If you’ve got herbs or geraniums spending the cold months on indoor windowsills, here’s a little trick that’ll help them out this time of year. Line the sills with aluminum foil, shiny side up. It’ll reflect light onto the plants and keep them going strong. To increase the light level even more, cover a piece of cardboard with foil, and hang it on a wall opposite the windowsill, so that it reflects the sunlight onto your potted plants. Besides boosting their growth, it’ll keep them evenly shaped and rarin’ to go come spring.