Unfortunately, it is already starting to get cold here in the northern United States. (I’m not ready to be back in the house all winter.) The night time temperatures have been dropping into the mid to low 50’s and it is time to bring any tropical houseplants inside. Luckily, it is still in the low 70’s during the day, so it’s not an emergency. The type of plant, where you live, and the nighttime temperatures, will determine when you move your houseplants back inside. For us here in Michigan, it is now. Not only has it been cold, but rainy and a cold, wet plant is an unhappy plant.
Cacti and other succulents
The Thanksgiving cactus above and other cacti and succulents can take quite cold temperatures, as long as it isn’t freezing and their soil isn’t wet. Believe me, I have allowed some of them to freeze outside in past years. As a group of plants, cacti and succulents can probably take the lowest temperatures of all plants. It seems to help trigger some of them to bloom. Where they are from naturally, it can get very cold at night, so they are accustomed to it.
There are other houseplants that cannot tolerate low temperatures. They will drop leaves and may completely collapse in temps below 50. At the very least, they will pout.
Steps to take before bringing inside
- It is best to start acclimating your plants to a lower light situation by placing plants in the shade under a tree or on the north side of your home for a couple of weeks before bringing them inside. (This step should be done starting at the end of August.) If you, like me are caught unaware with temperatures already low at night before you start acclimating, this step may not get done.
- Wash down the outside of the pot including the saucer. I would wash the cloth off before using it on the next pot or use paper towels and toss them. You don’t want to move insects from pot to pot if there are any.
- Check the plant for insects, such as scale and mealybugs. Check in the leaf axils (where the leaf meets the stem), under the leaves, and on the stems. Check for discoloration, sticky substances, bumps, and anything unusual that doesn’t match the plant.
- Wash the foliage off and even use a hard stream of water if needed to get anything off the plant that shouldn’t be there.
- Flush the soil extensively to wash anything living such as roly-polys or worms, out the drainage holes. You could even use very warm, but not too hot, water to make anything residing in the soil uncomfortable so it will hopefully leave. It is a good idea when taking your houseplants in the spring, to use pot feet to raise the pots up off the ground or patio, to make it a bit harder for insects and worms to take up residence in the pot.
- I like to use a systemic insecticide such as Bonide Houseplant Insecticide in the potting medium to ensure that any living insects on the plant or in the soil will die before bringing it inside.
Steps to take inside the house
- When you first bring your plants inside, give them as much light as possible to help them acclimate. If you need to move them into a lower light situation later, do so. Even a week or two of higher light inside before moving to a lower light will help them acclimate.
- Wash your windows! You can’t imagine how much difference that will make to your plants. Clean the screens, as well, or remove them if you can.
- Make sure you wash your plants often to keep the leaves clean and free of dust. The dust and grime on your leaves block the light that they need for photosynthesis which makes their food.
- Keep your windows clean.
- Up the humidity with a whole-house or room humidifier, or if you only have a couple of plants, use a pebble tray under your plants, like the one pictured below.
- Clean your furnace filters often to keep the dust down in your house and off your plants.
Hopefully, this will help you bring your plants in from outside with as little stress to your plants as possible. Remember, your plants will probably lose a few leaves and may pout for a few weeks, but will probably recover and thrive as long as you acclimated it well in advance. Remember, they really don’t need fertilizer at this time of the year. I don’t fertilize again until early to mid-March depending on when it warms up.
Good luck and have a good week!