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Milkweed Seed Collection

Timothy macht milkweed pod 940x235

If you have access to native milkweed seeds, here are some tips for seed collection that you can use to share seeds with different conservation organizations or community/neighborhood projects or to plant yourself and expand habitat for monarchs!

Guidelines for Seed Collection

What to collect

  • Know your milkweeds! If you do not know the species, collect for personal use only. Propagation space is the most valuable space in the greenhouse, so mislabeled or mixed seeds can cost nurseries and distributors money. Do not collect seeds of rare or endangered milkweed species.
    • It is easiest to identify species when they are in bloom. If you are planning to collect certain species, identify each species before the seed pods form.
  • High-priority milkweed seeds needed include (Monarch Watch Milkweed Market):
    • Asclepias tuberosa- butterfly milkweed 
    • A. Incarnata- swamp milkweed 
    • A. verticillata- whorled milkweed 
    • A. perennis- aquatic milkweed 
    • A. oenotheroides- side cluster (West Texas) 
    • A. asperula- antelope horn, spider milkweed 
  • Only send native, wild milkweed seeds. Distributors and nurseries want to be able to promise their plants came from a native milkweed population
  • Check the seeds for viability before putting a lot of work into it. Break a few seeds open. The exterior of the seeds should be brown. If they are distinctly creamy white on the inside (of the seed), they are viable. If they are brown or black and paper-thin on the inside, they are not good seeds.

When to collect

  • Collect only ripe pods. Pods do not always ripen at the same time, so you should assess each pod individually. You do not need to remove the pod from the plant to assess ripeness.
  • Pods are ripe when they open at the seam with light pressure. If the seam does not split open with a gentle squeeze or press, the pod is likely, not ripe yet.
    • Ripe seeds will be brown.

How to collect

  • Split the pod at the seam and peel open. Use your fingers to pull the seeds and the silk out.
  • Do not collect open pods with numerous milkweed bugs on the seeds or pods. Avoid introducing milkweed bugs into the bags in which you are placing pods.
  • It is always best to collect only a portion of the seeds in a particular location and leave some for natural regeneration.

Seed Separation

Distributors and nurseries always prefer to receive seed that has been separated from the pods and silk because there's not always time to do it promptly. There are many different ways to do this:

  • To watch a video of how to do this by hand, click here.
  • To watch a video of how to do this with a vacuum and a sifter, click here.
  • To watch a video of how to do this with a vacuum and homemade seed separator, click here.
  • You can put the silk material and seeds in a paper bag with stones or coins and shake it to separate the silk from the seeds, then cut a small hole in the bottom of the bag to pour the seeds out and keep the rest contained.
  • In a dryer on the cool setting, you can put the silk material and seeds in a closed, cloth bag with a tennis ball.

Labeling Your Milkweed Seeds

Labeling the seeds you collect is incredibly important. Be sure to record the species name, collection location, date, and your contact information. It's helpful to bring labels with you to your collection site so you can fill it out while you collect. Wild Ones has an excellent resource that includes printable labels.

Print seed collection labels here

Seed Storage

  • Store moist pods or seeds in breathable containers, such as paper bags.
  • For long-term storage and dry seeds, use plastic containers. If you are collecting the seeds for yourself, friends or family, store the dry seeds in an airtight container in the refrigerator. They may remain viable for years if you do this!

Seed Packaging for Distribution

If you are planning to send your seeds to a nursery or distributor, be sure to properly package your seeds before shipment.

  • Never send wet seeds. Always dry your seeds thoroughly in breathable containers before packaging.
  • Label all seeds properly using the guidelines above.
  • Ensure your species ID is correct.

Seed Use

  • In order for the seeds to germinate, they must be stratified, meaning they need cold treatment. You can plant them in the fall, and the winter temperatures will naturally stratify your seeds. For more information on stratifying your seeds indoors, visit Monarch Watch's Growing Milkweeds page.

Additional Resources