This is an ideal time to get houseplants ready for a season ahead indoors.
First, check to see whether your plants need to be repotted. Water the plant well so the soil will stick together. Knock the plant gently out of the pot and inspect the root system. If you have a really tight root ball, you might need to get a slightly larger container.
If you need to repot a plant, select a good lightweight sterile soil mix, available at any garden center or nursery. I prefer light mixes that have good water-holding capacity yet are sure to drain. The No. 1 cause of death of houseplants is overwatering, and many of the bargain potting soils can become heavy and hold too much water. Lighter soils might be a little more expensive, but they provide superior aeration, and water-holding and nutrient-holding capacity.
If you don't want to go to a larger container, no problem. Lift the plant and prune the roots by one-third, then prune one-third of the plant to match the root loss. I kept an Improved Meyer lemon for about 15 years by repeating this process.
If the plants have been outside, inspect them closely to be sure they aren't harboring insect pests.
Remove any diseased or dead foliage, and pinch back growth to make a tidy appearance. If your plants have been outside on the porch or patio, they probably have received a tremendous amount of light compared to your indoor environment. The thousands of footcandles of light they received outdoors will be reduced to a few hundred indoors. So bring plants indoors gradually.
Move them from their outside location to a shadier spot for a few days to acclimate them to less light. Your watering regimen will be just as crucial. We often are so used to pouring on the water daily when they were outside that we forget to check the moisture level after we've brought them indoors.
Because the plants aren't growing as vigorously, if at all, they don't need nearly as much water. Check the soil to verify that it is dry before watering. You never want the indoor plant to be in soggy soil. When you do water, give the plant enough that water drains through the soil and out the hole. Then let the soil dry before you water again. There is no set calendar for indoor watering; it's when the plant needs it.
Because the plant is not actively growing and we cut back on water, it stands to reason we shouldn't fertilize nearly as often. Use a dilute fertilizer mixed with the water about every fifth watering. Nothing will make you enjoy your home more than healthy tropical plants indoors, so get them ready now for winter.