LED greenhouse grow lights provide plants with the necessary light for healthy growth when sunlight is insufficient. So, do you need one? Read on to find out.
Are LED Greenhouse Grow Lights Necessary?
A greenhouse provides a protective environment for plants, shielding them from adverse weather conditions such as wind, rain, cold temperatures, and potential damage from animals and pests. It offers a viable option for beginners, experienced gardeners, and anyone who wants to cultivate plants outside their normal growing season.
For plants to thrive, light is crucial as it enables photosynthesis, the process through which plants produce chemical energy for growth. However, there are situations where accessing direct sunlight becomes challenging:
- In regions with limited sunlight, such as areas with long winters, the greenhouse may not receive sufficient natural light for plant growth.
- Limited garden space may force the greenhouse to be positioned in an area that lacks direct sunlight.
- The presence of numerous trees in the backyard or garden can obstruct sunlight from reaching the greenhouse.
In such cases, the installation of greenhouse grow lights becomes helpful and beneficial. These lights ensure that plants receive the necessary light for photosynthesis, promoting healthier growth and increased disease resistance.
On the other hand, there may be instances where the greenhouse receives excessive sunlight. To address this, using a shade cloth or applying shade paint can help regulate the amount of sunlight reaching the plants, preventing potential damage caused by excessive heat and light exposure.
What Are the Types of Greenhouse Grow Lights?
Incandescent Greenhouse Lights
Incandescent greenhouse lights are a type of electric lighting that emits visible light by heating up to high temperatures. Do not place them near plants because of the excessive heat they generate. While they can be easily installed, using incandescent bulbs is not recommended.
Fluorescent Greenhouse Lights
T5 lights are a type of full-spectrum fluorescent lights that distribute light along the length of the lighting. This feature ensures uniform growth in younger plants, eliminating the need for rotation as required by other light sources like HID (high-intensity discharge) lights.
However, unlike LED and HID lights, fluorescent lights can’t penetrate deep into the plant canopy to promote flowering and fruiting. Nevertheless, they are readily available and more affordable compared with other types of grow lights.
The light produced by fluorescent lights is directed downward, making them less suitable for larger areas. They are more effective when used as a supplemental light source, in contrast to other light sources that can be employed all year in a greenhouse located in a shaded area.
High-Intensity Discharge Greenhouse Lights
HID lighting is a popular choice among greenhouse farmers due to its affordability and high light intensity. It is considered an efficient option for supplemental greenhouse lighting because of its ability to convert power into light effectively.
There are two varieties of HID lighting commonly used in greenhouses:
- High-Pressure Sodium (HPS) Greenhouse Lights
HPS bulbs emit light in the red spectrum, which promotes growth and flowering in plants. They are often used to extend the photosynthetic day when plants already receive sufficient natural light. HPS bulbs are more efficient than metal halide bulbs in converting power into light energy.
However, using HPS lights in a greenhouse may lead to increased cooling requirements, potentially raising operational costs. Besides, HPS lights have limited dimming capabilities to adjust light intensity.
- Metal Halide (MH) Greenhouse Lights
MH lights emit more blue light, making them ideal for vegetative growth. Their spectrum is more balanced compared with HPS bulbs. Greenhouse growers commonly use MH bulbs during the early stages of plant growth.
Light-Emitting Diode (LED) Greenhouse Lights
LED grow lights have gained popularity due to advancements in LED technology. LED lights offer a notable advantage in their compact size, typically only a few inches in diameter, which makes them easy to mount.
Many growers prefer LED lights because they consume significantly less energy compared with HPS lights while still providing equivalent output. Additionally, LED lights use less energy since they produce significantly less heat than HPS lights.
Scientific research shows that plants respond well to specific wavelengths of light. With LED lights, growers can adjust blue and red light to achieve these desired wavelengths. LED lights also offer a dimming capability ranging from 0% to 100%, providing full control over light intensity. This feature allows growers to meet the exact needs of their various plants.
