Soon it will be time to move any plants that may have been vacationing outdoors back inside. Their vigor has been renewed and tissues strengthened. You may even have a new plant this year that you think would make a great houseplant or one you can’t seem to part with. As much a your plant relishes fresh air the temperature may drop to an uncomfortable and even deadly degree about this time of year and you must re-acclimatize any plant you want to overwinter in your home. Try to give yourself time, a week or two, before it gets too cold, as most plants are somewhat stressed with changes in environment. Often you will notice the effects of this change, like some leaf-drop, regardless of how careful you may be.
Step one is to give your leafy plant a good gentle shower with the hose or watering can to knock off any critters and dust. Rinse the undersides of the leaves too. When dry, inspect thoroughly for any pests. Look closely at the tops and undersides of the leaves, the petioles, the stems and the soil. Do this every few days during the acclimation period. To search the soil you can use a spade to disturb the first few inches while watching for any movement. If you see problems in the soil, you can re-pot your plant into fresh, clean, pest free soil, or when it is time to water your plant you can get a container larger than the pot, place your plant, pot and all, in the container and fill it with water. Leave it there for an hour or so and any earwigs or others will leave or drown. You could also put a systemic pest control into the soil which will kill any insect hiding there in a few weeks.
At this time you will be moving your plant into a protected area, perhaps on your front porch with a roof overhead, a protected corner of the garden, or under a tree that is near the house for some protection from the elements. This is the same process you would use to harden-off a plant grown indoors that you put outdoors for the first time in the spring only in reverse. If the nights are really cold but the days are warm and beautiful you can put the plant indoors for the night and take it back out for the daylight hours. You may have a location outside with similar light to its place inside. Inside spaces often need some rearrangement now so you have a ready home for your plant to come into. Remember that winter light is not as strong as summer light and light is perhaps the most important thing you’ll need to give your plant. If your plant is really bushy you can thin it out so more light can filter through. This will help it receive more air circulation too which will cut down on indoor pest problems like red spider mites. Keep the windows open to help acclimate your plant indoors. They’ll love it if the temperature is right.
Less light – less action – less water. Late fall through early spring is a dormancy period for a plant and you will cut back on the watering. The more cool the temperature in your home the less you need to water. A warm room will dry the soil more quickly. You will not let the soil shrink totally from the sides of the pot but you may not water your Clivia, for instance, for several weeks. Your plants will not need any feeding from late fall through until early spring. If your home is forced air and dry you can add humidity.
I do this every summer for my Clivia and this year I will conduct an experiment with a white angel-wing begonia. I grow them each summer on my front porch and have to let them go when the weather turns cold. I have only a north facing window available for it but it is used to the north side of my house so perhaps it will be content to overwinter in my living room. It’s worth a try.
Some plants may be deciduous, a Caladium for instance, and lose their leaves as part of the life cycle. You can enjoy them for a few weeks indoors, put them away for the remainder of the winter, and bring them out again very early spring (about 6 weeks before your last frost date) to get them started on the new season. Caladium, Dahlias, and Glads are some of the plants you can remove from the soil, remove the recommended amount of greenery, store bare root at 45-50°F (7-10°C), (perhaps in a cardboard box of wood shavings) re-pot in the late winter, and enjoy the waking new growth for the following season outdoors.
Be sure to watch the nighttime temperatures carefully and bring your favorites indoors before it’s too cold. The gradual change from out in the yard to closer to the house or indoors at night will help in the adjustment and your diligence checking for pests will help ensure the transition is a healthy one.