This time of year houseplants may start to look a bit tired and even drop leaves. This often causes concern for the plant owner but it is a fairly natural response to lower light levels that the plants are experiencing. The lower light levels are a combination of shorter days and the lower angle of the sun in the sky. As a result of the lower light levels, the plants receive less energy for their metabolic processes and can become stressed. Typical plant response to stress is a slowing of growth and also the possibility of leaf dropping. You can move the plant to a brighter location, not in direct sunlight, near a window, add supplemental artificial light, or just wait until the days are longer and there is naturally more light. The plants will readily attain their healthy, thriving appearance again. You should not assume that the plant needs more fertilizer or additional water. The addition of water and fertilizer can harm a stressed plant rather than help. Hold off on fertilizing until new growth is ready to start in the spring. Watering should only be done to maintain the plant as it is basically marking the time until the new growing season arrives. You should check your plants regularly and only water them when the soil is dry, ½ inch deep in the pot. Although plants are sometimes forgotten and then totally dried out and die, the more common occurrence is that they are overwatered and expire from too much water.