For holiday blooms:
bsharf said: we are just fighting Mother Nature since dormancy depends on day length, temperature, and dryness.
If you do the math,
to bloom around Dec. 25th count back 8 weeks to the end of October--this is when the bulb needs to think that it is spring and come out of it's winter rest period aka dormancy.
and what that means is that it needed to have its winter rest period aka dormancy prior to that, so you have to count back another 8 weeks or so to the end of August--this is when the bulb needs to think that it is winter and go dormant.
For those of us in the Northern Hemisphere:
If you want holiday blooms the best way is to buy a bulb that has already been fooled for you.
If you want to fool last year's bulbs yourself, then you need to start simulating fall in July--decrease the daylength and temperature (and moisture) that your bulb gets, then create a dry winter in August, and spring in October.
To do this successfully, over and over again, such that the bulb creates enough energy for itself to bloom annually for the holidays, you actually have to create spring and summer--increasing temperature and daylength thru the fall and winter. Failure to artificially manipulate the entire growing season properly is what causes failure to rebloom for Christmas and frustration for those who try to fight mother nature.
(Personally, I'm not set up to flip/flop the seasons at my house
so for the amaryllis I keep year to year, I'm good with the bloom schedule they find for themselves --spring--under the conditions that they get.)