Ever woken up to a frost warning you did not see coming? The weather app said 50 and clear, and by morning the garden was covered in white. Potted plants take the hit hardest because their roots sit above ground, exposed on all sides.

I lost a whole rosemary bush that way. It looked fine at dinner and was mush by breakfast.

Why pots are in more danger

In the ground, soil insulates roots. In a pot, roots are surrounded by cold air. A potted plant can freeze while the same plant in the ground shrugs off the night.

Quick protection when frost is coming

1. Move pots against the house or under an overhang. The wall radiates heat.
2. Group pots together so they share warmth.
3. Cover with a sheet, blanket, or frost cloth. Not plastic touching the leaves.
4. Water the soil before dark. Damp soil holds more heat than dry soil.

What to do the next morning

Uncover plants once the sun is up and the frost has thawed. Do not uncover frozen plants in direct sun, the sudden change damages cells. Give them shade for the morning if you can.

For repeated cold nights

Wrap pots in burlap or bubble wrap for insulation around the sides. For plants you truly love, move them inside or into a garage for the worst nights. A few nights of garage life beats a dead plant.

I keep a stack of old sheets by the back door now. Five minutes of covering saves me a whole season of replanting.