I'm so excited that I my a.humistrata returned from last year. I was lucky to find a source of seeds (central Florida ecotype) and started my a.humistrata journey in summer 2019 and I want to share my results!
SOAKING SEEDS: I've tried multiple methods of starting seeds, from placing directly into cell trays (or ground), cold moist stratification, hot water soak, clipping and also just soaking and placing in the sun. This seed set, I soaked in hot water and placed in the sun. They sprouted in only a couple of days.
Note: The first of the sprouts, I planted directly into a deep (~2ft) container and these had the most growth last year & returned first this year.
SOIL MIX: Once sprouted, I placed (carefully!) into deep (8in) cone-tainers. I tried to channel "central Florida soil type" and knowing these are also referred to as Sandhill and Pinewoods milkweed, adjusted my mix accordingly. I used an equal mix of potting mix, sand, perlite and degraded pine mulch (locally available at my local hardware store and known as soil conditioner).