Prepare your Northeast container garden for the first frost

Sort the crops first

Group tender crops with usable produce, established cool-season greens, and finished plantings. Tomatoes, peppers and basil call for different decisions from spinach or kale. Harvesting a nearly finished summer plant may be more useful than trying to protect it.

Pick sound tomatoes that have begun to color before damaging cold; use the tomato guide for indoor ripening. Frost-injured fruit should not be treated like undamaged storage fruit.

Use the forecast for the actual night

Average frost dates are planning aids, not appointments. An exposed balcony can behave differently from a sheltered patio. Decide before dark which plants will move and which remain.

Check a clear route and a stable temporary position for portable containers. Shelter during one cold night is different from a suitable long-term indoor growing location.

Distinguish fabric from plastic

Row-cover fabric varies in weight, insulation and light transmission. Follow its specifications, secure it against wind and support it where needed to avoid crushing foliage. Keep access for moisture checks.

With plastic, keep leaves away from the material and open or remove temporary protection during daytime warming. UNH warns that contact can injure foliage. Stronger enclosure means more attention to heat, not less.

Include the root zone

Foliage protection does not give a small pot the insulation of garden soil. Check drainage and pot material as part of the setup. Do not transfer an in-ground minimum temperature directly to an exposed container.

The morning after

Allow frozen leaves to thaw before handling or assessing damage. Open temporary protection as the material and warming weather require. Check moisture and stability before the next night.

If nobody can inspect an improvised enclosure the following morning, harvesting useful produce may be preferable to leaving it unattended.