It is generally not recommended that users grow hemp with ordinary lights. Unlike many other plants, hemp requires extremely high light to reach its full growth potential.
Since hemp is a sun-loving plant, the light intensity generated by some lamps cannot provide enough sunlight for hemp.
Incandescent light bulbs are also not suitable for growing lights for hemp because the light intensity is too low to meet the light needs of hemp during the growing season.
When the heat is too high, "light burn" may occur. If this issue is not addressed, mild burns can greatly reduce the potency and purity of hemp strains.
When the plant is too close to the light source, some users may notice the leaves of the plant turn an ugly yellow with brown or black edges.
As the plant grows, the terminal buds may turn an unhealthy white color. Both of these are warning signs that the hemp is being "lightly burned" by the grow lights.
For those new to home planting, it can often be difficult to tell the difference between a mild burn and a nitrogen deficiency. While both conditions can turn leaves yellow, we can probably tell them apart in two easy ways.
Firstly, mild burns usually affect the tops of hemp plants, while nitrogen deficiencies start at the bottom. Secondly, the leaves burned by the grow light are very brittle, but the leaves that are deficient in nitrogen are generally drooping.
Often all you need to do to fix a light burn is to move the grow light further away from the plant. If there is a lack of space in your growing area, you should use methods such as grow nets to restrain the hemp from continuing to grow taller, thereby distributing the light relatively evenly.
The main selling point of LED lights is that they produce powerful light spectrum without generating a lot of heat.
Depending on the LED plant grow lights the user purchases and uses, it may not be necessary to invest in a fan exhaust system (it is generally recommended when growing in a closed environment, so that the plants have adequate airflow).
Another advantage of LED plant grow lights is the simplicity of setup. Usually what a user has to do is to plug the LED grow light into an electrical outlet, hang it above the plant and turn on the device.
However, unlike fluorescent lights, LED plant grow lights are extremely potent on hemp at close range.
Therefore, when using LED plant grow lights, there needs to be enough distance to avoid damaging the hemp leaves. How much distance you need to leave depends on the intensity (power) of the LED light.
The most common plant grow lights for growing hemp today are full spectrum. The full spectrum has wavelengths in the visible light range of 400 to 700 nanometers (nm), which drives hemp photosynthesis.