The 50-50 Rule for Bringing Plants Inside for Winter
For many plant parents, the name “houseplant” is literal. They let their beloved plants live indoors all the time and personally give them the light, humidity, and watering they require. But some plant parents who live in warm climates might move their houseplants outside for summer, giving them a vacation to a porch, patio, or balcony for more sunlight and a watering schedule that’s a little more in tune with Mother Nature.
Of course, in most instances, those plants can’t stay outside year-round. Houseplants are most commonly native to tropical regions and often can’t survive a frost, let alone months of sub-freezing temperatures. So when do you need to bring houseplants back inside for the winter? And how can you be sure they’ll receive the special care they deserve as they acclimate to their temporary winter home?
Here, plant experts weigh in on which plants need to come indoors and when, along with the best practices for doing so. Read on to learn more about when to bring your houseplants inside and how.
When to Bring Plants Inside for Winter
Follow the 50-50 rule: Bring houseplants inside 50 days before the first frost, or when temperatures are consistently around 50 degrees Fahrenheit.
Which plants need to come inside for winter?
Tropical varieties should all come inside before weather cools, says Rituparna Simlai, founder of Studio Arth. Because they hail from tropical areas, these plants thrive in the temperature range of 70 to 80°F. Tropical houseplants that need to come inside for winter include the following:
- Citrus plants
- Fiddle leaf fig
Tropical plants, unlike plants native to colder regions, aren’t wired to go dormant in cold weather and re-emerge when temperatures warm up again. If tropical houseplants are left outside for the winter, they’re done — you won’t see those plants come back again.
Tender herbs like basil will need to come inside, too, says Lindsay Chastain, a homesteader and founder of The Waddle and Cluck blog.
Some potted plants can stay outside, though. Simlai says houseplants that can go dormant outside for the winter are typically the hardier ones (although you’ll need to check instructions for your specific plant to make sure they can survive winter in your region).
Some examples of plants you might be able to leave outside for winter include jade plants, boxwood, and sedum.
Hardy perennial herbs like lavender and rosemary can also stay outside and go dormant, says Reesav Niraula at Plants Craze, but she recommends ensuring they are well-mulched (use a 3- to 4-inch layer) and protected from frost.
When should you bring plants inside for the winter?
Plant roots are delicate and susceptible to temperature changes, especially if they are planted in a container or pot as opposed to being in the ground, Simlai says. That means you’ll need to pay close attention to temperatures to determine when to bring your plants inside.
“A good rule of thumb for bringing the plants inside is the 50-50 rule, which means you should get plants inside 50 days before the frost arrives or when the temperature consistently reaches the mid to high 50 degrees Fahrenheit,” she explains. “Another indicator is when you begin to notice significant temperature fluctuations between day and night during the fall season.”
Before bringing them in, Gene Caballero, co-founder at GreenPal, recommends inspecting plants for pests or diseases and treating them as needed. If you skip this step, you put your other houseplants at risk. “It’s also a good idea to give them a good watering before moving them,” he says.
How should you acclimate plants when you bring them inside?
It’s extremely important to acclimate plants gradually to the indoor environment, as sudden change in light and humidity can stress plants, Simlai says. Start this process in the fall, as the longer they stay outdoors, the more time they’ll need to recover indoors.
Simlai has a few pro tips for helping houseplants make the transition from outdoors to indoors.
Before moving them inside, slowly increase the amount of shade plants get.
Place outdoor potted plants in shaded areas with limited light for a couple of weeks before bringing them inside. This helps them adjust to lower light levels.
Keep pruning to a minimum.
Consider trimming large leaves and stems if necessary while plants are still outside. But once you bring plants indoors for the winter, avoid any significant pruning, as it can stress them out.
Avoid repotting (for now).
Refrain from repotting your plants, especially into larger pots, right before moving them inside. Well-established roots will help the plant adapt more easily. You can re-pot plants next summer.
Clean your plants.
Give your plants a good shower to clean their leaves and remove dust. Consider spraying them with your favorite pesticide, preferably an organic, plant-based option like neem oil.
Once indoors, give plants plenty of light.
Place your indoor plants near a window with adequate light. South-facing or southeast-facing windows typically receive more light. If natural light is limited, you can set up grow lights. Note, though, that not all plant species thrive in bright light conditions — certain ferns and philodendron species are more suited to survive in low light levels.
Limit houseplants’ exposure to drafts.
Avoid placing your plants near vents or areas with excessive airflow, as this can reduce humidity levels and cause the leaves to dry out.
As for watering indoors, you may find that your plants don’t need to be watered as frequently as before, says Ara Flink of Propagation Diaries. If plants are continuing to grow new leaves, you should still maintain a regular watering schedule — but make sure to check that the soil is dry before adding any more water.
Be careful of placing your plants close to space heaters, Flink adds. This may cause plants to dry out much faster and even burn.
When can you take plants back outside?
Once nighttime temperatures reach and stay above 60 degrees Fahrenheit and the risk of frost has passed, it is safe to begin moving your plants back outside.
“Just as you gradually acclimated your plants to indoor conditions when you brought them inside for the winter, you should also ease them into the outdoor environment,” says Ward Dilmore, founder and head landscaper at Petrus Landscaping. “Start by placing them in a sheltered, shaded spot for a few hours a day and gradually increase their exposure to direct sunlight and outdoor conditions.”