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Introduction to plant growth light

2021-05-21 14:04:58 0

When growing indoor plants indoors, the light intensity in the plant growth lights is a key factor that may affect the various stages of plant growth. However, under the plant growth light with various light source parameters, what is the optimal light intensity that plants use in each growth stage and therefore need? Or, how do we measure and adjust the plant growth light intensity to illuminate and grow plants effectively?

Plants illuminated by plant growth lights

What is the light intensity of the plant grow light?

Generally, the light intensity of the plant growth light refers to the amount of light generated by the light source to reach the plant, that is, the number of photons "feeding" to the plant (usually in lux or PPFD).

Lux (Lux) is a unit of measurement that describes the number of lumens in square feet or square meters that a photon falls on a surface. Taking a 1000 lumens light source as an example, if all these 1000 lumens are spread on a surface area of ​​1 square meter, the resulting illuminance is 1000 lux. However, when you distribute the illuminance or illuminance of the light source to 10 times the entire area, the illuminance or illuminance will be reduced to a less intense 100 lux.


How does light intensity help plants grow?

As we mentioned in the previous article, the light intensity of the plant growth light has a very important influence on the growth results. This is because high light intensity will burn plant tissues, and damage to plant tissues will significantly increase the risk of leaf deformation, partial rot and other problems. When the light intensity is insufficient, the photosynthesis and respiration of the plant cannot reach the same degree, so that the plant cannot grow. In this case, we must provide appropriate light intensity to meet the needs of plant growth and germination.

how does light intensity help plants grow?

How to measure the light intensity displayed by the plant grow light?

All green plants need light to grow, and the light intensity they need varies with the growth stage. For example, in the early stage of seedlings, they need a lot of light, but when they don't receive enough light intensity, they become small and elongated. But how do we measure the amount of light provided to plants?

By measuring the amount of light falling on the surface of plants, we can assess whether there is enough light for indoor plants to achieve maximum productivity. Measuring the intensity of light falling on a specific working surface simply requires a photometer with a sensor and a measurable illuminance reading.

How to adjust the light intensity of indoor plants to achieve maximum productivity?

After testing the light intensity, we will soon find that the light intensity drops rapidly when the light meter is removed from the light source. As we all know, this relationship between the light intensity and the distance to the light source is a law of physics, and the light intensity of each grow light behaves in the same way. In other words, we can easily adjust the light intensity by moving the plant grow light closer or away from the plant.

how high to hang your plant to grow?

Generally speaking, the closer the plant grow light is to the plant, the stronger the light felt by the plant. Therefore, the correct placement of the growth light is essential. Too close will burn indoor plants, while too far away means that plants cannot get the light needed for optimal photosynthesis. Therefore, in order to ensure that the plant growth light has the best light intensity, illuminate the plants and grow plants effectively, next, we give a suggestion that the grow light should be located in the best position.

Seedling stage

Planting lights should usually be installed between 24-36 inches above the plant canopy, depending on the power (wattage) of the light source. For most plants, it is generally recommended to place the grow light at the farthest position (36 inches) from the seedlings, as this can reduce the heat and light intensity and help prevent the seedlings from drying out. Once the root system is established and budding, the light can be moved closer (usually within the first 2-3 weeks).

For the plant growth stage

During the growth period, plants need stronger light for photosynthesis, so the plant growth light should be close to the plant (12-24 inches from the plant canopy) at this time.


During the flowering stage, as the height of the plant increases and the fruit grows, the demand for strong light will decrease. In this case, the distance between the top leaf and the light source is recommended to be between 18-24 inches to facilitate flowering. In addition, during the flowering process, there is generally no need to change the height of the light, especially when we do not need the plants to grow very tall.


Please contact us for more product knowledge of led plant grow light!

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