I killed a beautiful potted geranium one fall by doing the obvious thing: leaving it outside until the night before the frost, then dragging it straight into my warm living room. Within a week the leaves dropped off like it was giving up on life.

The shock was the problem. Plants that have spent months outside need a gradual transition, not a one way ticket to the living room.

Move them before the frost, not the night of

The biggest mistake is waiting until the last minute. Start moving plants inside two to three weeks before the first frost date. This gives them time to adjust while the outdoor temperature is still close to indoor conditions.

Check your area’s average first frost date and work backward. For me that means mid September, not October.

The gradual transition method

Do not go from full sun outside to dim living room in one day. The transition plan:

1. Week one: move the plant to a shaded spot outside, like under a porch or tree.
2. Week two: bring it in for a few hours a day, out again at night.
3. Week three: bring it in for the night, out during the day.
4. Final move: bring it in for good.

Each step gets shorter and the plant adapts. I skipped this the first time and learned the hard way.

Check for pests before they move in

Before any plant comes inside, inspect it for bugs. Outdoor plants bring in aphids, spider mites, and ants, and they will spread to your indoor plants. Check the undersides of leaves and the soil surface.

I spray mine with a gentle insecticidal soap a week before moving them in, then check again the day of the move. It takes ten minutes and saves a lot of indoor pest drama.

Trim them back first

Plants that have spent the summer outside are often leggy. Prune them back by a third before bringing them in. Fewer leaves means less water demand and an easier adjustment. The plant will regrow compact and bushy over winter.

Adjust your watering

Indoor plants dry out much slower than outdoor ones. Cut watering way back after the move. Check the soil before watering, and only water when the top inch is dry. Overwatering is the number one killer of overwintered plants.

Give them the best window

The brightest window in the house is not enough after full summer sun. South facing is best, and a grow light helps if your windows are weak. Leaves dropping or stretching pale means not enough light. Rotate the pots weekly so they grow straight.

My geraniums came inside last fall with the gradual method and they bloomed through January. The one I killed years ago taught me the lesson, and my plants have been grateful ever since.