Quick answer
Microgreens get leggy, meaning tall, pale and floppy, mainly because they are not getting enough light, the light is too far away, or they stayed in blackout too long. Warm temperatures and overcrowding make it worse. Lower your light, give 12–16 hours a day and uncover trays as soon as most seeds have sprouted.
Leggy microgreens stretch toward the light, fall over and taste watery. The fix is usually simple.
The 5 most common causes
- Not enough light. A dim window or weak bulb can’t keep up.
- Light too far away. Even a good light loses intensity quickly with distance.
- Blackout too long. Seedlings kept in the dark keep stretching.
- Too warm. High temperatures speed up stem growth.
- Overcrowding. Seedlings compete for light and grow upward.
How to fix leggy microgreens
- Lower the light toward the tray (see how high to hang grow lights).
- Run lights 12–16 hours a day on a timer.
- Uncover trays as soon as most seeds have sprouted and lifted their covers.
- Keep the room comfortably cool, around 65–75°F (18–24°C).
