To us, it seems like the environment in our home stays pretty consistent all year round. The temperature is usually pretty constant, and we don’t really notice changes in other indoor climate factors like humidity and changes in light. We notice that the days get shorter, but otherwise, it feels like our house stays the same.
But it doesn’t. Our houseplants are much more sensitive than we are. They notice the temperature changes more. If you’ve got air conditioning, they notice the chill in summer. If you don’t have air conditioning, they notice the heat that creeps in from outdoors. They notice the changes in humidity levels from season to season. And in winter, they notice, most of all, the difference in light.
Some of us might notice some of these changes in our skin, like humidity; when the furnace starts to come on, you might find you need more lotion and extra lip balm.
What all this means is that the needs of our houseplants change through the seasons. In particular, changes in humidity levels, light changes, and slowed growth can affect your houseplants’ overall health and happiness.
Seasonal Light Changes
The tilt of the earth’s axis means that our plants’ light exposure changes over the year. In the winter, the sun is much further south, shining directly into south-facing windows for a good chunk of the day, but only getting into east and west-facing windows for a few hours in the morning and evening.
In the summer, the sun comes up quite a bit further north, going directly overhead, and then setting quite far in the north-west. South-facing windows may only get a few hours of sunshine, and the sun won’t reach as far into the room as it does in winter. Because the days are longer, the east and west windows may get several hours of direct sun each day.
That means in winter, plants in rooms with west, north, or east-facing windows are getting a lot less light than they did in the summer. And plants in rooms with south windows are getting a lot more light.
In summer, it’s the opposite; south-facing rooms get less sun than usual, and east and west windows (and sometimes even north windows) get a lot more light than in winter.
Move Your Houseplants to Adapt to Light Changes
Start noticing how far into a south-facing room the light hits at midday. If you had an African Violet, Philodendron, Pothos, or a ZZ Plant pretty close to a south window in the summer, you should start moving them back from the window a bit, so the leaves don’t get sunburned.
If you have low-light houseplants near the wall opposite of a window in a west, north, or east-facing room, they’ll be happier if you start to shift them closer to the window, so they’re a little closer to what daylight they’ll need through winter.
Any plants that require very bright light should be moved to rooms with south-facing windows, or you may need to invest in plant lights to compensate for the short days during the winter.
Ideally, most plants should have about 12 hours of light per day. You can get plant lights with built-in timers or add a Christmas light timer to them. Timers make it much easier, so you don’t have to think about the task of keeping track. Just set it and forget it!
Give Your Houseplants Some Humidity
Summer is the most humid part of the year in Des Moines, and plants love it. Humidity levels here are pretty moderate throughout the year. Sometimes we hit 80% in December, the most humid month of the year, but usually we hover closer to 70%. But, that’s outdoor humidity.
Furnaces tend to dry out the air inside our homes. So the humidity level inside your house is likely to be a fair bit lower in the winter. If you find your plants’ leaves are getting crispy edges or flower buds dry and fall off before opening–they need more humidity. You can improve humidity for your plants in a few ways.
- Grouping your plants closer together will create a bit of a canopy, like a rainforest. This will help keep the air around your plants a little more humid.
- Close heating vents near your plants, so warm dry air isn’t flooding their living space every time the furnace comes on.
- Add pebble trays or run a humidifier near your plants. Pebble trays can be placed under every plant. Just fill a shallow dish with small decorative gravel, set your plant pot on top of the gravel with its drip tray underneath it, and then fill the pebble tray with water. Refill the pebble tray as it evaporates. Keep in mind not to submerge the bottom of the pot with water as you don’t want it to drown.
Adjust Your Watering Schedule
As the seasons shift, you should adjust your houseplant watering schedule accordingly. Essentially, you shouldn’t stick to a set schedule for watering. During the winter, most houseplants grow slower, so they use less water. But, that doesn’t just mean cutting back your watering. The other consideration is that furnaces make the air dryer in our homes, so water in the soil will evaporate faster.
The best rule of thumb for watering is to check the soil with your finger at least once per week. If the soil is dry to a depth of about 1-1.5 inches, it’s probably a good time to water. If the soil is still damp, wait a couple more days.
Keep in mind that small pots with hardly any soil will dry out faster than other pots, so you may need to water them more frequently than any of your other houseplants.
You should keep an eye on light changes, and adapt your watering level all year long. For humidity, you can leave pebble trays under your plants year round; it won’t hurt them. With flexible and seasonally adapted care, your houseplants will be happy all year round for a long time!