Poinsettia

Plant: Poinsettia

Term: Short-day Plants

PoinsettiaEuphorbia pulcherrima• Interior Plant in Va.• USDA Zones 9-10• Bracts turn red, white, pink in winter• Flowers are centered in the bract• Plants ooze a milky sap• Poinsettias are not poisonous but the sap can

cause skin irritation• Many people continue to grow their poinsettias

outdoors through the summer• Poinsettias can be forced to turn red again by

controlling the light period

Short-day Plants

• Plants that bloom when the hours of sun per day is decreasing (Fall – Winter)

• Carnations• Poinsettias

Poinsettia

• Euphorbia pulcherrima• Interior plants• Grown for the Christmas market• Bracts turn red & plants bloom under short

day conditions • Plants stop growing when days get short• Propagate by cuttings

Poinsettia Production

• Large Growers have “Stock Plants”• Keep days long by artificial light

in the late winter and early spring• Take cuttings in summer & root them• Ship to growers who provide conditions to

turn red for Christmas – like us

Poinsettia Finishing

• Days must be short• No artificial light from onset

– (equinox 1st day of fall)• Plants may be pinched or sprayed with

PGR to keep good form

Poinsettia Care

• Problems:– White flies– Scale– Spider Mites

• Don’t use chemicals on leaves after color change begins

• Keep well spaced• Keep temperature between 60° - 80°

Schedule

• Want poinsettias ready for sale on December 11th.

• Today is Nov 12, so – 29 days to sale date• Speed up or slow down color change by

controlling greenhouse temperature• Find our average daily temperature