When attempting to grow vegetables indoors or to start plants from seed, natural light isn’t always enough, especially in colder climates or seasons. Though some houseplants can survive in low lighting conditions, others need added light from grow lights.
Light-emitting diode (LED) grow lights are the go-to pick for many home gardeners, because they’re energy-efficient and eco-friendly options, and they can produce full-spectrum light. LED grow lights are different from the standard LED bulbs such as those used in home light fixtures. Read on to learn more about how to choose the best LED grow lights for your home.
Types of LED Grow Lights
LED grow lights come in a variety of forms. Learning about the most popular ones can help you choose a suitable type for your indoor garden.
Spread-Style
Spread-style LED lights have many small individual lights spread out over their entire surface area, which makes them effective in providing light to a large number of plants. The two main subcategories of spread lights are spider-style and quantum board.
Quantum board led grow lights use a large number of small LED grow lights spread out over a relatively large, flat surface area. They use full-spectrum white LED diodes and typically feature passive cooling, allowing the plants to be placed immediately under them without the danger of too much heat emission.
Spider-style lights feature multiple LEDs on narrow “arms” in an open bar design rather than on a solid board. These tend to be more expensive than quantum board lights.
Chip on Board (COB)
COB led grow lights feature a number of tiny LEDs placed close together on a single chip, resulting in a single powerful point of light. While the center point of the area they cover receives optimal lighting, they don’t offer the same level of widespread, equal coverage as spread-style LEDs.
Since they’re so powerful, COB lights often emit more heat than other types of LEDs and may require the use of fans to cool down the area. They use full-spectrum white LED diodes and provide deeper canopy penetration than spread-style LEDs.
Traditional
Traditional LED grow lamps are usually compact, making them a good choice for small spaces. They use LEDs that provide medium power and typically feature multicolored LEDs that cover the full spectrum of color frequencies, unlike white LEDs. This gives their light a colorful appearance that indoor growers might or might not like.
What to Consider When Choosing the Best LED Grow Lights
The following sections detail some of the most important qualities to keep in mind when shopping for the best LED grow lights for your needs.
Light Spectrum
Natural sunlight features all the colors on the electromagnetic spectrum. Some LED lights can reproduce only certain color frequencies, while full-spectrum white LED lights produce all the hues necessary for every stage of the growing process.
Blue light helps plants grow in the earliest stages of their lives. It’s the first color plants can absorb in their vegetative state.
Purple light is also used in the vegetative state; however, it’s not as effective for photosynthesis as blue light.
Red light helps in the latter stages of growing and is essential for buds to flower.
White light encompasses all the colors of the spectrum. Used alone, it can be effective for every developmental stage.
Power
It’s a bit difficult to compare LED grow lights because manufacturers use a variety of metrics to measure the power of their lights and the amount of light they emit. The brightness of LED lights is measured in lumens. Seedlings require approximately 2,000 lumens per square foot to thrive, while flowering plants may need as much as 10,000 lumens.
While lumens measure visible light, biologists often use photosynthetic photon flux (PPF) or photosynthetic photon flux density (PPFD) to measure light intensity in terms of the light that indoor plants will actually absorb. PPF is measured in μmol/second (or micromoles per second), which is the number of photons of light emitted every second. PPFD is also measured in micromole/m2/s and measures the density of light distributed per square meter per second. The higher the PPF and PPFD, the more effective the light should be.
Heat Output
One of the risks when using a grow light is that the heat emitted by the bulbs can damage your plants. However, LED lights give off very little heat relative to the amount of light they produce. But they do produce some heat, so many models are equipped with built-in cooling systems to ensure proper temperature regulation.
Some LED lights have aluminum heat sinks, and others come equipped with fans. A unit with a fan might be loud, so factor noise level into your choice when selecting a grow light.
Coverage and Wattage
To choose the right plant grow light, you’ll first need to establish how much coverage you need. To do this, group the plants together and measure the square footage they take up. Most grow lights will clearly list the coverage they provide.
To establish how much electricity a light uses, look for its “actual power draw” or “actual power consumption.” This is measured in watts and gives a good indication of the light’s power. Bulb wattage is not a good indicator because LEDs are designed to be energy efficient.
Connectivity
Many LED grow lights are designed to link to other units to cover larger areas, which is typically referred to as “daisy-chain connectivity.” Products with this capability simply plug into each other and then plug into one outlet, which minimizes the number of cords required for setup.