Million Milkweed Seed Collection 101: Common Milkweed

 Common Milkweed is a favorite food plant for colorful monarch caterpillars. Help us plant more of this rich pollinator attractor!

Butterflies, like other pollinators, are an important part of food production for humans and wildlife, and for plant reproduction in Minnesota and the world. Unfortunately, pollinator populations in the U.S. have been falling for decades, but you can play a major part in their future.

Thank you for helping us reach a million

Join Great River Greening’s initiative to collect one million milkweed seeds within the seven county metro area andAnoka Sand Plain counties! This challenge is great for individuals, families, school groups, church groups, and community groups. The seeds will be nursery-propagated and later planted in beneficial areas.

25 pods per volunteer x 200 seeds per pod x 200 volunteers = SUCCESS!

Million Milkweed Seed Collection 101

All you need to know about collecting, cleaning, storing, & delivering

Common Milkweed Identification

  • Large, up to 3-4’ tall, with distinctive large oval leaves, usually growing in colonies of >3 plants
  • Milky sap appears on the leaf when broken off, eaten on the margins, or injured (but common milkweed is not the only plant that has milky sap)
  • Has distinctive pear-shaped seed pods in clusters. Note: Less than half the plants are pod-bearing in a typical year.

Collecting Seed

Common milkweed grows particularly well in disturbed areas such as roadsides, pastures, along railroad tracks, bike paths, road medians, agricultural and ball field margins, vacant land, your own yard and garden, and your neighbors’.

Do not collect from seeded or planted areas unless you can verify seed origin. We are collecting and accepting seed from the following locations:

The seven metro area counties

  • Anoka
  • Carver
  • Dakota
  • Hennepin
  • Ramsey
  • Scott
  • Washington

and from counties within the Anoka Sand Plain region

  • Anoka
  • Isanti
  • Sherburne
  • western half of Benton
  • western half of Chisago
  • southern tip of Mille Lacs
  • up to 5 miles west and 15 miles east of the Mississippi River in Morrison
  • eastern half of Stearns
  • the northeastern half of Wright

Milkweeds are a perennial plant entering fall senescence at the time of seed collection. No harm will be done to the plant if you minimize the damage to the stem and pod base. Leave at least half the seeds on the plant to disperse in the area. You can do this in two ways: Leave half the pods, or leave half the seed in the individual pods. Milkweed seeds need relatively bare soil in order to germinate.  If you think the surrounding area is ripe for milkweed propagation, then it is best to collect very lightly (20%) if at all.

Key Collection Details

1. Don’t Pick Pods Before Their Time

If you pick pods and open them to discover light brown (or white!) seeds, you won’t have viable seeds for planting. However, it’s no fun to separate seeds after the pods have burst open because of the fluffy mess! So what’s a milkweed gardener to do?

2. Use Rubber Bands or Twist Ties

These common household items can be lightly secured around milkweed pods to keep them from bursting open. Monitor the pods to see when they start splitting open and then cut off the pods and place in a bag. You can also press on the seam of each pod to see if it starts to pop.

3. If a milkweed pod won’t pop open easily, leave it for another time.

4. Keep seed dry. If you collect the seed pod when it is wet, spread it out to dry before bagging. The best place for it is a in a brown paper bag, which will allow any residual moisture to escape.

5. Keep seed from each collection location in its own bag, labeled with: Date of Collection, County of Origin, Collection Location, Your name. (Find forms to download in this packet.)

The origin of the original seed of a planted or seeded milkweed is typically unknown. This is why we ask for seed from wild plants, not planted or seeded – unless the landowner/gardener does know the County of Origin, record on your data form. It is imperative that we correctly know the county of origin for the seed.

6. Do not mix seed from different Locations or Counties.

Time your seed collection, and collect frequently.

Milkweed pods on a single plant will ripen at different times, so you may need to return to it. As of 8/31/16, some of the local milkweed pods are turning from green to brown spotted, an indication that they are getting closer to bursting at the seam. Pods vary in size but it is the size and development of the seed that we care about, so if they are good on the inside, please collect them. The ideal time to collect is when the pods just start to split, revealing brown ripe seeds but still in a compact cluster. Sometimes pods get split open by an outside force before the seeds are ripe. This will be the case if the seeds are white.   TIP: Wrapping unripe pods with a rubber band will keep them from bursting as they ripen, and you can return when they are ready to pick.


Fold the top of the bag and tape or staple closed, position the label on the outside. If you use plastic bags, leave the top open and stir the seed every day; this allows some passive drying of the seed. Once bagged, store in a cool dry place – garage floor, basement floor, outbuilding, or tile floor. Remember that uncleaned seed will fly all over, so think twice before bringing uncleaned seed indoors.

Drop Off Deliveries

We will accept seed drop at our shed (address below)

  • Tue 10/10         3 p.m. – 6 p.m.
  • Th 10/12            7 a.m. – 11 a.m.
  • Wed 10/18        3 p.m. – 6 p.m

We will also accept seed drop off at our Saturday fall events- and we’d love to have you volunteer at one! Look for the drop off location near the registration area.

We will turn these seeds into plants, some as plugs and others sown as part of a mix or hand seeded at volunteer events.

You can also can mail in your seeds
1) Be sure they are dry before mailing
2) Mark the package: For Immediate Open
3) Label as described above, including phone or email, in case we have follow up questions.


35 West Water Street, suite 201
Saint Paul, MN, 55107

We will turn these seeds into plants, some as plugs and others sown as part of a mix or hand seeded at volunteer events.

Milkweed Collection 501

Want more? Contact us if you have access to wild stock of:

  • Whorled Milkweed (found in dry areas)
  • Rose Milkweed (can be found in road ditches)
  • Butterfly weed (can be found in road ditches)

These plants are harder to identify, in smaller numbers, are often planted stock in gardens and natural areas, but just as important.


Questions? E-mail us or call our office at (651) 665-9500.

Return to the registration page
Download a pdf copy of Million Seed Collection 101
Download a page of labels for the seed bags
common milkweed photos
common milkweed seed pod photos

This project is made possible with support from National Fish and Wildlife Foundation e and Butler Family Foundation.