What you should know before you keep your houseplants on the windowsill this winter

Oct. 24—This story was originally published in October 2020.

It seems obvious that you'd want to keep your houseplants on the windowsill, especially in winter. But in reality, it's not that simple .

Window philosophies differ in the houseplant world. Lauren Tuell, founder and owner of Mainely Succulents in Orono, said that she finds her houseplants do better when they are closer to windows during the winter.

"As the days shorten the plants are going to receive less natural sunlight," Tuell said. "Making sure you're getting the most natural sunlight is ideal."

But there's nuance to positioning plants for the best result.

The position of the windows matters when it comes to sunlight exposure, so make sure you know which way your windows are oriented. Melissa Higgins, wholesale manager at Sprague's Nursery in Bangor, said that southern and western facing windows are best for maximizing sun exposure.

Tuell said that it is also important for houseplant owners to be mindful of window cleanliness if they want to maximize their effectiveness of giving houseplants more light.

"Sometimes just having dust build up on the windows filters the sun [and there is] less sun for photosynthesis to happen," Tuell said.

Still, keeping plants right next to windows could do more harm than good.

Many windows, especially in old houses that are prevalent throughout Maine, are prone to cold drafts in the winter, which can be fatal to plants.

"Be mindful of any harsh drafts that come in through the window," said Ellie Longfellow of Longfellow's Greenhouses in Manchester. "Sometimes plants can have leaf damage due to the cold that is coming in from the window and off of the glass. It is not always problematic, but something to be mindful of if there is a draft or extreme cold."

Instead, place the plants a few feet from the glass — far enough that they don't touch the window in case it freezes over, but close enough that the plants will still reap the benefits of the sunlight, according to Longfellow.

You can also take extra precautions to prevent drafts from coming through your windows. Higgins said that wrapping windows can help relieve cold drafts.

The window issue for houseplants goes behind a breezy chill, though. John Sundling, owner of the Plant Office in Portland, not only keeps his house plants further away from windows to avoid drafts, but also in order to better capture the light the way it falls in his particular living space.

"We [also] have changing light — bright direct light gets further into our houses in the winter because of the angle in the sky," Sundling said. "I have to move my houseplants away from the window for the more light-sensitive ones."

So, what is the answer? The best thing to do is to spend some time watching your indoor environment to see where the light falls and where the drafts come in. Then, tailor the placement of your plants to the environment they are living in, while taking other steps to ensure your houseplants survive the winter.

"Observing the change in how the sunlight works is a way to think about it," Sundling said.