Milkweed Seeds Ripe for Harvest, Gather them Now for Future Monarch Butterfly Host Plants

The Antelope Horns milkweed we saw on our Texas roadsides in April are boasting robust seedpods now, ripe for the plucking.  Asclepias asperula was one of the few wildflowers to dot our highways and wildscapes this spring, a welcome contrarian to the dreary drought and voracious winds that defined the second quarter of 2011.   Fortunately, native species like these defy harsh conditions that leave other plants wilting.

We encourage butterfly gardeners to collect these seeds now to be cultivated into Monarch  and Queen butterfly host plants.  Surplus seeds can be sent to the Bring Back the Monarchs program, a milkweed restoration project organized by Monarch Watch at the University of Kansas at Lawrence.

Tropical milkweed seedpods and fluff

Monarch Watch, our favorite source for Monarch butterfly info, offers the following tips for collecting milkweed seeds:

• Mature pods are those that are within a day or two of opening. If you squeeze the pods and they don’t open easily, they usually do not contain mature brown seeds. Seeds well into the process of browning and hardening will germinate when planted the next season.
• Pale or white seeds should be not collected.
• Freshly collected pods should be dried in an open area with good air circulation.
• Once the pods are thoroughly dry, the seeds can be separated from the coma, or silk-like ballooning material (sometimes called “fluff”), by hand.
• Separation of seeds can also be accomplished by stripping the seeds and coma from the pods into a paper bag.
• Shake the contents of the bag vigorously to separate the seeds from the coma and then cut a small hole in a corner of the bottom of the bag and shake out the seeds.
• Store dried seeds in a cool, dry place protected from mice and insects – a plastic bag (reclosable) or other container in the refrigerator works well.

Those of us who plant Tropical Milkweed, Asclepias curassavica, in our gardens, can also gather seeds from this nonnative bloomer.  Althought technically an interloper, Tropical Milkweed is fine in a garden setting, and provides reliable host and nectaring for Monarchs and others.  Check out our milkweed guide for Texas  for more information.

One of many fun facts about milkweed is that the silky fluff, or seed threads  attached to each seed, are more buoyant than cork.  The silk “parachutes” catch the wind and efficiently facilitate milkweed propagation.  During World War II, the silk was used instead of down in aviation lifejackets.  Those who make quilts have even explored using the silky fiber as batting and more than one of us have wondered how much milkweed silk it would take to stuff a pillow.