I have an indoor Gardenia plant. How do I know when to repot it? Also I’ve noticed some white stuff where the leaf is attached to the stem. Some of the leaves are turning yellow then brown and are falling off. How do I save this plant?
Gardenias rarely need repotting. Repot only when the soil dries out within 3 days following a thorough watering.
It looks like your Gardenia does need to be pruned. Simply cut off approximately the last third of each stem. This pruning will also remove many of the white mealybugs that are on your plant.
To treat the remaining mealybugs, mix a solution of 5 parts water, 1 part isopropyl alcohol and a squirt of liquid soap. Then, thoroughly spray all leaf and stem surfaces until they are dripping wet. This is a messy process but it is essential to get complete coverage of the entire plant to be effective.
Make sure your Gardenia is very close to a moderately sunny window. Water it as soon as the surface of the soil is almost dry. Try to keep temps as cool as possible.
It is common for older leaves to discolor and fall off. Remove then as they start to turn yellow.