Written By Lara Wadsworth

Microgreens are one of the easiest and most rewarding indoor crops to grow. They are easily grown by anyone in any situation, and they are absolutely packed with nutrition and flavor. You can harvest them in 2 weeks or less, which will result in a major upgrade to your diet. However, in my experience, if there is one thing that microgreens growers get wrong (whether you’re seasoned or a beginner), it is light.

The right lighting setup is critical if you want your microgreens to live up to their potential. While it is easy to get this step right, it is also important to remember that not all lights are created equal. Between all the horticulture lighting-specific terminology and the wide array of prices, one can often feel overwhelmed and lost. I’m here to guide you through everything you need to know in order to choose the right setup for your life, plants, and budget.

Key Features to Look for in Microgreens Grow Lights

• Full Spectrum: This refers to the light spectrum. In other words, a light that is labeled as “full spectrum” mimics natural sunlight and includes both blue and red wavelengths. This is beneficial because blue light promotes leafy growth, while red light enhances stem strength.
• PPFD: This stands for Photosynthetic Photo Flux Density. In short, this is a measurement of how much usable light reaches your plants. For microgreens, look for something that lands between 200-400µmol/m²/s. This range will ensure the lights are strong enough to support good vegetative growth without causing burning or scalding.
• Photoperiod: Microgreens thrive on about 12-16 hours of light each day, followed by a period of rest (darkness). This term is not necessarily relevant when choosing a light, but it is critical to understand when using your chosen light.
• Heat Output: Microgreens are delicate and can easily be harmed by too much heat. Having a high heat output can dry out trays and cause leaf burn or stress. Choose a light with low heat output.
• PAR: Photosynthetic Active Radiation (PAR) refers to the range of photons that a light puts out. All you need to know is that you want 400-700nm. This is the optimal range for photosynthesis.
• PBAR: This stands for Plant Biologically Active Radiation. This refers to a greater range of light wavelengths than PAR. For microgreens, PAR is the priority, but PBAR can sometimes give extra benefits in flavor or appearance.
• PPF: Photosynthetic Photon Flux (PPF) measures how many PAR photons a light emits per second. Think of it as the total amount of “plant-usable light” coming out of the fixture. A higher PPF means more potential growth power.
• PPE: This stands for Photosynthetic Photon Efficacy and measures how efficiently a grow light turns electricity into usable light. For microgreens, a PPE of 2.0 µmol/J or higher is a sign of an efficient, modern LED fixture.
• DLI: Daily Light Integrating (DLI) is the measurement of the total amount of light your plants receive over a day. It’s essentially PPFD multiplied by the number of hours of light. Microgreens do well with a DLI of 12-16 moles of light per square meter per day.

The Bottom Line - For growing microgreens, look for a full-spectrum LED grow light with a high PPE (2.0+ µmol/J), strong PPFD (200-400 µmol/m²/s at tray height), and low heat output. Add in a timer for 12-16 hours of light per day, and you’ll have everything you need for consistent, flavorful harvests.

Types of Grow Lights for Microgreens (Pros & Cons)

All lighting options for plants fall into three categories: Natural, Fluorescent/incandescent, and LED.

Natural Sunlight

Pros: Free, abundant (most of the time), and provides the full spectrum needed for plant growth.

Cons: Inconsistent and varies with seasons and weather patterns, as well as window direction. Sunlight is not controlled or steady enough for effective microgreen production indoors.

Fluorescent or Incandescent Bulbs

Pros: Affordable and easily accessible. Fluorescent lights were once the industry standard.

Cons: Incandescent bulbs emit a lot of heat and a wide range of light wavelengths that are not useful to plants, making them overall less energy efficient. Fluorescents are marginally better but are weaker compared to other options.

LEDs

Pros: The most energy-efficient option. They also last the longest and put out the least amount of heat. They are highly adjustable and can be tailored to your specific plants’ needs.

Cons: The highest upfront cost.

Best Grow Lights for Microgreens: Top 3 Picks

How to Set Up Grow Lights for Microgreens (Step-by-Step)

1. Positioning - Keep lights 6–12 inches above trays. Any closer and your seedling will scorch. Any farther and the sprouts will stretch and get leggy.
2. Timing - Use a timer set for 12–16 hours daily. This way, you won’t have to remember to turn the light on and off each day. It will save you money and ensure your sprouts get their much-needed dark period.
3. Humidity Dome - Microgreens germinate best in darkness with a humidity dome or tray cover. As soon as the seedlings sprout, remove the lid and turn on the light.

Frequently Asked Questions (FAQ)

Do microgreens need special grow lights?

Yes, while they can grow in sunlight, LED grow lights provide consistent, controlled light that prevents legginess and improves yields.

What is the best light spectrum for microgreens?

A full spectrum LED (400–700 nm) mimics natural sunlight and ensures optimal growth and color.

How many hours of light do microgreens need?

Between 12–16 hours per day, followed by a dark rest period for recovery.

Lighting can feel like a technical detail, but it’s one of the biggest upgrades you can make to improve your microgreen harvest. The right light prevents legginess, enhances color, and can even improve the nutritional benefits of your crops. With this information, you can make the right choice and keep growing year-round!

Lara Wadsworth, True Leaf Market Writer