Can You Grow Microgreens Without Natural Light?

Yes — microgreens can be grown entirely under artificial light, with no natural sunlight at all. In fact, for growers who want consistent results year-round or who live in flats with north-facing windows or basement apartments, artificial lighting is the better choice. Microgreens have modest light requirements compared to fruiting plants like tomatoes, and inexpensive, widely available artificial lights are more than capable of supporting excellent growth from sowing to harvest.

Why Artificial Light Works Well for Microgreens

Microgreens are harvested at an early seedling stage, before they begin the longer-term processes of flowering, fruiting and complex secondary compound production that require very high light intensities. They need enough light to convert from stored seed energy to photosynthetic energy — typically the cotyledon (seed leaf) stage — but they do not need the full solar intensity required to ripen a tomato or power a large houseplant through its growing season. This makes them ideal candidates for artificial lighting, where intensity is modest but consistent and controllable.

What Lights to Use

T5 fluorescent tubes (the long, thin tubes used in shop lighting and propagation shelving) are the most cost-effective starting point. A standard two-tube fixture covering a 60 cm span provides adequate light for one or two 10×20-inch trays. Mount the fixture 5 to 10 cm above the canopy and raise it as plants grow. Use a plug-in timer to run the light for 16 hours per day automatically.

LED grow strips and panels are increasingly affordable and are more energy-efficient than fluorescent options. Look for a full-spectrum panel rated at 2000 to 4000 lumens for a single tray — this is far more than enough for microgreens. Avoid purple/blurple LEDs that emit only red and blue light; full-spectrum white LEDs or tubes produce better-looking, healthier greens and are more pleasant to work around. Colour temperature of 5000 to 6500 K (daylight) is ideal.

Shelf Setup for Multiple Trays

A simple metal wire shelf unit with a grow light attached under each shelf is a practical, space-efficient system for growing multiple trays simultaneously. Each shelf holds 2 to 4 trays with a light strip or panel mounted to the underside of the shelf above. This creates a compact, stackable system where each tier is its own growing zone. Space shelves 40 to 60 cm apart to allow for tray height plus light distance.

Varieties That Thrive Under Artificial Light

Most microgreens do well under artificial light. Radish, broccoli, kale, sunflower, peas, mustard and amaranth all produce excellent results under T5 or LED grow lights. Basil benefits most from artificial light because natural light in most homes is rarely warm and bright enough for basil to germinate and grow reliably — a grow light with supplemental warmth from a heat mat is the ideal basil setup. The only variety to approach cautiously under low-power lights is wheatgrass, which grows more slowly at lower intensities but still produces a usable crop.

Electricity Cost

Running a T5 fluorescent fixture for 16 hours per day uses approximately 0.5 to 1 kWh per day depending on the fixture. At typical UK or US electricity rates, this is a few pence or cents per day — negligible relative to the cost of buying microgreens commercially. LED equivalents use 30 to 50% less power for the same light output.