Controlling Whiteflies on Poinsettia and the Photoperiod Secret for Reblooming

Whiteflies on Year‑Old Poinsettia

Whiteflies are tough—they fly off when sprayed and return. Soil applications of Murphy's oil won't reach them.

Spray horticultural oil on all foliage (half strength).
After recovery, cut stems back to 4 inches.
For rebloom: from late September, give 15 hours of total darkness (5 pm–8 am) daily.

Water when soil surface dries; fertilize monthly with soluble feed. It's a commitment, but doable.

Tropical Plants: Bromeliad Bloom Cycle: What to Expect After Flowering; Hibiscus Orange/Red Larvae: Caterpillars, Hand-Pick or Bt; Gloxinia Rest Period: Dormancy Requirements for Reblooming; New Guinea Impatiens ID and Care: Tropical Balcony Success; Hard White Speckles on Money Tree (Pachira): Scale Insect Infestation; Whitefly Invasion on Hibiscus: Neem Oil, Patience, and Cold Hope; Myrtle Topiary White Fungus: Likely Mealybugs; Mealybugs on a Child's Cactus: Safe Alcohol-Soap Spray; Eliminating Fungus Gnats from New Houseplants: Systemic Soil Treatment and Repotting; Identifying a Cotyledon Succulent: Care Tips for Your Clearance Find

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