Pepper plants need specific environmental (temperature and humidity) conditions to establish growth and create high yields. If the temperatures get too low it will stunt its growth or not produce blossoms, when the temperatures get too high the plant will drop it blossoms resulting in no or reduce yields.
The perfect temperature range for peppers is between 70 and 80 degrees F for Bell peppers and hot peppers can handle a little warmer temperatures up to 85 degrees. If their environment gets below 70 degrees the plants will struggle, which given even in August we don’t hit an average of 70 degrees F for any success a greenhouse, hot box, or a growbox is requirement. If you are a frequent reader of this site you probably already know I go with the last option.
With a few CFLs (or incandescent if extra heat is needed) the peppers plants are happy in the growbox. With exception of once a week watering with a diluted fertilizer at 50% recommended on the box they pretty much take care of themselves. If we do get a nice warm day I will bring them out for some natural light. This also invites some natural organic pest control of any aphids which may have found their way into the growbox. When the plants begin flowering this also gives some bees an opportunity to do a little pollination, this can be done by hand with a paint brush or Q-Tip though my success rate is much less than the bees, though they have been doing this for millions of years…I am still a little new at this
As mentioned above controlling the proper temperature is critical, I do this with a combination of computer controlled fans and lighting to maintain the proper temperature, though this could also be achieved by using a $10 outdoor digital thermometer and a occasional adjustments to venting or fan control to maintain a good temperature range.
Last year I only grew jalapeno pepper plants, but this year I am also trying Cayenne, Sweet Yellow, and Bhut Jolokia pepper plants. Though it is quite a bit more work growing peppers in my area, I like challenges and to do things that others say can not be done, call me stubborn.