Well, the time has come where we see less daylight, the temperature outside is dropping, and we’re all slowing down and cozying up in preparation for winter – and our indoor plants are doing the same!
During the shorter day periods between October and March, indoor plant growth slows, conditions in the environment can change, and some adjustments to the care we provide can be helpful to support our plants through the winter months.
Whether your plant is in a chilly windowsill, or next to a hot heat register, it is wise to monitor your plant for temperature stress. If a plant is getting too cold, you may notice its green leaves are wilting, turning black, or looking mottled. If a plant is too close to a heat source, you may notice the leaf edges become crispy and curled, or the plant appears to be wilted and thirsty more frequently.
If you notice any signs of temperature stress, try to find a new location for your plant that still has adequate lighting, but that is consistently a more optimal temperature for tropical plants (18-22 degrees Celsius). If the need to move your plant comes at the expense of lighting, you may need to consider light supplementation.
With dimmer and shorter days, plants will often drop some of their older leaves. This is a stress response and is the plant’s attempt to prioritize the energy it can photosynthesize, to nourish its newer growth.
In a well-lit space, a bit of mature leaf dropping at this time of the year isn’t anything to panic about, but if you already struggle to find good lighting for your plants, or if you have any high-light plants (Ex: cacti and succulents, dieffenbachia, crotons), you may want to consider supplementing your lighting to avoid major deterioration in your plant health.
There are many broad-spectrum UV lights on the market, with several options available in our city’s local gardening centers. Once you find the style that best suits your needs, you can provide your plants with eight hours of supplemental lighting each day, being sure to leave adequate distance between your plants and the lights to prevent burning the foliage (it is best to reference the user manual for instructions specific to the lighting system you purchase).
As growth slows, plants take up a bit less water, so it is recommended to gradually taper back on the volume and frequency of watering.
As always, there is an exception - If you like to keep your home especially heated and cozy throughout the winter, your plants may continue to need more consistent and generous watering. It is best to get comfortable assessing moisture levels in the soil with your finger, and knowing which plants like to stay consistently moist, which like to have the first inch of soil dry in between watering, and which like to dry out thoroughly.
Fertilizing & Topsoiling
The use of fertilizer is not usually recommended between November and February, as there is a higher chance of burning the root system when the plant is not in the peak of its growing cycle. The exception to this, would be for a vigorous growing plant (like pothos or philodendron), which could benefit from a very mild fertilizer (kelp or fish-based for example) year-round.
A safe alternative to fertilizer during the winter, is a process called ‘topsoiling’. It involves removing the top layer of existing soil in your plant pot, and replacing it with fresh soil; insect frass can also be added to topsoil for an extra boost of nutrients. This is a gentle way to support your plant's health throughout the winter.
If you practice Integrated Pest Management at home, diatomaceous earth can be added to the same topsoil to help treat any soil-dwelling insects that may be present.