Before the First Frost: Bringing Your Plants Indoors for Winter

The warm days of summer will soon give way to cool fall nights. If you keep any houseplants outdoors, it is time to start thinking about bringing them inside.

The majority of plants kept as houseplants come from tropical, subtropical, or arid regions and can easily be damaged when temperatures fall below 50°F; it would be unwise to wait until temperatures dip that low before you start bringing your plants inside. In addition, moving plants indoors earlier gives them time to adjust to the differences in light intensity, humidity, and watering that occur indoors.

Monitor the Forecast

Focus on the weather forecast, not necessarily the calendar. Monitor overnight temperatures, especially nighttime lows. Keep in mind that temperatures around 40 to 50°F can damage your plants; you want to start preparing to bring them inside before temperatures get this low. Cold-sensitive tropical plants may need to be moved inside even sooner, before temperatures fall anywhere near the danger zone. The bottom line is: Do not wait until the first frost to start moving plants indoors.

Inspection

Inspection is a crucial step in preventing unwanted guests from going into the house. Carefully inspect the leaves, stems, and soil for signs of insect activity or disease. Remove and dispose of any infested, damaged, or diseased leaves. If plants are severely infested or diseased, it is probably best to dispose of them to prevent them from affecting other houseplants.

A good rinsing from the garden hose can remove many pests from the leaves and stems. Soaking plant pots to the rim in lukewarm water for at least 15 minutes can help flush out insects hiding in the soil. If necessary, consider using an insecticidal soap or horticultural oil labeled for use on the specific plant and pest. Make sure to follow the label directions. Allow the plants to drain and dry completely before bringing them inside.

Quarantine

When bringing your plants inside, consider isolating them for three to four weeks before putting them anywhere near your already-established indoor plants. This isolation period will allow time for any pests or other problems that may not be readily apparent to appear and be addressed before they spread to other plants.

Transition

If possible, gradually reduce the light your plants receive about one to two weeks before bringing them indoors; this will give them time to adjust to the reduced light indoors rather than experiencing a dramatic change all at once. Once inside, place them according to their light requirements. Plants that need a lot of light will do well placed near a sunny, south- or west-facing window. In general, many common houseplants can be placed in bright, indirect light. Some yellowing or leaf drop may occur once the plants are indoors, but this is a normal response due to the change in light and growing conditions. Plants brought indoors can take 1 to 2 months to adjust to their new environment; new growth can occur once they adapt.

Care Routine

It is important to remember that houseplants often slow their growth indoors due to the changing environmental conditions. Because plants grow more slowly due to reduced indoor light, they will not need as much water; adjust your watering accordingly based on soil moisture rather than following the same outdoor watering schedule. In addition, consider the plants' humidity needs. Grouping them together, keeping them away from drafts and heat sources, and using a humidifier are some ways to increase the humidity level around plants. Fertilizer is generally unnecessary during this time, especially if the plants are not actively growing and producing new leaves, stems, or flowers. Continue monitoring the plants regularly throughout the winter for pests, as they can become more noticeable indoors.