Cold Moist Stratify milkweed seeds

Cold Moist Stratification of Milkweed Seeds  

By Brad Grimm at Grow Milkweed Plants

​Cold Moist Stratification (CMS) describes the process that seeds naturally progress through. Timing of the process occurs naturally when the seed is dispersed from the milkweed plant in the fall and continues until the seed begins to grow in the spring. The process I am presenting for CMS is designed to simulate winter conditions and can be applied to the milkweed seed at any time of the year in your home.

Winter sowing milkweed seeds is the natural way to break their dormancy. The cycle of freeze and thaw mixed with occasional rain or snow does two things. First, the seeds coat is physically scraped by movement over the dirt. Second, the inner biology is adjusted because the seed has been imbibing water over the winter. Once the warm days arrive in late spring seed is prepared for grow.

Planting milkweed seed between Thanksgiving and Christmas is my favorite. It's nice to get the seeds in the dirt before the snow arrives. Casting milkweed seed over the snow leaves them exposed to become the food for small animals. 

Materials needed:

• tap water
• paper towel
• milkweed seeds
• ziplock bag
• permeant marker
• dish soap (optional)
• refrigerator 

prepare the work space

Process:

1. Clean the surface of your counter thoroughly.
2. Take one sheet off your roll of paper towels.
3. Wet the paper towel with cold tap water from the sink.
4. Optionally - Add a drop of dish soap. Reduces mold formation on paper towel.
5. Use one hand to squeeze out all of the water you can from the paper towel.
6. Spread out the paper towel on a clean surface.
7. Evenly scatter the milkweed seeds onto the paper towel.
8. Fold/roll-up the paper towel and seeds. 
9. Place the paper towel, now covered in seeds, inside the ziplock bag.
10. Seal the ziplock bag while removing excess air from inside the bag. 
11. Print the date and seed species on the baggie using a permanent marker.
12. Place the bag in the refrigerator for 40 to 60 days.
13. Set a reminder to retrieve the seeds 40 to 60 days from today. 
14. When 40 to 60 days have elapsed, remove the seed bag from the fridge.
15. Leave the seed bag on the counter for 2 to 7 days. 
16. Plant the seeds and water daily till they germinate.

Download the Cold Moist Stratification .PDF file so you will have it ready when you begin growing milkweed seeds.

Guide to Cold Moist Stratification .PDF
File Size:	7050 kb
File Type:	pdf

Download File

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Repeat success indicates that the process works!

CMS with showy milkweed seeds

On 2/18/17 I prepared seven baggies with showy milkweed seeds. Pictured is midway thru the process. On the left I am in step 7. Dormant seeds are spread on the moist paper towel.

showy milkweed seeds

CMS with woollypod milkweed seeds

In May 2017 I purchased woollypod milkweed seeds on ebay and began the process of CMS to prepare them to grow. These seeds are really big! The seeds were collected in the fall of 2016 and began dormant.

woollypod milkweed seeds

At step 9 the seeds are prepared to go into the refrigerator for 40 to 60 days. 

Step 14 was hard to wait for. It's not much to look at right now. Exciting biological changes have actually been occurring inside the seed over the last 40 days. 

Step 12 looks easy. Waiting can be the hardest part. Give the seeds 40 to 60 days in the refrigerator. My fridge has a temperature display on the door. Looks like the seeds are about 37 degrees.

Step 15 is pretty cool to see. The seeds are growing right inside the baggie! Time to take the seedlings out of the paper towel and get them in the ground. Some of the seeds root is piercing thru the paper towel. Just pull the towel apart and be careful not to harm the seeds root.

Update

Since February for the showy milkweed and May for the woollypod milkweed was to late in the year to winter sow I used the method described above. All and all it worked out great! By August the woollypod milkweed plants were beginning to look like real milkweed.

woollypod milkweed plants August 22, 2017

As summer became fall the temperatures outside began to cool off. The sun set a bit lower in the sky and the woollypod milkweed went dormant along with all the other plants. It's December 2017 now and the woollypod milkweed is completely dormant. I have been storing them in the garage for the winter. Hopefully in March of 2018 I will be bring them out to enjoy the warmer weather.