Expert: Sarracenia Northwest - 5/12/2011

Question
Hi,

I am turning a 7x10' room into a lowland Nepenthes growing area and I have having some conflicting answers regarding lights. I have read where 40watt T12 bulbs work well but others sources say they are awful. I have also been directed towards the use of a 600 watt metal halide. Which I would like to upgrade to eventually, but I just don't see the need for it now since I don't have any plants yet. So do you think the 40 watt T12s will work? I was thinking of 2 fixtures above each growing table, maybe more if that is necessary.

Thanks

Answer
There's no single answer to this question.  It's sort of like asking different growers the soil recipe for Nepenthes.  You'll get a different answer each time.  To compound the matter, it also depends on the species of Nepenthes you plan to grow.  Size and species make a difference in your choice for lighting.

We use artificial lights with Nepenthes, but only as a supplement to natural sunlight.  The lights we use are T12, 40-watt tubes, and the lights are about a foot above the plants.  Again, this is only as a supplement to natural sunlight.  Our nursery is in Oregon, so we have lots of cloudy weather in winter.  Within a couple weeks, we will dismantle the lights and rely solely on sunlight.

T12 lights as the sole source are fine only if you are growing small, partial shade plants, such as ampullaria and bicalcarata.  These plants enjoy lots of dappled sunlight, and T12 mimics that type of lighting.  The lighting needs to be about 6-8 inches above the plants.  Other plants will do well under T12 provided that they are small.

If you plan to grow large plants, you will need to use either T5 lights or a 600 watt metal halide.  These lights produce much stronger lighting, which you'll need for very big plants.  The further away you move the lights, the weaker the lighting, so you need lights that will retain strength as it reaches the lower sections of your large plants.  Large plants would be anything that is more than a foot tall.  

Whether to get a metal halide or T5 depends a lot on your budget.  You'll get more bang for your buck with metal halide because of the light spread.  However, you will need to invest more in ventilation.  Your room will get hot!  T5 lights don't have the light spread as metal halide, but it is cooler, so you might get away with using a fan to dissipate the heat.  

Another factor is whether or not you're growing for personal or business purposes.  If personal, then start with small plants and T12 lights, and develop your skills as a grower.  You'll have more flexibility to adjust temperature and lighting than you would with T5 and metal halide.  If for business purposes, you'll need to weigh the cost against potential revenues from the plants you sell.

In the end, it's always a judgement call based on your plants, skills and wallet.  T12 uses less energy, but are best suited for small plants.  Metal halides and T5 use a lot of energy and spike your electric bill, but are useful for large plants.  

If you're still having difficulty deciding, always err in starting small and slowly.  Use T12 lights and grow small plants.  As your plants grow larger, you can invest in a T5 light.  When you have a large collection of plants, a metal halide would be appropriate.

Good growing!
Jacob Farin