Native Here Nursery has grown California milkweed (Asclepias californica) on and off for many years. However, with the increased interest in saving monarchs, we now make a point of growing a supply every year but they are popular and our current supply is gone. (Note: We have a good supply of Asclepias fascicularis, the most common species). Here’s a photo of California milkweed seeds growing now that will be available in time for this fall’s planting season (click to enlarge):
The seeds germinate in an interesting way: The radicle emerges from the seed, pokes into the soil, and becomes a root. Then it pushes the seed cover along until it has the strength to raise it. Shortly after, the cover dries and falls off and the cotyledons (first leaves) emerge. The photo above shows a seed in each stage. Ptelea crenulata (hop bush) seeds also germinate like this.
– January 2020