Potted Plants

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Potted Plants Poinsettias Topic 2173 Nick
Wendling
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The Poinsettia

• The flower is small and yellow
• The flower is located in the bracts
• Bracts are the leaves that give the poinsettia
  their color
• Poinsettias need short days to develop the
  flower, which is necessary for bract coloring.

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The Poinsettia

• Poinsettias should be grown in full sunlight
  during long days to develop leaves and increase
  stem length.
• The plant develops the flower buds naturally
  during late Sept. and early Oct.
• The bracts get their color in Nov. and Dec.

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The Poinsettia

http//www.poinsettiaonline.com/stores/webpage.cfm
?WebPage_ID14DID30
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Greenhouse Management

• Factors to Consider
• Light
• Temperature
• Moisture
• Ventilation
• Climate

http//www.igcusa.com/ghse.htm
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Light

• The greenhouse should be located to receive
  maximum available sunlight.

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Temperature

• Day temperature 5 to 10 degrees higher than night
  temperature.
• Night temp should be 65 degrees with day temp
  being around 70-75 degrees.

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Moisture

• Plant growth is dependent on moisture
• Watering helps to carry dissolved nutrients to
  the plant.
• The amount needed is dependent on the outside
  conditions. (sunshine or clouds)

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Ventilation

• Ventilation is the movement and exchange of air
  in the greenhouse.
• This ensures proper temperature throughout the
  greenhouse.
• Helps control relative humidity and plant
  diseases.

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Planting and Spacing

• Poinsettias can be grown in any size pot.
• The size of the pot will determine the overall
  size the plant will grow to.
• In larger pot sizes, often more than one plant is
  planted. (3 plants in a 6in pot or bigger)

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Pinching

• Removal of the terminal bud
• Four or five nodes should remain
• Increases the number of bracts per plant
• Causes the plant to be fuller

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Soil Mixes

• Needs to be porous and well drained
• Soil should be free of insects and diseases
• Soil should be sterilized at 180 degrees for
  thirty minutes.

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Fertility

• Poinsettias require a regular fertility program
• Use a complete fertilizer (contains Nitrogen,
  Phosphorus, and Potassium)
• 20-10-20 is a commonly used formulation

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Growth Regulator

• Control the height of plant so it stays a
  marketable height.
• Enhance the color of the bracts so it is more
  desirable.

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Insects

• Common insects are whiteflies, mealybugs, spider
  mites, and fungus gnats
• Can be controlled by chemicals
• IPM methods can be used for control
• Keep the greenhouse clean to prevent insect in
  the first place

http//www.corkyspest.com/mealybugs.html
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Disease

• Common diseases are root rot and powdery mildew.
• Can be controlled by use of fungicides
• Ensuring the soil is clean before planting is
  best way to prevent disease.