Grow Lights for Indoor Plants

Download (24.3 MB, 25 mins 34 secs)

Houston, we have a problem! We have spindly, weak leggy seedlings that are barely strong enough to hold themselves up! This will result in fragile plants that are susceptible to disease. Luckily, Houston Control has a simple solution. The cure for leggy seedlings is direct, long and low light, and the best way to achieve those conditions are introducing grow lights for indoor plants.  

This week I have been fielding some questions in various Facebook Groups about Starting Seeds Indoors, and some folks are having some trouble with leggy seedlings and wondering how to fix the problem.  In this post, video and podcast, I will discuss how I set up grow lights for indoor plants and starting seeds indoors. My stand supports my grow lights is simple, very stable and costs under $15.

What are Leggy Seedlings?

The picture above was from a failed experiment that I conducted in 2016. I germinated this group of tomato seedlings by putting a black tray on top of the tray with the soil, and after four days added light.  While I had good initial germination, you can see how “leggy” these seedlings were on Day 4.

Is is a problem because long, spindly (“leggy”) seedlings are more fragile than their stocky counterparts.  The do not hold up in windy conditions, and if you let them grow too tall, they will flop over under the weight of their own leaves.

Leggy seedlings are created by a lack of light.  The plants accelerate growth in order to reach the light, any light, in their growing area.  This can occur when a gardener plants seedlings and sets the container near a window or if the container is too crowded, and the seedlings are competing for light.

This is a common problem for gardeners who are trying to start seeds indoors.  You can correct this problem by adding an oscillating fan (tricking the plant by simulating wind) or adding grow lights for indoors plants.

Grow Lights for Indoor Plants

I recommend gardeners use grow lights for indoor plants unless you have a greenhouse that gets fantastic sun for 14-16 hours a day (which is one of my goals)!

As I mentioned in other articles, I use inexpensive grow lights from Menards. In Menards-speak, they call these T12’s “aquarium lights,” but technically they are Sylvania 40-watt T12 Gro-Lux Fluorescent Light Bulbs, and you can find them in the Electrical Department.

The lights cost around $10 per bulb, and I put them in inexpensive shop lights (the lowest cost ones I can find).  All in all, two bulbs and one shop light will cost you around $30, and that will be more than enough for two plug trays (or 188 plants if you use the plug trays I am using this year).

Grow Light Stand

When I first started growing seedlings inside, I used PVC pipes and fittings to build grow light stands in the past.  There was a problem using these kind of stands: I found that unless you cemented them together, they fell apart.  It is not ideal when your grow lights crash down on your tender seedlings!

I decided to use lessons learned from gardening in St. Louis Park when I hung the grow lights from the shelves.  I fabricated brackets that plugged into the pre-drilled holes in the shelving units, and then used PVC pipes with eye hooks to hang the lights over the seedlings with chains.  That simple system allowed me to adjust the height of the lights as the plants grew taller.  The problem with using the shelves is that it can get a little more difficult to do maintenance on plants and lights in the confined space (with a shelf above the lights).

I knew I had some wood in the garage, so I went foraging.  I found the 1″ PVC pipes with the eye hook holes from St. Louis Park (yay for not throwing these away)!  That was a win!  I also found a 4′ long 2×4 and a 2′ long 1×3.  I decided to make the grow light stand out of these boards.

Using these pieces of wood, I made the following parts using a skill saw and my trusty drill:

• 2 – 12″ base boards made out of 1×3’s
• 2 – 18″ vertical boards made out of 2×4’s
• 2 – 14″ horizontal boards made out of 2×4’s

Using screws I had on had, I put the two “sideways goalposts” together.  I added a “L” bracket to the 12″ base to give the stand more stability.  As you can see in the video, the grow light stand is very stable.

I added the two PVC pipes to the stand by using metal strapping typically used in plumbing projects.  I cut 4 6″ pieces and screwed them to the top of the stand.  Sliding the PVC pipes in, the whole stand got that much more stable.

The beauty of this system is that it is easy to construct, is inexpensive and can easily be moved if we have a project that requires using the workbench.

Putting It All Together – Grow Lights for Indoor Plants

The final stand – March 2018Gardeners get excited to start planting seeds in the Spring, especially after a long winter.  Sometimes we get ahead of ourselves and plant the seeds before we are ready. This can result in seeds popping through the soil and growing before we have adequate light for them.  The result are leggy seedlings that could collapse under their own weight!

To avoid leggy seedlings, you must do the following:

1. Add an oscillating fan to simulate wind and trigger the plants to thinken their stems
2. Add grow lights for indoor plants to provide direct, long and low light to your tender seedlings.

I have successfully used inexpensive Sylvania 40-watt T12 Gro-Lux Fluorescent Light Bulbs from Menards and have had excellent results.  I will have to try LED Grow Lights some day when I have some extra dollars in the budget, but this is working for me now.

To support the grow lights and shop light housing I constructed a simple stand consisting of PVC pipes, scrap wood, straps, some screws, eye hooks and two L brackets.  The grow light stand is stable, inexpensive and mobile.

If you are looking for a solution for your leggy seedlings, forage in your garage and head on over to a nearby big box store.

You can get very creative and provide ample light for indoors plants!

Let me know what you design and build.  I am really curious what designs you develop for your plants!