Ever notice how tropical foliage is split by a “vein” or a line down the middle….we call it a foliage “midrib”. In the tropics on hot days it helps the foliage fold on itself to conserve moisture. In fall and winter in our homes due to less light (in Michigan) the leaves flatten to maximize exposure to light. In many cases the center rib or line becomes less pronounced, a good indication your houseplant needs/wants more light. As the days get shorter give your plants a quarter turn weekly to maximize light exposure. Add some supplemental light. Keep foliage clean and dust free to maximize light exposure. A bright light window helps, direct sunlight is not necessary. The “midrib” will give you a good indication how your houseplants feel about the available light! Watch this video for more: