How to Grow Microgreens Indoors

Microgreens are among the best crops to grow entirely indoors. They do not require outdoor space, do not need pollination, are not affected by weather, and produce a harvest in 7 to 14 days regardless of the season outside. A small corner of a kitchen, a section of a utility room shelf, or a dedicated grow rack in any room with reasonable temperature will support a productive indoor microgreens system. Here is how to set one up well.

Choosing Your Indoor Space

The ideal indoor space for microgreens is warm (18 to 22°C), moderately humid (40 to 60% relative humidity is fine — standard home conditions), has some passive air circulation, and is close enough to a power outlet to run a grow light timer. A kitchen counter or dedicated kitchen shelf is convenient for daily watering and monitoring. A utility room, spare room or even a wardrobe can work well if you add a grow light and ensure the space does not drop below 16°C at night.

Avoid locations directly above or adjacent to heat sources that produce significant dry heat (a radiator blasting at close range will dehydrate your trays quickly). Also avoid locations with dramatic temperature swings between day and night — a south-facing conservatory that bakes in summer and freezes in winter is a poor year-round choice.

Shelving for Multiple Trays

A simple wire-frame metal shelving unit (the kind sold for garage or kitchen storage) is an ideal microgreens rack. The open wire design allows airflow between trays and the shelves can be positioned at whatever spacing you need. Mount a grow light strip under each shelf, pointing downward to illuminate the tray on the shelf below. This gives you a stacked system where 4 to 6 shelves can support 8 to 12 trays simultaneously — all in the footprint of a small bookcase (typically 60×30 cm floor space).

Light in an Indoor Setup

An indoor setup almost always benefits from artificial lighting rather than window light alone. Window light in most homes is directional, seasonal and inconsistent. A grow light run on a 16-hours-on/8-hours-off timer provides predictable, even light regardless of weather or season. LED grow strips or panels mounted under each shelf at 5 to 10 cm above the canopy are the standard solution. Timer outlets are inexpensive and essential — manually switching lights on and off every day is impractical long-term.

Maintaining Hygiene in an Indoor Space

An indoor growing space requires regular cleaning to prevent mould spores and fungus gnats from establishing. After each tray cycle, clean the shelf surface with a dilute bleach or hydrogen peroxide solution. Remove spent medium and root mats promptly rather than letting them sit. If fungus gnats appear (small flies hovering around the trays), they are attracted to moist organic matter — ensure spent trays are removed immediately and the growing area floor is clean and dry.

Water Management Indoors

Bottom-watering is particularly important in an indoor setup because it keeps surfaces dry and reduces the risk of mould and gnat activity. Have a jug or watering can nearby and a designated area (over a sink or on a waterproof mat) where you can fill and drain the reservoir tray without making a mess. With 6 to 8 trays in rotation, daily watering takes about 5 to 10 minutes — a manageable task that also gives you a daily opportunity to inspect each tray for problems.