Distance from the window

Distance from a window matters as much as its direction. Light falls away quickly as you move into a room, so a plant a few steps back can receive a small fraction of what a plant on the sill gets.

Mississippi State University Extension notes that light intensity can drop from about 1,000 to 100 foot-candles within just a few feet of a window. Illinois Extension gives a similar picture: directly in front of a south window counts as direct light, while 15 to 20 feet back from the same window counts as low light.

This is why a plant can struggle in a room that seems bright. When a label says 'bright indirect light', it means a spot within a few feet of a bright window where the sun's rays are filtered, for example by a sheer curtain or blinds.

Moving a plant closer to the window is often the simplest fix for too little light. Closer can also mean direct sun, though, so move in steps and watch for pale or scorched patches.