Earlier this month, I shared green milkweed vine seeds with my fellow Texas Master Naturalists/Highland Lakes chapter. Naturally, each one asked the same question: How do I germinate these?
Well, Randy Johnson with Randy Johnson Organics answered that question at the 2015 Texas Pollinator Powwow in Kerrville. Here are his instructions per his many years of germinating experience:
Separate the fluff from the seeds. Place the seeds in a paper sack with a pebble and shake it. The seeds will separate and fall out like black pepper flakes.
Most perennial milkweed seeds require cold moist stratification, which prevents seeds from germinating too soon. In the wild, milkweed seeds absorb moisture during the winter and sprout in the spring.
To germinate your own seeds, moisten a half baggie full of sand and add seeds. Blow up the baggie like a balloon and shake the seed/sand mixture in order to make sure the seeds make good contact with the moist sand. Roll up the baggie and place in refrigerator.
Check the baggie in three weeks. Remove if the seeds have germinated. Timing of stratification is important because once you get the seeds wet, they can sprout in 30 days.
If you stratify around March 30, pull out the seeds from frig April 30 and plant in the ground.
If you stratify later, place the seedlings in 4-inch pots, hold until fall, and plant around November 1.
In a recent email to me, Randy adds: "I would begin stratification mid March north of Waco and March first down where you are. Best strategy is to direct sow after stratification. Remember: The best plant results from a seed directly sown. If you can't do that, then you should plant the seedling in the deepest container available. Six inches would be good. The problem long term with a 4-inch pot is the taproot curling. I would go to a one-gallon after about two months or so if I had to wait until fall for installation."
THANK YOU, RANDY!