Frequently Asked Questions

1. Q: How much shade is required in propagation?
  A:

• Ideally 80 - 90 % (600 - 1100 ft candles light, depending on heat) for the first week, then 60 - 70 % (1400 - 2000 ft candles, depending on heat) until roots are developing, then 40 - 50 % (3500 - 4500 ft candles, depending on heat) until planting. The shade percentage is in addition to the shade of the greenhouse structure and cover.


• If, during the first few days, the mist frequency on a sunny day at noon is below 15 minutes, then more shade should be applied.


• The cooler the conditions the more light can be given.


• It is always better to give more shade than to increase the mist.

2. Q: What works best against Fungus gnats?
  A:

• Distance sprays work well. They are safe if applied not more than every 4 weeks. Sprenches and drenches can cause problems on poinsettias.


• Duraguard at 25 oz. per 100 gal works very well but is expensive. Do not apply if using Oasis.


• Drenches with Nemasys, Nemashield or other Steinerema feltiae products work very well and are more economical than Duraguard.


• A drench with Hypoaspis predacious mites work well if applied 2 weeks after a Steinerema feltiae drench.

3. Q: When is the best timing for growth regulation?
  A:

• Right after the cuttings are rooted, before the pinch and right after the pinch to avoid long first internodes and uneven branching.


• Usually growth regulation is done 2-3 weeks too late. This is especially true for medium to vigorous varieties.

4. Q: What works best to avoid stem breakage?
  A:

• Pinch, so you will have 6-7 branches.


• Keep pot tight for 5 weeks after pinching and at the same time growth regulate to avoid stretching.


• If possible space twice.


• Use upright varieties.


• High light levels, except the first 3 days after pinching, to strengthen branches.


• High calcium levels in fertilization program from the beginning.


• Use of growth retardants before and after the pinch.


• Grow compact plants (14-16 inches)

5. Q: What is the ideal feeding schedule?
  A:

• Always depending on water, soil analysis (every one to two weeks) and overall condition of the plant:


• Make sure there is enough supply of calcium, magnesium and minor elements from the beginning


• Keep pH at around 6.0


• 30 % ammonium from a well balanced fertilizer like 20/10/20 up to October 1, 300 ppm nitrogen, alternating with 14/0/14 every third feeding


• 15 % ammonium up to three weeks before finishing, 250-300 ppm nitrogen. Alternate 20/10/20 with 14/0/14


• Slowly decrease from 250 ppm to 80 ppm nitrogen of 14/0/14 up to three days before shipping.


• Leach heavily two to three times to eliminate all salts right before shipping

6. Q: How can I best avoid an uneven plant habit?
  A:

• Treat young plants in propagation, before and after the pinch with growth regulators to avoid stretching of the bottom internodes of the branches.


• Make sure to apply growth regulators (after the previous applications around pinch time) as needed.


• Provide 400 ft candles up to the pinch and again two days after the pinch for a strong plant structure.


• Select varieties that naturally have a more rounded plant habit.

7. Q: What is the best way to avoid Pythium?
  A:

• The best: Use Subdue Max at ¾ oz. per 100 gal, alternating with 6 oz. Truban per 100 gal every 4 weeks, starting right after planting


• Use the best coarse peat available.


• Avoid over watering and drying out of the media.


• If soil becomes dry, use clean water before feeding.


• After possible root damage, drench with Subdue Max at 1 ounce per 100 gal.

8. Q: How do I best avoid heat delay?
  A:

• Select heat delay insensitive varieties.


• Make sure the temperature all night (especially important under blackcloth) is below 71 F.


• Provide proper air flow, so there are no pockets of warm air in the greenhouse.

9. Q: What's the best strategy to avoid bract edge burn?
  A:

• Spray calcium chloride di-hydrate at 1 lb. per 100 gal from mid-October until sale.


• Use dark leaf varieties that are bract edge burn resistant


• Increase transpiration rate by lowering humidity.


• Supply sufficient calcium nitrate.


• Ensure a healthy root system.


• Leach strongly twice before shipping to avoid bract edge burn after shipping.

10. Q: It's October. My plants are too short, what can I do?
  A:

• Increase the temperature to 75 - 80 F day and 68 - 70F night


• Fertilize with a "soft " fertilizer, like 20/10/20

11. Q: It's October. My plants are too tall, what can I do?
  A:

• Cool down to 65 day and 68 night as much as possible. Go to 65 night only three weeks before shipping, otherwise bract size will be reduced.


• Apply Bonzi drench not earlier than 3 weeks before shipping in the north (4 weeks in the south)


• Fertilize with a "hard" feed, like a 14/0/14

12. Q: What is a good whitefly program?
  A:

• To be most effective, Marathon should be applied 3 weeks after planting. Make sure to not leach it out when watering the following 10 days


• Before the Marathon application, Distance, Endeavor, Pedestal, Talstar, Sanmite, Enstar II, Beauveria bassiana, Preclude, Attain, and Thiodan (through cold fogger) are safe products. Distance works well as a spray before the Marathon application and as a second spray application before the bracts color up.

13. Q: What can I use to control whitefly on poinsettias in color?
  A:

• Spray applications of Marathon II or Sanmite, combined with Capsil.

14. Q: What can I do for late season Botrytis control?
  A:

• Exotherm Termil works well up until the bracts show color; however, some growers use this product all the way through full color (note the label forbids the use on "flowers" of poinsettias). Make sure there is no moisture between the leaves, as this will cause burn.


• Another option is using a Decree spray application with Capsil.

15. Q: I am 3 weeks away from shipping and my plants are not going to be ready. What can I do to speed them up color wise?
  A:

• Keep the nights at 68-70F, and warm the days up to 75-78F. Any shade should have been removed to allow as much sunlight as possible to reach the plants, as long as light intensity does not exceed 3000 ft candles.


• Experiment with Fascination (currently not labeled for use on poinsettias) at 1-2 ppm to speed up the coloring process.

Fischer USA, Inc. does not endorse any product listed in this technical information. Product recommendations are based on our experience in working with the products directly, observation, or conversations with personnel within the greenhouse industry and academic community. Check your local or state regulatory agency for certain chemical and pesticide restrictions.