Tips for Hanging a Grow Light in Your Closet

Turning a closet into a grow room is an ideal choice because it's secluded and out of the way. You are not wasting an entire room of your house for cultivation. Instead, you have set aside a small and sufficient space to practice indoor gardening. One of the first steps you’ll want to undertake for converting the space is to hang grow lights in your closet.

Tips on Hanging Grow Lights

Here are a few tips on hanging a grow light in your closet:

  • Grow lights must be adequately supported. Use a stud finder to locate a stud in the closet ceiling. Mark for a hole, then drill through the drywall and into the stud. You’ll be using a lighter grow light system that typically requires only light hangers, a chain or rope, and a hook from the ceiling.
  • Screw the hook through the hole. Apply steady pressure until the hook screws into the stud and is flush with the ceiling.
  • Find the areas on the grow light used for hanging, attach a chain, and hang it from the hook.
  • Consider attaching a rope/ratchet system and hang from that so you can easily adjust height. A cheaper alternative is to attach an S hook to the ceiling hook, or one at each hanger. You can then move the light up and down using the S hook and different loops on the chain.

Most closets are relatively small and will only provide sufficient room for about three adult plants but sometimes keeping things simple is best. The small space is easily tailored to support the plants at a fraction of the cost of large, more overwhelming areas of the home.

Choosing Lights for Your Grow Closet

The small closet space means heat is always a factor. Choose either HPS or LED grow lights.

LED grow lights: LEDs can be positioned closer to the plant without burning the foliage. Also, the cool LED lights will prevent the space from becoming excessively hot, so you won’t have to focus so intently on a ventilation system. Ideally, use only a full-spectrum LED light that will meet the needs of all of the growth cycles of the crop you are cultivating, eliminating the need to augment the fixture or change lights for flowering.

A simple 24W to 50W full-spectrum LED provides strong light, and it should have increased red light to improve flowering. It won’t generate much heat, so you won’t need a strong ventilation fan. If you are converting a large walk-in closet into a grow room, then you’ll need more light and possibly more fixtures, but for the average closet grow room, these are sufficient.

For more tips, read How Many LED Grow Lights DO I Need for My Grow Room?

HPS lights: In choosing wattage, consider the size of the closet:

  • 2 x 2 feet, 150 watts.
  • 3 x 3 feet, 400 watts.
  • 4 x 4 feet, 600 watts.
  • 5 x 5 feet, 1000 watts.

You’ll use more energy with HPS lights than with LEDs.

Height for Hanging LED Grow Lights

Position an LED light 24 to 26 inches above your plants during the seedling phase—the first three weeks of your plants’ life. When the plants enter the vegetative and flowering stages, move the LED grow light closer, to within 18 to 22 inches.

If you are using a premium LED grow light, you can sometimes get away with hanging the light a few inches higher. However, if the LED grow light lacks brightness, try hanging it a few inches closer.

Position a 150-watt HPS bulb 36 inches from the plant’s canopy to be safe in a grow closet.

Typically, when purchasing a grow light, it will list the manufacturer’s recommended hanging height, but these are only estimates and not always uniform. If the light does not come with any recommendations for hanging height, visit the manufacturer’s website to see their specifications.

Sometimes, you have to factor in the plants’ stage, such as vegetative or flower, plus exactly what you are growing to decide for the best acceptable height. With any plant cultivation, there is a lot of trial and error in finding your perfect solution.

Grow Light Hanging Hack

Most manufacturers don’t provide you with recommendations for hanging their lights in a closet, so you have to improvise. The small space means you will be working with only two or three plants, so you will want to reduce your height calculations by about 15 percent to curb the edge effect that occurs because of the high ratio of walls and smaller floor space in a cramped closet.

Light Uniformity in a Grow Closet

When growing a few plants in a small space like a grow closet, you’ll want to consider light uniformity because the cramped area can create shadows and if you are trying to grow two or three robust plants with a lot of foliage then you are going to need to ensure that light reaches the plant’s surfaces to promote even growth.

Benefits of light uniformity when hanging grow lights in a closet include:

  • Higher yields
  • Consistent and greater crop quality
  • Easier management of your time

Ideally, the walls within your grow closet should be painted a flat white so the light is reflected back on your plants. An alternative is to install reflective insulation that will reflect the light nicely to help create uniformity.

Using a Light Timer

One thing to invest in is a light timer which is ideal for the flowering time when your plants will be on a strict 12/12 light cycle. You don’t have to remember when to turn on and off the lights because the light timer will do all the work. They are inexpensive and easy to install at the same time you hang your grow lights.

Problems After Hanging Lights in a Grow Closet

Growing in a closet can encourage problems:

  • Sometimes plants grow too close to the grow light. You’ll need to either dim the lights or adjust the distance of the lights from the plants.
  • If the plant’s leaves start to curl upwards—rare with cool-running LEDs—the plant might be heat stressed. If so you’ll want to increase the distance between the plants and the lights.
  • Plants that start to stretch upwards and grow gangly are too far from the fixture and not receiving enough light, so the plants stretch upward to reach more intense light. If this happens, lower your grow lights. For every 12 inches between the plants and the light, the light intensity increases about 75 percent.

Add a Grow Tent

Although not absolutely necessary, placing a grow tent inside your closet solves a lot of problems. A grow tent will:

  • Trap the moisture inside the tent, preventing mold problems.
  • Provide a waterproof floor.
  • Provide hanging points for the light.
  • Include reflective walls, eliminating a need to paint the closet walls.
  • Come equipped with a properly sized light and fan if part of a package.

See the GrowersHouse grow tents page to shop for tents and grow tent packages, or to configure your own package.