Question: My indoor plants seem to be languishing in the dark winter weather. The leaves are dull and a lot of leaves are dropping off. Is there anything I can do to perk them up?
Answer: Light is a key ingredient for plant growth. We are in the lowest light conditions of the year. It is like a recession for plants. They almost stop growing or actually lose more leaves than they replace. As long as they are producing new leaves, there is not a lot to worry about. There are a few things which can help.
Make sure plants get the best light available. Plants which are away from windows can be moved closer. South facing windows get the most light. Make sure curtains and shades are open during daylight hours. Table and reading lamps make good supplemental light. Lights can be left on even when there is no one in the room, even overnight.
A new generation of indoor plant lights is available which give stronger light for less energy cost. LED plant lights can produce sufficient light even for higher light requiring plants. Fixtures are available starting at $25. Search online under “indoor plant lights” for more information. These same fixtures can also be used to start flower and vegetable plants from seeds.
Plants accumulate dust on their leaves which filters out light. Shiny leaf plants can be washed with water or leaf shine. Fuzzy leaf plants do not like water on their leaves, so a feather duster or similar tool should be used.
Avoid overwatering and overfertilization. Our tendency is to water plants on a regular schedule, such as once a week. Slower plant growth means less water and fertilizer are used by the roots. When soil stays too wet, oxygen is more limited for the roots which limits root growth. This in turn limits top growth. Check to make sure the soil is dry on top before watering. Reduce fertilizer by half to match the slower growth rate.
Replace high light requiring plants with those needing less light. Buy or check out an indoor plant book which gives light requirements or search online; “low light house plants." Indoor plants which tolerate the lowest light conditions include: Cast iron plant (Aspidistra), Peace lily (Spathiphyllum), Chinese evergreen (Aglaonema) and Snake plant (Sanseveria). Also very low light tolerant are: Dracaena, Dieffenbachia, Parlor palm (Chamaedorea elegans) and Devil’s Ivy (Pothos).