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Poinsettia Reblooming Schedule: Pruning and Dark Treatment Timing for Holiday Color

Poinsettias (Euphorbia pulcherrima) need strict photoperiod control to rebloom. Missed August pruning and September dark treatment means Valentine's blooms, not Christmas.

Year-Round Calendar

Critical Details

Darkness must be TOTAL – any light leak resets clock.
Temperature consistency: 65–70°F during dark period.
Water when surface dry; don't fertilize during dark treatment.

If Starting Now (Late)

Begin dark treatment immediately → blooms in 8–10 weeks (Valentine's). Prune hard first if leggy.

Resources

UIUC Extension, Bachman's, GardenGal.

Mark your calendar; precision = poinsettia perfection.

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Month	Action
Jan–Mar	Cool (60–65°F), bright light, water when dry. No fertilizer.
April	Cut back to 6–8". Repot if needed. Start fertilizing (balanced ½ strength).
May–Jul	Outdoors (shade→sun). Pinch tips monthly for bushiness. Fertilize 2×/mo.
August	Final pinch (cut ⅓). Bring indoors before 55°F nights.
Sep 21–Nov 30	Dark treatment: 14 hrs uninterrupted darkness (5 PM–7 AM). Cover with box or closet. 65–70°F. Bright light 10 hrs.
Dec	Color shows. Stop dark treatment. Enjoy!