Expert: Christopher Littrell - 4/17/2010

Question
Hi! I was currently growing 8 cp's under 3, 15watt bulbs. I am new at this, but I now understand that growing them under these bulbs is like me eating less than 1 meal a day! But I am getting a 125watt compact fluorescent bulb, made specifically for plants. Is this enough for healthy growing?

THANK YOU

Answer
Hello Jordan,

First off, what kind of plants are you attempting to grow under artificial lighting? The species will impact the success of using artificial lights. Some species, like Venus Flytraps and Sarracenias, will require the equivalent of full sunlight like garden plants (such as roses, and tomatoes). Butterworts and Tropical Pitcher plants can be grown more easily under artificial lighting if it is intense enough and provides enough coverage.

A couple of small carnivorous plants of the tropical varieties might be fine under a single high intensity compact florescent light. A large plant, like a growing Nepenthes or a high intensity light plant, like a Venus Flytrap, are going to need something more advanced than a compact florescent bulb.

My setup for growing a collection of carnivorous plants (more than a handfull) indoors consists of six 40 watt twin mount florescent shop lights with cool white tubes in a side by side formation covering a 4 foot by approximately 4 foot area in front of a window for 16 hours a day. The plants are placed on shelves under the lights with a stairstep formation of shelves holding the plants varying distances from the lights according to the light needs of each species (basically about 5-15 inches). I am successfully growing a Purple Pitcher Plant and several flowering Venus Flytraps under that setup with no slowing in growth from flowering and with good purple coloration developing on the Sarracenia. That light setup is capable of growing a large number of small to medium sized plants or a few larger Nepenthes.

The reasoning as to why so many lights at a specific distance and length of time are needed is due to three factors. Intensity, photoperiod, and coverage area are three light needs of plants. Intensity can be ramped up with multiple lights adding lumen intensity all together in one area. Full sun would be about 40,000 to 50,000 lumens in most sunny areas of the planet. The light setup I have concentrates at least 20,000 to 25,000 lumens on one area (even though the total lumens would be over 36,000, not all of the lights in my setup are the same distance nor optimal placement for all of the plants). Since lumen intensity is not optimal, the plants will need longer daylengths of light to help make up for lower intensity. More lights over a large area helps as the plants will get light from many angles to help make up for lower intensity and odd leaf shapes. As always, turn the lights off at night for about 8 or so hours to give the plants rest so they can use the energy they produce and store by day. Florescent lighting is more natural in color or temperature of light spectrum, so is the best overall light to use. Plant specific lights (like grow bulbs and the like) are not really all that efficient compared to cost when you can simply buy a larger, inexpensive set of lights that provide more coverage and intensity of light for the plants your trying to grow.

Venus Flytraps and Sarracenias, along with other full sun temperate carnivorous plants, should always be grown outside in full sun all day long whenever possible for optimal growing.

Christopher