CULTURE – FINISHING GUIDE
Water and Fertilizer • Maintain even moisture. Dramatic swings from wet to dry can damage roots and contribute to Pythium root rot. • Maintain a media pH of 5.7-6.3. Poinsettia should be grown with a constant liquid feed program of 200- 250 ppm N. Cal-Mag feed is recommended, as they need a good source of Ca. Know your water quality to choose correct fertilizer and better manage media pH, as pH above 6.5 can trigger Mg deficiency. • Maintain a media EC of 1.2-2.0 from a pour-through or 0.8-1.3 for a 1:2. A healthy and active growing poinsettia will consume a lot of fertilizer. If, while consistently fertilizing, you find that media EC is still low — that is okay because modern poinsettias will aggressively uptake nutrition. • Utilize tissue and analysis to ensure nutrition is adequate. Plus, don’t forget the Moly!
Finishing Environment Day temperatures: 68 to 78°F (20 to 26°C) Night temperatures: 65 to 70°F (18 to 21°C)
• Keep humidity high by wetting floors and minimizing air movement. Use drip irrigation and high-porous potting plant media with pH adjusted with limestone. • Be sure media is well drained, with a maintained pH of 5.7-6.2. Avoid pH of 6.6 and higher at finish, as high pH and reduced fertility levels can contribute to bract edge burn and Mg deficiencies. • Negative DIP works well for height control one hour before sunrise until three hours after.
PRO TIP Reduce feed as the crop finishes in November.
Deficiencies The most common deficiencies are Calcium and Magnesium. • Lack of Ca causes bract edge burn on poinsettias. Ca moves in water, so high transpiration rates are important. • Supply Ca in fertilizer; not all “balanced” feeds have Ca. Many growers utilize Calcium Chloride or Calcium Chelate sprays starting in mid-to-late October to help with bract edge burn. • Elevated pH is associated with higher Calcium feeds and/or water alkalinity. This can result in Mg deficiencies. If pH is above 6.3 in mid-October, supplemental Mg is needed.
Other Deficiencies
Potassium deficiency
Phosphorus deficiency
Calcium deficiency
Calcium deficiency
Nitrogen deficiency
Iron deficiency
Magnesium deficiency
Boron deficiency
Molybdenum deficiency
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