Congratulations if you have decided to adopt LED lighting for your greenhouse. You’re choosing an energy-efficient lighting option that creates a better environment for your plants. However, choosing the right LED light fixture for your greenhouse can be a daunting task — especially if you’re new to LED lighting.

How far should the LED grow lights be from the plants?

A common misconception about LEDs is hanging height. LED grow lights can be placed as close as 6 inches above the tree canopy. However, HPS lights emit a lot of heat and must be hung away from the tree canopy to avoid burning the plants. Before purchasing grow lights, compare the difference in operating costs between LED and HPS.

LED lights are more energy efficient and generate much less heat than HPS lights. This advantage allows LED grow lights to be hung closer to the plants for higher PPFD without causing damage.

Avoid hanging LEDs 18–24 inches above the plant canopy. As the light dissipates before reaching the plant, the optical density decreases significantly. Designed to hang LED lights 10–12 inches above the canopy. You can get as close as 6" to maximize PPFD (if you have proper CO2 and ventilation).

It is important to monitor your plants and understand how they respond to increased light levels. Lower or raise the height of the LED grow lights as needed to avoid any stress on the plants.

ECO Farm SP-800 Samsung Foldable Dimmable Full Spectrum LED Grow Light

Features:

This ECO Farm LED grow light uses 2176 pcs high efficient Samsung LM281B leds, boast the market-leading efficiency to 2.8 µmol/J and 2.5g yield per wattage with 30% higher Average PPFD, the actual power is 840 watt, it can cover 7x7ft growing area in Veg stage and 6x6ft for flower stage; Newest SMD LED technology to provide light output PPFD up to 2345 μmol/㎡s, high energy efficiency at 2.8umol/J.The best solution is to get more and better quality fruits. The light intensity can be changed by a dimmer knob according to the different growth stages of plants. With a 180°folding design, the angle and range of light can be adjusted appropriately and storage space-saving. One will meet all your needs.

Mars Hydro FC 8000 LM301H LED Grow Light

Features:

The Mars Hydro LED Grow Light is designed and engineered with commercial cultivators in mind, but is also perfect for nearly any personal grow. This powerful light delivers impressive results with an average uniform PPFD of 1500 μmol/s, sufficient to activate 100% photosynthesis and achieve maximum yield with or without CO2. The FC 8000 is the ideal light for almost any indoor growing scene, including single- or multi-shelf vertical farms, thanks to its versatile design and Samsung LM301B diodes for stronger canopy penetration and more consistent output. The FC 8000 LED Grow Light provides uniform standard readings thanks to an excellent 12-band spectrum, including IR, for maximum photosynthetic response. With enhanced blue and red light, plant growth increases with higher yields, larger flowers, and a more potent, higher-quality end product.

Mammoth Lighting Fold Series MF08 LED Grow Light

Features:

The Mammoth LED grow lights are built with high-quality Samsung diodes. The lights encompass a continuous range of wavelength from blue and green to red, creating a light blend matching the natural sunlight. 469 Samsung LM301B diodes per bar delivers the industry’s Highest PPFD and Yield. Mammoth customized their light spectrum to optimize plant growth and increase yields while consuming less energy and reducing operating costs compared with traditional horticulture technologies. With a proprietary blend of 3000k+5000k+660nm+730nm, for full cycle growth. 730nm speeds up flower (~5 days) and adds up to 5% more yield. Up to 5x5 flower coverage, 7x7 veg coverage. Strategically designed bars/spacing delivering more even lighting coverage (and growth) over a 5'x5'.

How Much Light Does a Plant Need?

Each plant is diverse and has unique light needs. It is important not to leave your bulb on for more than 24 hours, as this may cause it to overheat and break. Here, we have mentioned a few plants and their light needs to help you figure out when to turn off your grow light bulb.

Short-day plants
These plants can survive with fewer than 12 hours of light per day. A few examples of these plants are potted flowers like chrysanthemums, begonias, kalanchoes, and azaleas. These plants need even less light before setting buds and blooms.

Long-day plants
These plants need 14 to 18 hours of daylight each day. This category includes the majority of flower and vegetable seeds for gardens. These flowers typically turn pale and lanky if they don’t receive enough light.

Day-neutral plants
These plants can survive on 8 to 12 hours of light every single day. Their light needs do not change with seasons and remain the same throughout the year. This group of plants includes African violets, coleus, and foliage plants.

Why are grow lights necessary for greenhouses?

It comes as no surprise that plants can’t grow without light. Plants need light to photosynthesize, which allows them to convert light, oxygen, and water into energy needed to grow and develop.

But not all light is created equal. The chlorophyll in plants is responsive to particular wavelengths of light, absorbing the maximum light when exposed to red and blue lights, or light in the range of 400–700 nm. Green light, roughly in the middle of this spectrum, is not as easily absorbed, but this allows it to penetrate deeper into leaf tissues.

We don’t recommend using household light bulbs to grow your plants. While incandescent light bulbs are cheap and provide a continuous light spectrum, they would need to be placed far from plants as they can emit too much heat and burn leaves. Furthermore, the average lifespan of around 1,000 hours makes them highly inefficient.

Grow lights are specifically designed to meet the light spectrum needs of plants for all stages of growth, making them the most efficient choice for the greenhouse grower. Whether you’re starting seedlings or hoping to grow fruits and vegetables throughout the winter, grow lights are a must-have greenhouse accessory.

Conclusion

LEDs offer a full spectrum and are so versatile that they can be installed in almost any indoor planter. They are a good first investment for first-time growers. LEDs last longer, produce higher yields and are of higher quality. The money spent will be the money saved on repairs and replacements.