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Water Germination of Showy Milkweed Seeds
In this test seeds of Asclepias speciosa (showy milkweed) were used. The seeds were collected in the fall of 2017. Under normal conditions the seeds would have fell to the ground in September. Their tough exterior would have been exposed to the weather during the winter. Snow and rain would have stratified the seed and prepared them to grow in the late spring.
The seeds being tested have not lived a normal life. These seeds were collected from ripe opening pods on top of milkweed plants that were beginning to go dormant after a long hot summer. After being collected they were separated from their seed pod and the milkweed silk that could have carried them thru the air. The seeds are dried for a few weeks in the open air and then stored in open bags indoors.
To be fair, nature does a pretty good job. Milkweed has been growing for thousands of years without any human intervention. On the other hand, one milkweed plant can cast out thousands of seeds and only a tiny fraction of those seeds will find the right conditions to grow. Milkweed seeds do benefit from Cold Moist Stratification which can be simulated in the refrigerator. It takes time to cold moist stratify milkweed seeds and may not be necessary. What if there is a faster way that works?
Materials
- 1 Seedling Heat Mat *Durable Waterproof Seedling Heat Mat Warm Hydroponic Heating Pad
- 1 Gallon Dechlorinated Water (tap water set out for 24 hours in an open container)
- 1 Thermometer *Non-contact Digital Laser Infrared Thermometer Temperature Gun
- 1 Plastic Dome any plastic tub that has an opening bigger then the plate will work
Start of Water Germination2/10/18 12:00 68° 26 seeds placed in coffee filter and placed on plate. Poured dechlorinated water into plate to submerge seeds and wet filter. 2/10/18 21:00 68° drained water off plate. Added fresh dechlorinated water. Day One2/11/18 09:00 66° drained water off plate. Added fresh dechlorinated water. 2/11/18 21:00 water temp was 63° based on infrared thermometer. Drained water off plate (dropped half the seeds in the sink). Put seeds back and added dechlorinated water. Placed heat mat under plate. Water temp at 22:00 is 70° |  26 showy milkweed seeds |
Day Two
2/12/18 09:00 drained water off plate. Added fresh dechlorinated water. Placed plate on the heating mat. Water temp at 10:00 is 74°
2/13/18 01:00 drained water. Added water. 74°
2/13/18 01:00 drained water. Added water. 74°
Day Three2/13/18 13:00 drained water off plate. Two seeds are showing growth. Added water. Placed plate on heating mat. 2/14/18 01:00 drained water. Added fresh water. Placed plate with seeds on heating mat. At least six of twenty six seeds are growing. Water is 75° at 02:00 |  germination begins at day three |
Day Four
2/14/18 13:00 eight seeds are showing growth. Drained water. Added water. Back on heating mat. Water back to 75° at 14:00
2/15/18 00:00 drained and replaced the water. Placed plate on heating mat.
2/15/18 00:00 drained and replaced the water. Placed plate on heating mat.
Day Five2/15/18 10:00 Five days since test began. Exactly 50% of showy milkweed seeds have germinated. 13 growing 13 not growing. 2/15/18 10:30 clipped the tip of the 13 ungerminated seeds and placed them in a new coffee filter in dechlorinated water on a plate on a heating mat. A plastic dome was placed over everything and the temp is now 80°-85° 2/16/18 00:45 added water to plate. Dome created higher temp which evaporated most of the water. |  50% germination at day five |
Day Six
2/16/18 13:00 drained water. Added water. Placed plate on heat mat. Added dome over everything.
2/17/18 01:30 drained water. Added water. Placed plate on heat mat and covered with dome.
2/17/18 01:30 drained water. Added water. Placed plate on heat mat and covered with dome.
