Lighting for overwintering tropical plants indoors

Q: Days are getting shorter and darker... I brought my tropical plants indoors for overwintering (I live in Atlanta, GA). Could you give me some advice on what lamps should I use for additional lighting of my plants?

A: Indoor plants are very unlucky: they have to grow in "caves," and everybody knows that plants don't grow in the caves. The luckiest plants win sunny windowsills, but even there they dwell rather like in underbrush under tall trees, where the sun illuminate them only early in the morning or in the evening, and its light is diffused by foliage.
Usually domestic plants are in desperate lack of illumination not only in winter, but also in summer. No light - no growth, no flowering. So, plants need extra light to compensate the lack of illumination in the "room-cave" conditions.
Before you will start any practical actions to help your plants, you need first to decide whether you are going to set an additional illumination, or provide full lamplight. In the case of just additional illumination, rather inexpensive luminescent lamps will do, and you don't have to think about their spectrum. Continue reading...