Irrespective of the type of grow light being used, it is crucial to have a reliable suspension system in place that enables easy adjustment of the light’s height as plants grow. Additionally, make sure the purchased suspension system has a weight rating suitable for the specific lights being used.
How Long Should You Leave LED Greenhouse Grow Lights on?
While light is crucial for plant growth, it’s important to note that plants also require periods of darkness for various chemical processes to take place. Therefore, keeping greenhouse grow lights on continuously for 24 hours is unnecessary, even harmful. To regulate the duration of light exposure, it is recommended to install a timer for controlling the operation of the grow lights.
Plants can be classified into three groups based on their daily light requirements.
Short-day plants, such as azaleas and begonias, require approximately 12 hours or less of light to stimulate blooming. Excessive light can actually be detrimental to these plants. If you are growing these types of plants in a greenhouse with sufficient sunlight exposure, it may not be necessary to install additional grow lights.
long-day plants, including most vegetables and garden flowers, need around 16 to 18 hours of light exposure for optimal growth, particularly during the seedling stage.
Day-neutral plants, such as foliage plants and geraniums, have a consistent light requirement of 8 to 12 hours throughout the year. For such plants, it may be necessary to switch on the greenhouse grow lights only during shorter daylight periods, such as in winter when the greenhouse has limited access to sunlight.
How Far to Place LED Greenhouse Grow Lights from Plants?
Not all grow lights are equal in terms of wattage and efficiency. Higher-wattage grow lights are generally more powerful and emit more light, but LED lights are known for their efficiency even at lower wattages. The displayed wattage of LED greenhouse grow lights can provide guidance on the appropriate distance between the light and plants.
The following is for your reference.
- 100W= 8 -12 inches away
- 200- 399 W = 12- 20 inches away
- 400- 599 W= 20- 30 inches away
- 600+ W = 30+ inches away
It is vital to monitor your plants at various distances to achieve the best results. If a plant appears leggy or leans toward the light source, it indicates that you should move the grow light closer. Conversely, if you observe leaf burn or bleaching, it suggests that the grow light needs to be positioned farther away from the plants.
What to Look for in LED Greenhouse Grow Lights?
In addition to the type of light bulb, there are several other essential factors to consider when selecting greenhouse grow lights. While there are numerous grow light products available, not all of them can meet the specific requirements of a greenhouse setting.
Greenhouse grow lights need to last a long time, be energy-efficient, and cover more areas than grow lights for indoor plants. Additionally, grow lights for greenhouses should be able to be used singly or daisy-chained together to quickly and effectively cover larger areas.
Selecting waterproof grow lights for the greenhouse is crucial due to frequent watering and high humidity levels. Improperly sealed grow lights can malfunction when exposed to excessive moisture.
Fortunately, there are grow lights available that are specifically designed for use in greenhouses and are either waterproof or highly water-resistant. It is important to carefully review the product descriptions and look for keywords indicating waterproof capabilities and the ability to withstand high moisture levels.
When choosing grow lights, it’s crucial to take the coverage area into account, especially if you need to illuminate your entire greenhouse or a number of shelving units.
Wattage is generally a useful indicator of how much area a grow light can cover, but it is not a one-size-fits-all measure. Higher wattage generally suggests that a grow light can cover a wider area, even from a further distance to the plant. However, higher wattage does not mean better, excessive light exposure can potentially harm plants.
LED lights operate with greater efficiency compared with traditional grow lights, allowing for the same amount of light output with fewer watts. Manufacturers often differentiate between displayed and actual wattage for this reason. For example, a single LED grow light may use 25 actual watts but emit light equivalent to a 50W HPS light. Both lights are capable of producing sufficient light for approximately 1 square foot, but the LED light does so more efficiently.
Choose LED Greenhouse Grow Lights at MokoLight
For our LED lighting solutions, we’ve partnered with Samsung, Osram, Philips, MEAN WELL, etc., to provide our clients with world-class LED greenhouse grow lights. Clients around the globe speak very highly of us for our fast shipping, lower price and prompt services. For further information or support, feel free to contact us.