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)
Where nutrition deficiency symptoms occur on the poinsettia plant
Pinching • Pinching plants before breaks significantly form is critical to support even branching. On very early branching varieties, such as Christmas Feelings, the pinch should be done on Day 12 to 14 after planting. On other varieties, the pinch should be done when the roots reach the edge of the pot. Late pinching will result in uneven branching. • Pinch according to leaf count, based on finished specs. For example, leaving 6 to 7 leaves below the pinch will produce a plant with 6 primary bracts. • Removing 1 to 2 leaves just below the pinch will increase light penetration, promoting stronger and more uniform branching.
Calcium, Boron, Molybdenum
• 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 DIF works well for height control one hour before sunrise until three hours after.
Magnesium, Copper
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
Nitrogen, Phosphorus, Potassium, Boron (toxicity), Manganese (toxicity)
Before pinching
After pinching
Iron, Manganese, Zinc
Potassium deficiency
Phosphorus deficiency
Moisture Management Do’s and Don’ts • Part of a good moisture management program is focusing on building your foundation by creating a consistent language of moisture levels within your growing team. Staying in the middle of the road and quantifying your moisture levels, including knowing when and how much to water, will help keep your crop healthy. • Avoid "growing dry” in an effort to prevent root diseases, but also be careful of big swings in moisture management or overhead watering late in the day. Providing your team with a planned watering procedure will keep them from having to guess when and how much to water.
Branch development after 7 days
Iron deficiency
Calcium deficiency
Calcium deficiency
Nitrogen deficiency
Proper water management leads to perfect roots
Molybdenum deficiency
Magnesium deficiency
Boron deficiency
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43 Highest-Quality Genetics From the Number One Supply Chain
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