Microgreens do not need the same lighting intensity as fruiting indoor crops, so buying the most powerful fixture can be unnecessary. The key is even, repeatable coverage across the tray and a fixture that fits the shelf.
Coverage comes before wattage
University of Maryland Extension notes that fluorescent or LED grow lights can supplement or replace sunlight and uses about 16 hours of total daily light as a practical reference. They also note that fixture distance depends on intensity, with 6–12 inches above foliage as a typical range.
| Factor | What to ask |
|---|---|
| Coverage | Does the light illuminate the full tray evenly, including corners and edges? |
| Fixture shape | Does a bar, shop-light or panel shape match the shelf geometry? |
| Mounting | Can the fixture be raised, lowered and secured safely? |
| Heat | Will the fixture add unwanted heat to a compact shelf or room? |
| Power | How does one shelf scale into several shelves running daily? |
| Timer | Can the light run reliably on a timer or smart plug? |
One light or more than one?
Grower discussions frequently report that one centered fixture can create uneven growth or leaning on wider shelves, while two bars can improve coverage. The correct answer depends on shelf width and the fixture’s actual spread.
Start with the shelf, then choose the fixture
Measure the usable shelf width and height first. A light is only “good” if it fits the rack, gives the canopy even coverage and leaves enough room to work with trays.
Source: University of Maryland Extension; recent r/microgreens setup discussions.
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