1. Keep an Eye on Temperature
While your own summer vacation may have had a fixed end date, it’s a little trickier to figure out when that might be for your vacationing houseplants. It depends on the temperature, and specifically the nighttime low temperatures. You’ll want to move your houseplants indoors before night temperatures get below 45°F. Any colder, and you’re likely to see damage, especially on tender new leaves and stem tips.
2. Get Rid of Pests
While the great outdoors provides plants with plenty of humidity and warmth over the summer, it can also expose them to more pests. Some common ones to look for include aphids, scale, and spider mites. Before moving your houseplants indoors, first check them carefully for pest problems. Make sure to turn over leaves to check the undersides and look closely along the stems. Spray any pests you see with insecticidal soap ($10, The Home Depot). Even if you don’t spot any bugs, just in case, wash your plants with a strong spray of water from the hose.
3. Give Houseplants Time to Acclimate
Once pests are under control, slowly acclimate your plants to lower light levels by putting them in a shaded spot for a couple of weeks before moving them inside. After that, check them once more for any pests, and if needed, treat again. If your plants have gotten a little overgrown, now’s also the time to trim them back a little and remove any dead leaves so you can keep the mess outside.
4. Cut Back on Water and Fertilizer
Once your plants are back inside, think of winter as their rest period after a busy summer of growing, and, in some cases, flowering. While they won’t go completely dormant, many tropical houseplants naturally slow their growth during the colder months. This means they don’t need as much water or fertilizer as they did during the warm growing season. Instead, hold the nutrients until spring and keep your plants watered just enough so they don’t dry out completely.
5. Provide Light and Humidity
Even though your houseplants are resting, they still need bright, indirect light. Because days get very short in winter, you might want to consider supplementing with grow lights. And while your plants don’t need as much watering, they do appreciate a little extra humidity, given that most heated homes have very dry air. Use a humidifier or mist your plants daily, especially if you notice leaf tips turning brown and crispy.
How to Overwinter Tender Garden Plants
Many perennials, shrubs, and vines in your garden or outdoor containers can actually be kept alive in your home over the colder months, then brought back outside in spring. Although most of these plants prefer a cool location in the range of 60°F to 69°F during the day, and 10 degrees lower at night, they will tolerate warmer indoor conditions. When you bring them inside, cut them back slightly; this helps control size and encourages new growth that will be better adapted to life indoors. (Repeat the process in spring when you take the plants back outside, to help them acclimate to being outdoors again.) Otherwise, the same tips for bringing in your houseplants apply to the following types of popular plants that you can overwinter indoors.
Angel’s trumpet (Brugmansia selections) Begonia (Begonia selections) Citrus (including lemons, calmondins, and kumquats) Coleus (Solenostemon selections) Geranium (Pelargonium selections) Hibiscus (Hibiscus rosa-sinensis varieties) Impatiens (Impatiens selections) Mandevilla (Mandevilla selections) Passionflower (Passiflora selections) Pentas (Pentas lanceolata) Rosemary (Rosmarinus officinalis)