Living Acres

How to Store Milkweed Seeds

October 28, 2016

Seed Storage

Whether you have mature milkweed growing in your backyard, have an avid milkweed-growing friend or know of a public patch of milkweed – fall is the time to harvest the seeds. While there are numerous online videos on how to harvest the seeds from mature milkweed pods, the question that arises is how to store these seeds until the appropriate planting time in spring.

Dried milkweed seeds should be stored in a cool, dry place. Use a sealable plastic bag or a paper bag, folded over and stapled shut, to protect the seeds from mice and insects. Many milkweed growers also label the bag with the milkweed species and the harvest year.

If you are planning to plant this fall’s harvested milkweed seeds next spring, it is best to store them in your refrigerator. This will give the seeds the vernalization (a fancy term for cold treatment) needed to come out of dormancy and sprout when planted.

According to Monarch Watch, the best way to achieve the required vernalization is through stratification. In horticulture, stratification is the process of treating stored seeds prior to planting to mimic natural winter conditions that a seed needs for germination.

To stratify milkweed seeds, some planters will store their refrigerated seeds in moist potting soil. However, if you prefer not to keep potting soil in your fridge, an alternative is to keep the seeds between moist paper towels. This method will prevent fungi and bacteria from attacking the cell. If the seeds do not receive vernalization and stratification, the percentage of seeds that germinate decreases dramatically. You can also improve germination rates by soaking refrigerated seeds in warm water for 24 hours before planting.

Another way to stratify seeds is to plant them in the ground for the winter. After harvesting milkweed seeds, gather them in a mesh bag. The toe of a pair of nylons works well. Dig a small hole roughly 2 to 4 inches deep and place the mesh bag in the hole. Loosely cover with soil. Make sure to mark the spot you planted your seeds so you can easily find them the following spring.

Finally, apply scarification to your stored seeds. Some seed coats require physical agents to aid in the breaking down of the seed coat. Accomplish this by placing the seeds in a container with course sand or salt and shaking it for 30 seconds.

By following these steps, you will increase the likeliness of a successful milkweed grow rate. For more information on how to plant and tend to your milkweed, visit


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