Fall is an excellent time to repot many houseplants. Potted plants that have been growing outdoors during the summer have probably grown quite vigorously due to the high light levels and greater humidity. If the top growth of the plant has increased in size by 20 percent or more, it probably should be transplanted into a larger container so the roots can stretch and settle comfortably.
Before You Repot
Before repotting, check the plant and the soil carefully for insects. Add systemic granules to the soil and spray the leaves with an insecticidal soap to remove any unwanted pests. If an insect infestation is particularly bad, it may be necessary to remove most of the plant’s soil and replace it with fresh potting soil. Avoid using soil from the garden, however, which will harbor insect larvae and eggs as well as weed seeds and other material you do not want in your houseplants.
Bring your plants indoors well before any danger of frost for proper acclimation to the indoor environment. The change in light levels and humidity could shock more delicate plants, and they may wilt temporarily or drop leaves before they adjust to the new conditions. If possible, bring them in just a few minutes at a time for several days, gradually increasing their indoor time to several hours before keeping them indoors all the time. Flowering tropicals will also benefit from cutting back some of their foliage to avoid shock before being brought indoors.
To help houseplants overcome the transition from outdoors to indoors, position them in a bright, sunny area and consider adjusting indoor temperature and humidity controls to more closely mimic outdoor conditions. Make adjustments slowly and gradually, and the plants will adjust.
Time to Repot
Once your houseplants are adjusted to their indoor fall and winter environment, they can be safely repotted without adding to their stress. Repot the plants early in the day, and move them to a slightly larger pot. Avoid jumping several pot sizes, which could lead to excessive root growth while the foliage is neglected. Be sure to fertilize and water the plants appropriately to provide them proper nourishment as they settle into new pots. Do not expect luxuriant foliage growth right away, however, as it will take some time for the plants to begin growing again, especially in fall and winter when most houseplants are entering a dormant, slow growth period.
By repotting your houseplants in fall, you can help healthy, vigorously growing plants adjust to a new environment and continue their growth with ease in a new, larger, more comfortable pot.