Gardening Under Lights: Light for Propagating & Growing Tiny Plants

Tiny Terrariums Under Grow Lights

How much light for tiny plants?

I have many different grow light set ups around my home. Here is one of my vegetative propagation and new transplant areas under lights- I use a 4-lamp T5 fixture with only one HOT5 fluorescent lamp inserted, or LED bar, for lower light cuttings and species that are rooting in. New vegetative cuttings do not need as much light as actively rooted and growing plants.

Directly under the lamp the plants with some active root growth are getting a DLI of about 5 umol/m2/day (measured with quantum flux meter and PPFD), which puts the output in a shade/heavy shade low-light category - which is perfect for cuttings or other low light species that are transitioning.

At the edge of the fixture and the lamp, it’s about a 2.5-3 umol/m2/day DLI for cuttings with no roots yet. Lamps is on for 12-hrs. Some of the species here include sinningia, begonia, masdevallia, peperomia, etc. and some new barefoot lithops just potted up (which should be in a shaded area for a week or two).