Most melastomes grown as ornamentals come from frost-free tropical or subtropical climates, which means winter — for anyone outside those zones — is the season that actually determines whether a plant survives the year.
Know your plant's tolerance
Tibouchina, the genus most commonly grown outdoors in borderline climates, generally tolerates a light, brief frost but not a hard freeze or sustained cold. If your winters regularly dip below freezing for extended periods, container growing with a move indoors or into a sheltered space is the safer approach rather than relying on in-ground survival.
Bringing plants indoors
Move container plants in before the first frost rather than after — a stressed, already cold-damaged plant adjusts to the move indoors far worse than a healthy one. Expect some leaf drop as the plant adjusts to lower indoor light; it's usually not a sign of a bigger problem.
Adjusting care for the dormant season
- Reduce watering frequency — growth slows significantly in lower light and cooler temperatures, and the soil stays wet longer as a result.
- Stop fertilizing entirely until active growth resumes in spring.
- Keep the plant away from cold drafts near doors or single-pane windows, which can stress it even indoors.
Bringing plants back outside
Wait until nighttime temperatures are reliably above the plant's frost tolerance before moving it back out, and reintroduce it to direct sun gradually over a week or two rather than all at once — indoor-grown foliage sunburns easily if it's moved straight into full outdoor sun.