Day Seven2/17/18 07:00 test complete. 21 of 26 seeds are growing in only seven days. FindingsWithin 5 days 50% of the seeds germinated. Thats 13 of 26 seeds growing in five days. Clipping of the 13 ungerminated seeds was done at the end of 5 days. The 13 newly clipped seeds germinated at a rate of 62% after two additional days. That means 8 ofthe 13 slow to germinate seeds did end up growing after clipping occurred Total germination of the 26 seeds was 21 seeds or 80.7% |  80% germination at day seven |
Water Germination of Common Milkweed Seeds
| Water germination of showy milkweed seeds worked very well. 80% of the showy milkweed seeds germinated in seven days. I am repeating the test with common milkweed seeds. When you ask the internet "how to grow common milkweed?" you will almost always be provided directions to Cold Moist Stratification of Milkweed Seeds. Does it work? Yes. Is there a faster way that works? Lets find out. |  26 common milkweed seeds |
| Water Germination of Showy Milkweed Seeds worked and you can read about that at the beginning of this blog post. I'm in the process of testing the method using common milkweed seeds. The results will be updated as they become available. As you can see in this photo the common milkweed seeds are in a coffee filter. The coffee filter is placed on a lunch plate. Dechlorinated water is poured onto the plate so the seeds are fully submerged. The plate is placed on top of a seedling heat mat. A plastic bin is placed over everything. The temperature of the water is measured with an infrared thermometer. Current temperature is 80 degrees Fahrenheit Try to keep the seeds between 75 degrees and 85 degrees. Latest update 3/6/2018 |  water germination of common milkweed seeds |
Day OneDay one requires an initial setup. Place the seedling warming mat on a table and plug it in. Set a plate on the seedling warming mat. Hopefully the day before this you have left water out for twenty four hours so it is now dechlorinated water. Pour the water into the plate. Place the milkweed seeds in the coffee filter. Set the coffee filter on the plate so the seeds are completely submerged in water. Water temperature should be 75 to 85 degrees. | Day One Video |
Day TwoClipping the milkweed seed will speed up water germination. The seeds can be clipped before going in the water but I like to wait twelve to thirty six hours before clipping the seeds. Letting them absorb some water in the first day makes them softer and easier to clip. | Day Two Video |
Day Three
Water change twice per day. Two of the twenty six seeds have root beginning to show from the seed.
Day FourAt day four there were ten seeds beginning to grow. Sixteen seeds are not showing any signs of germination. At this point I was still expecting more of the seeds to grow over the next few days. That did not occur. All the growth began in fewer then five days. The best thing to do with the common milkweed seeds that are not growing is to place them into cold moist stratification. |  |
Findings
The test continued to day seven. The length of the seeds roots increased but the ungerminated seeds did not germinate. The method is effective in germinating common milkweed seeds. Only some of the viable seeds seem ready to grow. I would like to guess then cold moist stratification prior to water germination could increase the germination rates of the common milkweed seed.
Water Germination of Whorled Milkweed Seeds
The whorled milkweed seeds I am working with this week have a verified germination rate of 93%. The goal is to start these seeds growing in less then a week. The test began with thirty whorled milkweed seeds.
Day One Thru Three |  |
Day FourContinue to drain and replenish the water twice per day. At day four there are a total of six seeds germinating in the bottom of the cup. The cup has always been siting on top of the *seedling warming mat. Testing of whorled milkweed continued until seven days elapsed. |  |
FindingsAt day seven the seeds were removed from the cup of water, untangled, and counted. The results were extremely rewarding. Seventeen seeds are growing and thirteen seeds did not grow. The germination rate is 56% in only seven days. While the germination rate did not reach the ideal number of 93% the results are considered successful. In addition to the number of seeds that germinated I was very surprised to see how long the roots had grown and how vigorous the seedlings appeared to be. When the outdoor weather becomes suitable for growing I will plan to water germinate many more whorled milkweed seeds. |  |
Water Germination of Mexican Whorled Milkweed
This test began with thirty mexican whorled milkweed seeds. The seeds were placed in a cup and water is added to one centimeter in depth. Twice each day the water was drained and replenished. At day two there was one seed growing and twenty nine were not. At four days there were seven seeds growing and twenty three were not. The test continued for a total of six days.
Findings
At the end of day six there were seven seeds germinated. The test concluded. The germination rate in water of the initial thirty seeds was 23%. Seven seeds grew and twenty three seeds did not germinate. The seeds that did sprout grew very long and healthy looking roots. I decided to plant the roots in a bit of soil. The outdoor temperature is not conducive to growing milkweed seedlings in March. I have placed the plants in soil in a red solo cup with drainage holes. They remain on the seedling warming mat on my kitchen counter. I'll try to provide an update as far as if they survive or die. I'm not very optimistic because I continue to have problems growing mexican whorled milkweed despite how well it seems to grow all around me.
