Seasonal Light Changes Affects Your Houseplants, Pay Attention

Photo by Irina Grotkjaer on Unsplash

If you live anywhere that isn't the equator, you've probably noticed the daylight changing in the last few weeks. It's not just that the days are getting shorter, the angle of the sun in our windows is changing. In the northern hemisphere, we're heading into the part of the year where the angle of the sun is low in the Southern sky for most of the day.

For Radar, this means nice warm sunbeams all around the house to have naps in. For your houseplants, it's a bit more confusing. The shorter days mean your houseplants are getting less light overall. So you might think it's time to move them closer to South or West windows, to maximize natural light.

Don't be so hasty. The angle of the sun also means that some of your plants will be getting more direct sun than they did in the summer. In my house, plants on the north wall of our living room are now starting to get direct sun for part of the day.

Most of our houseplants are from tropical and sub-tropical rainforests. Rainforests can be fairly dense and have a significant canopy. Many of the plants get dappled light, but not much direct sun. So moving your plants closer to the window for the winter may not make them happy. They may end up getting sunburned.

This is especially important in places with lots of winter sun, like most of Alberta. Between tons of direct sunshine and furnaces turning on to dry out the air, your plants can struggle. The day length is signalling many plants to go into a period of dormancy for the cool rainy season, but your furnace is keeping them at a nice moderate temperature with very dry air. It's confusing.

So how do you mitigate the effects of too much sun, too much dry air, and changing light?

Start noticing how the light is changing in your home. Notice which plants are getting direct sun now that weren't before, and others that aren't getting enough. Do a bit of research on your specific plants to learn what conditions they prefer during the winter.

If you like apps, you can use the Planta app. I've had it for a couple of months now, and I have mixed feelings about it. It did help me find better locations for a few of my plants that were getting too much sun or not enough. I did have to create multiple zones with different lighting conditions for every room, which kind of annoys me, but it works. I have noticed that the plants I've moved do seem to be happier in their new locations.

Planta also does suggest that you make seasonal adjustments to your plant care, but I haven't read what they suggest. You don't need an app to adjust your plant's seasonal locations though. You can figure it out yourself with a little research, or by paying attention to how your plants are doing at different times of the year.

One way that you can protect all your plants from the sun, but get them closer to the window for brighter light, is with sheer curtains. Sheers will cut enough light to prevent sunburn to plants near south windows, while still allowing a decent amount of bright light.

Radar, Worshiper of the Sun, does not appreciate curtains ruining her sun patches, so I move plants around as necessary.