What Is UV Light

UV light, or ultraviolet light, is a form of electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. It is named ‘ultraviolet’ because it starts from the wavelengths just beyond the violet end of the visible light spectrum. The wavelengths of UV light range approximately between 10 and 400 nanometers (nm).

3 Types of UV Light

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UVA (Long-wave Ultraviolet A):

Wavelength: 320-400 nm

UVA makes up the majority of the UV light reaching the Earth's surface. It can penetrate deeper layers of the skin and is primarily responsible for skin aging and the formation of skin cancers. UVA is also used in black lights and tanning beds.

UVB (Medium-wave Ultraviolet B):

Wavelength: 280-320 nm

UVB is partially absorbed by the Earth’s atmosphere but is more energetic than UVA. It is responsible for sunburn, skin aging, and the development of skin cancers. It also plays a key role in the production of vitamin D in the skin.

UVC (Short-wave Ultraviolet C)

Wavelength: 200-280 nm

UVC is the most dangerous type of UV light, but it is almost entirely absorbed by the Earth's atmosphere and does not reach the surface. Normally, UVC is not applied to plant growth. 

Do Plants Need UV Light

The short answer is that plants do not necessarily need UV light to grow. What they need most during the plant life cycle is red and blue light. However, gardeners who implement UV lights for plants, particularly UVA and UVB light, are more likely to have robust stems, healthy foliage, and quality yields. 

To make it more clear, here’s a breakdown of what benefits UVA and UVB light bring. 

Benefits of UVA Light

• Morphological Development: Exposure to UVA light influences the morphology of plants, resulting in compact and sturdy growth, essential for crops and ornamental plants.
• Flavor and Color Enhancement: UVA light enhances the production of pigments, flavonoids, and antioxidants, improving the color, flavor, and nutritional value of plants.
• Pest Control: UVA serves as a natural deterrent to certain pests, reducing the dependency on chemical pesticides.
• Faster Photosynthesis: Studies have shown that exposure to UVA light can speed up the process of photosynthesis by around 12%, leading to increased growth, leaf size, and dry weight.

Benefits of UVB Light

• Stress Induction: Moderate exposure to UVB induces mild stress, stimulating the plant’s defense mechanisms and production of protective compounds.
• Increased Resilience: The induced stress enhances resilience against diseases, adverse weather conditions, and pests.
• Improved Flavor and Aroma: Stress-induced production of secondary metabolites enhances flavor and aroma in culinary herbs and crops.

So, plants can grow without UV light for sure, but they stand a bigger chance to grow well with UV light. 

What Is IR Light & Do Plants Need It

In addition to UV light, another subtle yet worth-mentioning light spectrum is IR light. Infrared light (700 nm–1 mm), as the name suggests, sits just beyond the red end of the visible spectrum. It’s divided into two categories:

• Near-IR (700–1100 nm): Closer to visible light, it interacts with plant photoreceptors.
• Far-IR (>1100 nm): Emits heat and is often used in thermal applications.

Do Plants Need IR Light

No, plants do not need IR light to grow. IR light doesn’t work as a fundamental lighting source for growing plants, but it does have its value:

• IR light can penetrate deeper into plant tissues, promoting stem growth and flowering. Additionally, IR light, when combined with far-red light, can trigger a shade avoidance response, accelerating stem growth.
• Proper use of IR light can quickly induce plants to enter the flowering stage or transition into a dormant phase. 

Do Grow Lights Have UV

Many modern grow lights, especially the advanced LED grow lights, come with the option of including UV light features. These grow lights often combine multiple growth light spectrums, including blue, red, UV, and IR, to ensure that plants receive the broad range of wavelengths they need for healthy growth.

However, if you’d like to implement additional UV and IR lights to upgrade the full growing experience, supplemental grow lights come as the best solution. Spider Farmer offers two sets of UV + IR supplemental grow light strips for delicate growers like you - UV30 & IR16 LED Grow Light Bars Set and UV60 & IR30 LED Grow Light Bars Set.