Twinleaf (Jeffersonia diphylla) is a rare and elegant native woodland wildflower found in rich, deciduous forests of the eastern U.S. It blooms in early spring with delicate white flowers and is best known for its unique paired leaves (hence the name "twinleaf"). Like many spring ephemerals, seed collection requires good timing.
Best time to collect seeds:
Late spring to early summer — typically mid to late June, depending on your location.
Signs seeds are ready:
After flowering, Twinleaf forms a green, urn-shaped capsule that splits open at the top like a lid (operculum).
When mature:
The capsule turns yellowish to light brown.
The lid lifts off naturally, exposing small, shiny brown seeds inside.
Seeds should be firm and dark, not soft or pale.
Seeds disperse quickly once the capsule opens, so check daily in late June and harvest as soon as the capsule lid loosens.
Collection and handling tips:
Harvest entire seed capsules just before they open.
Place in a paper bag or tray and allow to air dry indoors for a few days.
Gently shake or tap to release seeds.
Germination notes:
Twinleaf seeds have double dormancy and typically take two seasons to germinate.
They require warm stratification (~70°F) for a few months, followed by cold stratification (35–40°F) for 3–4 months.
Alternatively, sow fresh seeds outdoors in a protected site in summer for natural stratification cycles.