Poinsettia Reblooming: 8 Weeks of Nightly Darkness Starting Late September

The Protocol

1. Late Sept: Begin 12 hrs total darkness nightly (box/closet) + 12 hrs good light daily.
2. Night temp ~63°F.
3. Water normally.
4. Continue 8 weeks until bracts color.
5. Then display normally.

Critical

Even brief light at night disrupts flowering. Most buy new yearly—this is labor-intensive.