How to overwinter geraniums indoors.

1. Move a healthy plant before frost.

This plan is for a zonal geranium (Pelargonium), the familiar patio flower. Hardy cranesbills belong to a different group and do not need this indoor routine. Check the plant label if you are unsure.

1. Watch your local forecast. Bring the pot inside before its first autumn frost. A warm afternoon does not cancel a cold overnight low.
2. Inspect before moving. Look beneath leaves and along stems for insects, damaged tissue, or rot. Do not place a troubled plant among healthy houseplants; resolve the problem first.
3. Tidy the pot. Remove fallen leaves and spent flower stalks. Keep an already-potted plant in a sound pot with open drainage holes; it does not automatically need a larger container.

2. Choose light before choosing a shelf.

Use a bright, sunny window or suitable grow light. A dim hallway may fit the pot but cannot support the same growth. Cool indoor conditions suit geraniums; Iowa State suggests roughly 65–70°F (18–21°C) by day, with slightly cooler nights.

3. Check the mix; skip the summer schedule.

Feel the soil surface before watering. When it has dried, water the mix and let excess drain away. Empty the saucer or decorative outer pot. Check regularly, but do not add water simply because your usual watering day has arrived.

Pause the outdoor fertilizer recipe when growth slows. More fertilizer will not replace missing light. If stems become long and weak, reassess the light and room warmth before adding feed.

Persistent wilting while the mix stays wet calls for a drainage and root check, not another drink. Watch the condition of the whole plant rather than treating one aging leaf as an emergency.

4. Restart gradually in spring.

As spring light improves, remove dead material and trim leggy growth back to healthy stems. Keep the plant in good light while fresh growth develops. Use new growth and soil condition to guide care; do not promise a fixed flowering date.

Return outdoors only after local frost danger has passed. Begin in a sheltered spot and increase outdoor exposure over about a week, rather than moving directly from a windowsill into full patio sun. Resume the zonal geranium growing plan for active outdoor growth.

Next check: review your indoor light now, or use the first-frost checklist for the other pots still outside.