Wednesday, June 1, 2016

Where to Buy Milkweeds to Grow in Colorado

Colorado, straddling the Rocky Mountains, has, on the eastern side--Front Range--monarch butterflies from the eastern North American population and on the Western Slope, butterflies from the western monarch population. Colorado doesn't fit neatly into the current "Grow Milkweeds for Monarchs!" push because the common milkweed, Asclepias syriaca is not native here.

Monarch caterpillars eat only milkweeds, so reductions in milkweed populations reduce monarch butterfly numbers.
showy milkweed, Asclepias speciosa
a Colorado milkweed
showy milkweed, Asclepias speciosa
Milkweeds are native all across North America--there are 140 species--but that "weed" in their name makes us assume they are ubiquitous. Far from it. Planting milkweeds to help monarch butterflies find it easier to find food for their larvave makes very good sense.

The common milkweed (A. syriaca) doesn't grow in Colorado. Since there are 19 species of milkweed native to Colorado, it only makes sense to grow those. The easiest to grow is the showy milkweed, Asclepias speciosa It is the milkweed you see in Colrado side-lots and roadside ditches. It looks a lot like the common milkweed.

showy milkweed, Asclepias speciosa
showy milkweed, Asclepias speciosa, growing by the Chilson Center, Loveland in 2015
The butterfly milkweed, Asclepias tuberosa, also called butterfly weed and pleurisy root, is native across much of the United States, including Colorado. Colorado is about as dry a place as it grows, so it will do better with a little supplemented water

butterfly milkweed Asclepias tuberosa
butterfly milkweed Asclepias tuberosa
The swamp milkweed, Asclepias incarnata, is found in wet places in Colorado, along streams, ponds and in wetlands. To grow it in a garden, it will need extra water.

swamp milkweed Asclepias incarnata
swamp milkweed Asclepias incarnata

Showy milkweed can be spotted along roads. I know two corners in Loveland where it is growing. You can gather seeds from wild plants in the fall. Check out online sites that describe how to save the seed.  LINK

Or you can buy seeds and plants

A good general source is the Xerces Society's Milkweed Finder page (link). The Xerces Society is committed to invertebrate conservation, including butterflies like the monarch. Their list of sources of seeds is by state so you simply look up Colorado.

As I wrote this (May 30, 2016) they listed the following places as sources for seeds and/or plants for all three recommended milkweeds: showy milkweed, butterfly milkweed and swamp milkweed:

Applewood Seed Company, Arvada
Beauty Beyond Belief Wildflower Seed Company bbbseeds in Boulder (;
Botanical Interests in Broomfield (
High Country Gardens office in Vermont, greenhouse in Denver, (

In all cases, the Xerces Society is careful to say "please inquire about seed origin"  The recent sudden demand for milkweeds means sellers run out. These plants have large ranges: seeds from Georgia might not do well in Denver.

In addition, I found the showy milkweed offered by
Annie's Annuals, Richmond, California They are  selling plants not seeds.

The following were selling butterfly milkweed:
Western Native Seed, Coalville, CO They sell seeds, but they were out of stock on 5/30/16. 
Fort Collins Nursery, Fort Collins 
Fossil Creek Nursery, Fort Collins -  They sell plants: two varieties of butterfly milkweed in stock.
Harlequin Gardens, Boulder -    They sell plants. 
The Tree Farm, Longmont They sell plants from their greenhouse.

The following were selling swamp milkweed:
Fort Collins Nursery, Fort Collins 
Western Native Seed, Coalville, CO  Seeds

I phoned other Northern Colorado nurseries and plant stores. Most had at least one milkweed in stock. The Perennial Gardener in Fort Collins sells only seeds, but had Beauty Beyond Belief's milkweed seeds available.

The Flower Bin, Longmont had all 3 milkweed species in stock as plants. 

Comments and corrections welcome.

Related blog posts: milkweeds and Colorado

Kathy Keeler, A Wandering Botanist
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  1. Nice blog and very informative thank you for sharing such a great blog.
    Singhania & Partners

  2. Fort Collins Nursery sells plants. Thanks for an informative blog that makes,it easy to narrow down which one to add to our garden.

    1. Yes, I talked to Fort Collins nursery, and have added them into the list.

  3. Hello! I just would like to give a huge thumbs up for the great info you have here on this post. I will be coming back to your blog for more soon.
    buy seeds

  4. But please be aware as to how toxic the sap is! I keep some plants for Monarchs but don't want them to take over the rest of the garden....removing them without getitng "burned" often eludes me!

  5. Awesome post, so detailed! Thank you

  6. This past season Tagawa Gardens offered the plants and also carry the milkweed seeds. Thanks for the blog we are always looking for information to pass to our customers.