Young seedlings can suffer from a cold night even when the daytime weather is mild. A breathable cover reduces heat loss while allowing air movement and preventing direct contact with wet foliage.
Prepare before sunset
Water the soil if it is dry, remove weeds, and set supports before temperatures fall. The cover should rest on stakes or hoops rather than crush the plant.
Use a breathable material
Choose horticultural fleece or another purpose-made cover. Avoid sealed plastic touching leaves, especially when condensation can collect.
Secure the edges
Anchor the cover against wind while leaving room for the plant to grow. Close gaps near the soil line without trapping stems.
Remove it in the morning
Vent or remove the cover after temperatures rise and sunlight returns. Inspect the seedling for moisture damage and adjust the support for the next cold night.