Grow Spaces
Kratky Under Grow Lights
A grow light turns a shelf, closet or basement into a year-round grow space. Kratky containers fit under it with nothing else to plug in.
Why Add a Light
Windows run out of light in winter and in rooms that face the wrong way. A grow light gives you the same amount of light every day, so plants grow at a steady pace in any season. The Kratky container stays fully passive; the light is the only thing that needs power.
Choosing a Light
- LED: runs cool, uses little power and lasts a long time. Full-spectrum (white) LEDs are the easiest to live with in a home.
- Size: pick a light that covers the whole area of the shelf, not just the middle.
- Height: follow the maker's recommended distance. Too far and plants stretch; too close and leaves can bleach or scorch.
How Long to Run It
Leafy greens and herbs like long days. Many growers run lights for around 14 to 16 hours a day for greens. A plug-in timer makes this automatic. Give plants a dark period every day.
Where to Set Up
- Shelves: a light on each shelf of a wire or wooden unit makes the most of floor space.
- Closets: keep the door open sometimes, or add a small fan, so heat and humidity don't build up.
- Basements: often cool and stable, which suits lettuce. Check the containers don't sit on a cold floor in winter.
Containers Under Lights
Lights make algae worse if any light reaches the solution, so containers must be fully opaque. Leave space above each plant for growth, and raise the light as plants get taller.
Grow Light Checklist
- LED light sized to the shelf
- Timer set for long days, with a dark period
- Opaque containers
- Light height adjusted as plants grow
