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UV Light for Plants: Is It Necessary?

UV Light for Plants

Have you ever wondered which light affects the growth? In addition to common light spectrums that are visible to human eyes, there’s also invisible light that holds fair influence over the life processes of plants such as UV light. Do plants need UV light? Join us as we explore the radiant world of UV light for plants, uncovering its types, benefits, risks, and useful applications. 

Table of Contents

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

UV light can be categorized into three main types based on wavelength:

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. 

Should You Use UV Light for Plants

To your surprise, plants do not necessarily need UV lights to grow - what they need most during the plant life cycle is red and blue light. However, gardeners who opt for UV lights for plants 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. After reading it through, you can decide whether to use a UV plant light or not. 

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.

use UV lights to grow plants

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.

Best UV Lights for Plants Recommendation

Frankly speaking, though there are UVB grow lights on the market, it’s not necessary to buy an exclusive UV light for your plants, as plants require a more comprehensive light spectrum to grow. So how can you benefit from the UV wavelength without spending big money? Spider Farmer 40W UV & IR LED Grow Light Bar comes as the best solution. 

Spider Farmer 40W UV & IR LED Grow Light Bar

This light bar is designed to provide supplemental lighting to indoor plants with a targeted spectrum, including UV (365-420nm) and IR (730-745nm) wavelengths. With a power output of 40W, the light bar is designed to be energy-efficient, providing optimal light intensity with minimal energy consumption. You can freely install this light bar to existing indoor grow lights to offer optimal lighting conditions for indoor gardening. 


Now you should have a much clearer idea about the types and benefits of UV light for plants. Although UV light for plants is not a must-have, each spectrum brings about unique benefits, such as enhanced photosynthesis, improved flavor and aroma, increased resin production, and heightened defense mechanisms. If you are interested in fulfilling a more complete growth light spectrum for your plants, Spider Farmer 40W UV & IR LED Grow Light Bar is definitely your best option.


About Ciki

Ciki has been navigating the digital world of SEO for over 3 years, applying her expertise originally in the software sector before turning her attention to indoor gardening. Merging her tech-savvy background with a passion for nature, Ciki offers a unique perspective on gardening, blending modern techniques with time-honored traditions.

12 thoughts on “UV Light for Plants: Is It Necessary?

  1. Robert Franey says:

    I’ve purchased two SF 2000s just over a year ago.
    I absolutely love these lights.
    These lights make it possible to produce the most gorgeous plants no matter what I choose to be growing!!!
    I can’t wait to upgrade to a 4000 or greater !
    Thank you SPIDER FARMER

  2. Crystal says:

    I think the spectrum that your lights offer are truly impactful in the grow and look forward to playing more with uva and uvb

  3. Quentin says:

    Thank you so much for this amazing article! I am learning so much from your information!

  4. Jose Martinez says:

    I can´t wait to get my SE5000!!!

  5. Kevin says:

    Best grow decision I have ever made. Thought I was killing it then purchased a sf4000. No comparisons, the perfect light for 4×4 & 5×5

  6. dougbream says:

    I’m running an sf2000 paired with an sf1000 in a 2×4 and absolutely love the setup!! Thank for making lighting easy for a new grower!!

  7. stang1238 says:

    very nice

  8. Jereld says:

    I can’t wait to try out spider farmer and get away from these mars products.

  9. David says:

    Looking to start growing plants in a4x4x6ft tent not really sure of the best light needed or size needed. Looking for a little advise if possible.

    1. celia says:

      Dear customer, SF4000/SE7000 is a good choice for 4X4ft grow tent
      You can watch this video:

    2. Darrell aka Dee Bossman says:

      Yep, I am using the SE7000 and love it in my 4×4 tent. It fills every cm of the tent with god solid lighting. You won’t be sorry

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