Just as students head back to school when summer winds down, our houseplants need to come home, too. Plants that spent the warm months outdoors should be brought inside before nighttime temperatures fall below 50 degrees, especially tender flowering varieties that don’t take kindly to chilly nights.
When it comes to bringing potted plants indoors, timing is everything. The combination of indoor heating and lower light can be stressful, so don’t wait for the first chilly night. Bringing plants inside while conditions are still mild gives them a chance to adjust before winter settles in.
Here on the Southcoast, mid- to late October is generally a good time to bring most houseplants back indoors. But if you’re growing sensitive tropicals, such as fiddle-leaf figs, elephant ears or hibiscus, don’t wait that long. Bring them in when nighttime temperatures dip to 60 degrees — or, as I like to say, basically do it yesterday!
But don’t simply carry a plant in from bright summer sunshine and plunk it down in a dark, dry house. The sudden change in light and humidity can cause leaf drop and serious stress. And before you welcome your plants back inside, remember that outdoor pots and foliage can come with some unwelcome hitchhikers: aphids, spider mites, fungus gnats and even sneaky slugs.
Instead, follow these steps to give your plants a smoother transition indoors.
Evict the bugs. Start a week or two before the big move. Using a garden hose, thoroughly spray the tops and undersides of the leaves to dislodge pests. Wash the outside of the pot and check underneath the drainage holes for hidden slugs or other critters. Finally, treat the foliage with an insecticidal soap or neem oil, following the product directions carefully. To help prevent a fungus gnat invasion in your living room, consider treating the soil with an appropriate product labeled for fungus gnat larvae.
Give them an acclimation period. Move your pots to a deeply shaded outdoor area, such as a covered porch or beneath a thick tree canopy, for about a week. This allows plants to adjust to lower light levels before making the transition indoors. If you have the time, you can also bring them inside on chilly nights and return them to their shady outdoor spot during the day for several days.
Groom and prune. Cut back some of the leggy growth produced during the summer. This makes plants easier to manage indoors and reduces the amount of foliage the roots need to support. Remove yellowing or dead leaves, too, where moisture and mold can become a problem.
Choose the right indoor location — and quarantine. Keep newly arrived outdoor plants separate from established houseplants for several weeks to make sure any hidden pests don’t spread. Give them as much natural light as possible, ideally near a sunny south- or west-facing window. If your home is dark, an inexpensive LED grow light can help. Keep plants away from heating vents, radiators and drafty doors.
Dial back the care routine. As daylight hours shorten, most houseplants slow their growth, so their watering and feeding needs change, too. In general, stop fertilizing during the winter unless the particular plant calls for it, and water less frequently than you did outdoors. Don’t water by the calendar — check the soil first. If the top couple of inches are dry and the plant’s needs call for watering, give it a thorough drink and allow excess water to drain away.
When in doubt, throw it out. If a plant is looking particularly shabby now, bringing it indoors probably won’t improve its appearance. In fact, it may look even worse by Christmas — and worse still by New Year’s. Sometimes the kindest thing to do is let it go and replace it with a fresh, healthy plant.
It also isn’t the ideal time to repot. Unless a plant is truly root-bound or has another urgent need, save repotting for spring, when plants are gearing up for a new season of growth.
And if a plant looks a little under the weather, resist the urge to shower it with fertilizer. First, make sure it has the right light, water and temperature. Once it’s settled indoors and actively growing, a mild dose of liquid fertilizer may give it the boost it needs.
“The trees are in their autumn beauty,
The woodland paths are dry,
Under the October twilight the water
Mirrors a still sky…” — William Butler Yeats
The Seaside Gardener
By Laura McLean