Many people move their houseplants outdoors in the summer to give them extra light, heat and air circulation. This is a great practice but you need to begin thinking about the process of moving them back indoors in the next month or so, as night temperatures begin to drop. Most tropical plants will suffer damage at temperatures below 40 degrees F, a few at 50 degrees F.
Because conditions differ widely between inside and outside your home, a gradual reintroduction to the indoors is best. This change is called acclimatization. Sudden changes in temperature, light, and humidity can be traumatic to plants, resulting in yellowed leaves, dieback, wilting, and even death.
Bring your plants in gradually to accustom them to the much lower light levels found in most homes. Setting them under a porch, carport or shady place during the day to reduce time in the sun will help before bringing them in for good as temperatures drop. It’s best if they’ve been outside in high light to put them in similar light indoors like a south window or under plant lights on a timer for up to 16 hours a day.
Once inside, ensure that your plants will be in a location where there is adequate light, preferably natural light from windows. You also might need to add ceiling hooks for hanging plants or build a wide shelf in front of the window to get the plants closer to a good light source. You may have to install a “grow light” for plants that need additional light or if you have a location where there is not enough light to keep your plants healthy.
If you have plants that require high humidity, you might want to make the shelf wide enough to accommodate trays to group these plants together. Line the trays with waterproof material, fill with gravel, and place the pots on top. Keep the gravel moist.
Often the relative humidity is too low in our homes, and this causes plants to lose water faster through the tiny openings in their leaves than they can replace it through their roots. During winter, when indoor temperatures are raised, the air is dry, which can have an adverse effect on plant health.
Inspect plants for insects and diseases before bringing them inside. It can be difficult to remove diseases and insects safely once they are inside.
DEALING WITH INSECTS
If you discover insect infestations, there are several courses you can take. What you can do will depend on the kind of insect or disease involved, the degree of infestation, the kind of plant involved and its value to you.
Options include disposing of the plant; pruning out the infected part; handpicking off visible insects or diseased plant parts; using an alcohol swab to wipe off insects; pressure spraying or washing the plant; or as a last resort, using an insecticide spray specifically labeled for interior houseplant use.
Check the outside of the pot for dirt, cobwebs, or unwanted inhabitants. Spraying down the pot will remove debris from the summer. Soaking the pot in a tub of lukewarm water for about 15 minutes will force insects out of the soil. Be sure to let the pot sit to dry and drain well before bringing it inside. Wiping off the outside of the pot with a wet cloth (be sure to wipe off the bottom too!) will help remove critters that might be hiding in cracks and crevices and emerge later on.
If necessary, repot plants. This is best done now before bringing the plant indoors or if you can wait, in the spring when the plant goes back outside. If plants have gotten leggy during their outdoor stay, remove from the container, and prune the top and roots in equal proportions, then repot, using fresh, sterile, high quality, soilless potting mix.
DON'T OVER WATER
Don’t over water once your plants are inside!
Although you may have had to water your container plants every day when they were outside, indoors they won’t require anywhere near as much water. Let the soil surface get dry to the touch before watering again. Water succulents less often, when the soil is dry for several days.
Don’t water if quite cloudy outside, rainy weather, or at night as plants won’t get sufficient light indoors to dry out. It is best to water indoor plants when they need it and not on a set schedule. Using room temperature water is also often less shocking to indoor plants.
Finally, give your plants a small boost of water-soluble fertilizer when they first come indoors. You can use a slow or timed release pelletized indoor plant food.
Plants that have been repotted with soil containing fertilizer will not need to be fed again for two to three months. Even under the best of indoor conditions, plants will likely need less water and fertilizer than they received outdoors.
For more information on houseplants, log on to: http://www.uky.edu/Ag/Horticulture/homehouseplants.html. You may also contact the Franklin County Cooperative Extension Service at 695-9035 or email DL_CES_Franklin@email.UKy.edu.