Gardening Indoors with Grow Lights

This summer I grew several herbs, primarily basil. I grew them from seed, starting them off in my south-facing window. Then when the massive tree that dwarfs our house grew leaves, I moved them outside. First I put them in the backyard, but I eventually moved them to our only sunny spot - the sidewalk.

When fall came, the plants stopped growing. So I did a ton of research and bought a Hydrofarm 125 compact fluorescant light bulb with reflector (Hydrofarm FLC0125D). I grew my old plants for a while, but they were too old, woody, and infested with at least three pests (aphids, caterpillars, and something silvery was covering the leaves). So I threw everything out and started from scratch. Now I've got ZERO pests.

Currently I'm running two Hydrofarm 125s and growing 20 plants. I chosecompact fluorescant lights (cfls) over metal-halides (the leading competitor for indoor grow lights because they produce 100 lumens/watt, whereas cfl only does 70) for several reasons.


My Herb Pictures

1. Heat
CFLs produce far less heat. My 125 cfl bulb is much larger than a metal halide bulb, and metal halides are typically 400, 600 or 1000 watts. This also means less fire risk.

2. Compactness
I'm growing my plants on a shelf. I have two gardens that are roughly 18 inches by 12 inches. A 400 watt metal halide would be overkill.

3. Efficiency
By running 250 watts instead of 400, I'm saving electricity. As these grow lights are on 12-16 hours/day this is important. Another good thing about efficiency is that I'm growing them in my room during winter. As our house is poorly heated I am often running an electric heater in my room, so the heat produced by the grow lights is mostly not wasted.

To maximize the efficency of CFLs you have to grow your plants extremely close to the light bulb. Light output decreases exponentially (x^2) when you move away from the bulb. So I'm keeping my plants short and within 1-5 inches of the bulb. I'm hoping to keep my plants under six inches tall, because the bottom leaves will get very little light.

Even at 1 inch from the bulb, you are getting less lumens than sunlight (I bought a light metter to check). However, a plant has declining rates of return to sunlight - it won't produce five times as much in full sunlight (10,000 lumens) as it will in a grow light (where 2000 lumens is good). Thus my basil produces about as well inside as it did outside during the summer, when you include the cloudy days.

By keeping my plants so close to the bulb, I think I'm getting significantly better lumens/watt than I would with a metal halide (where I'd have to keep more distance to avoid burning the plants). The downside is that you have to micromanage the height of the light to maximize output.

LEDs are the latest development in advanced lighting technology, however they appear to be several years away from being the best solution. Once they are cheaper, more efficient, and perhaps when more research has been done regarding their output spectrum - then they might be the best solution. They are currently an excellent way of conserving energy. Eventually they'll be replacing cfls in household use, but that might be twenty years off. If you search the internet, you'll see a lot of hype around LED grow lights, but few of the larger hydroponics stores carry them.

As growing plants with lights uses a lot of electricity, I don't think it is a good idea (for the environment and your pocket book) to a grow a LOT of plants this way. Growing food in the summer is better.

I recently ordered the book: "Gardening Indoors: With Soil And Hydroponics", which I've started to read and highly recommend (both informative and great pictures).

"Gardening Indoors: With

"Gardening Indoors: With Soil And Hydroponics" is an EXCELLENT book. A comprehensive coverage of the hobby. The only thing lacking is the specific details on the plant you want to grow - which makes complete sense to get from another source as there are thousands or more of possible plants to grow.

In retrospect, now that it

In retrospect, now that it is summer it is very clear to me that growing things in sunlight is SO much better.