As frugal gardeners, we grow plants from seed in our basement during late winter and early spring. A $3 seed packet provides enough tomato plants for two to three seasons, plus plants to give away. And we grow a lot of tomatoes. If you consider the cost of purchasing pricey herb and perennial plants , the savings doubles. Gather your seeds, growing medium, and water. You’re almost on your way to an indoor garden.
But there’s still one thing missing. Light. Herein lies the frugal gardener’s dilemma: splurge on expensive grow lights or economize with basic shop lights?
In the past we’ve opted for the economy route. Our plants grew. It was nothing impressive. We planted extra for plants that didn’t make it. This year we tried something different and wound up with interesting results.
Light Needed by Plants
Outdoors, the sun amazingly provides all the colors of the spectrum. Plants soak up the red and blue colors with the most intensity. These colors allow them to photosynthesize, flower, and produce fruit. It keeps them growing in all their glory. Most indoor lighting produces a limited spectrum of colors and lower intensity of light. Intensity can be offset by allowing 15 – 18 hours of light. (A timer for the light works great for this.) But intensity doesn’t solve the color problem.
Lighting options abound, but the most common fall under two categories, fluorescent shop lights at $4 a bulb or fluorescent grow lights at $8 a bulb (both T12 bulbs). Standard shop lights provide only one end of the spectrum, usually the cool bluish colors. Grow lights mimic the suns full-spectrum more closely, providing cool through warm tones.
Economizing with Shop Lights
In the past, we used standard shop lights. After reading garden forums and seeing the price of grow lights, it just didn’t seem worth it. I also believed that since we were just growing seedlings, we could get buy with simple shop lights. Soon the plants would be outside under the full spectrum of lights. Let’s face it, we often start seeds indoors to save money so why buy expensive lights if I don’t need them.
Make no mistake, plants do grow under shop lights. Our plants grew. Some grew tall and spindly reaching for the light. It looked like they might snap with the slightest brush of a breeze. And some of them did. Other times, the plants grew slowly into short, sad little impostors. We compensated by planting more than we needed. But this required more space, more seeds, more potting mixture, more fertilizer, and more time. And that was just to increase our odds of having a decent garden. Suddenly, the economy version didn’t seem so economical.
After a lot of investigating, I believe there are a few things happening. First, I think our five year old T12 fluorescent bulbs had weakened in intensity. Apparently, the cheaper T12 bulbs we chose lose intensity over time. That would explain the legginess and stretching. Replacing the bulbs with newer lights, either shop lights or grow lights, would have fixed the “spindly-plant” problem.
However, with the grow lights all the seedlings are growing into lush and healthy plants. No sad, sickly short plants. Lighting with only cool spectrum colors can result in stunted growth. And overall, all the plants appear healthier and hardier. Our Thai basil even started flowering!
I’m happy with the results which I partially attribute to the full-spectrum lighting. But I I must admit other factors contributed to their improved vigor: adding new lights that haven’t faded in intensity, blowing a fan on the plants, and raising the temperature of the environment by enclosing it in plastic. Still, I believe the full-spectrum grow lights provide optimal indoor lighting conditions to grow healthy and resilient plants.
One last point: We are currently using cheaper T12 full spectrum bulbs. Next time, I would invest in the T8 bulbs. T8 bulbs cost more but would be worth the investment. Compared to T12 bulbs, T8 bulbs provide more intensity with less energy and don’t lose much of their intensity over time.
What type of lighting do you use to start indoor seedlings?