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Thursday, Aug. 6th 2015

Milkweed Seed Collecting Time is Just Around the Corner

I noticed yesterday that my butterfly weed plants (Asclepias tuberosa) have pods.  They’re not ready to harvest just yet, but soon.  Collecting milkweed seeds is an important way we can help monarch butterflies…as long as said seeds are eventually planted, that is!



If you’ve already scouted out places to collect, and know when and how to harvest and how to propagate the seeds, you need not read any more.  What you might want to do, however, is teach others in your community how to do it and encourage “seed harvesting” days.

If you are new to harvesting milkweed seed, here are the basics:

Collect No Pod Before Its Time

Ripe pods will split open when you push on the “seam” of the pod.  The seeds should be brown or “browning up.”  If the seeds are still pale, do not collect. Some people put rubber bands or tie the pods shut, which works well if you cannot check frequently enough to collect at “just the right time.”

Don’t Rub Your Eyes When Collecting

Milkweed sap can damage your eyes. First it’s an irritation, then the cornea may become cloudy, and it can take a week to clear up. 

Learn Some Easy Tricks to Separate Seeds from Floss

Here is a good video that shows how to do it. 

Removing floss from milkweed seeds

If you are not planting outdoors this fall (before the first frost) or starting plants in a greenhouse, make sure the seeds are dry for storage

Monarch Watch has some good information on how to store and grow milkweed from seed.  
Monarch Watch Growing Milkweeds

Have more seed than you need?

If the seed was collected in Missouri, send it to Missourians for Monarchs.  
Here’s how:  

Package the seed in plastic bags (dry it first) with a label inside that identifies:

  • Donors name and affiliation.
  • Location of collection: part of a county, near a town, GPS or something to nail down approximate location
  • Quantity collected/donated (ounces or pounds)
  • Specie of milkweed (common name is okay)
  • Date harvested

Mail to:  

Phil Rahn

511 Kenilworth Ln

Ballwin, MO 63011

Send Photos of Your Harvesting Outings to Sarah at Missourians for Monarchs at

Separating seeds is sort of like a quilting bee without the fabric, needles and thread.
A “Just Right for Separating Seeds from Fluff” swamp milkweed pod.
Probably should just let this one go…it’s past its prime collection time. That, and check out all the milkweed bugs!! 

QUESTIONS about seed collecting?  Send them to Sarah Berglund at Missourians for Monarchs or check out this helpful FAQ site from Xerces Society:  Milkweed FAQ from Xerces Society


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University of Missouri Extension Master Gardener Program