last year, which has really nice orange flowers and it did well this year! Best of luck!

  5. gardengnome says:

    I’ll be planting both milkweed and butterflyweed.

    I’ve had conversations with several people who are also on board in my city. A coworker was able to get seed pods of native milkweed from a friend, so we’ll be sharing!

    Spreading the word here in northern Indiana, US. 🙂

  6. Monarchs DO migrate through Ontario. You can imagine the surprise and delight my family and I experienced when literally thousands of Monarchs rested in our backyard in Thornhill, Ont. We were one of the few remaining acreages in the highly developed area. Unfortunately, many of them succumbed to the labours of their journey and just dropped to the ground. This occurred about 24 years ago. Maybe there aren’t enough left to migrate through the area now.

  7. Katharine says:

    We’ve had a few on my property in Quebec, just north of Montreal on the edge of the Laurentians. The first sighting was 2014. Like others, my neighbourhood is one of the last remaining areas not highly developed. I’m planting three milkweed (2xAsclepias Incarnate and 1 Asclepius tuberose) this year – it’s all the garden centre had! I’m hoping that is because the word is spreading. My growing season is short here so I will try from seed next year – can anyone recommend a good native seed vendor for Quebec?

  8. Trish says:

    I just watched a documentary on the Monarch and I am planning on adding milkweed to my garden this year.

  9. Elaine says:

    Should I be pulling out 3 to 4 foot common milkweed that is growing in a naturescape at the elementary school I work at. I know that they attract Monarch butterflies and would like to keep them as they look nice but was wondering if they are actually an invasive plant in Alberta. Also we have preschoolers that play there and was wondered inf they are poisonous if ingested. Thanks!

    • Common milkweed is invasive. Pulling the stalks out will help manage it, but they’ll still keep popping up. Despite its invasive nature, it’s a very important plant. I’d pull out only what you have to. Kids are unlikely to eat the plant since the laytex sap is apparently very distasteful.

  10. Lisa Champlain says:

    Inexpensive milkweed from a non profit

Leave a Reply

Your email address will not be published. Required fields are marked *