Found this info on a grower bulletin which would tie in nicely with Brians info:
Soil: Any well-draining, normal greenhouse soilless media will suffice. The breeder uses SunGro852, which is the same as Fafard 52 soilless media.
• Tagging: The breeder highly recommends NOT putting tags in at the time of fall planting. A tag creates a “water arch” when watering and can also lead to small dots of mildew prior to shipping next spring.
• Watering: Keep freshly potted chicks on the moist side during their active fall growth cycle. Chicks put on a tremendous amount of growth during the cool months of September, October and November. The breeder hand waters all Chick Charms for best results. However, several varieties require less water and should be kept on the drier side. These drier growing varieties include Key Lime Kiss, Cotton Candy and Fringed Frosting.
• Fertilizing: Fertilize heavily during the fall growth spurt cycle with 200 to 300 ppm general all-purpose fertilizer or 200 ppm of a good Calcium-Magnesium (CaNO3/MgNO3) based fertilizer.
• Temperatures: Keep fall greenhouse temps at 65F (18C) heat/75F (23C) vent/80F (26C) fans until December 1. Then provide a gradual temperature reduction over a two-week period. Finally, hold them at 34 to 40F (1 to 4C) for the rest of the winter.
• Vernalization: Chick Charms do require an eight-week cold/vernalization period to obtain their best coloration the following spring. Keep at 34 to 40F (1 to 4C) for an eight-week period beginning December 1 and running through late January.
Spring growing
• Fertilizing: Use light to no fertilizer in the spring on Chick Charms. You can use minimal 50 ppm fertilizer in the spring with every third watering. However, too much nitrogen can prevent bright coloration and cause green, lush growth instead.
• Watering: Keep plants on the moderately moist side. This helps encourage chicks to “plump” up and fully fill the pots.
• Temperatures: Increase temps to 60F (15C) during the night and maximum 75F (23C) during the daytime.
• Insects: Watch for root aphids, which are a white, cottony mass on the root system. If detected, treat with a Safari drench at 9 oz./100 gal.
Miscellaneous production notes
• Always water ONLY in the cool morning hours prior to 10:00 a.m. Later watering in the heat of the day can cause instant rot.
