The weather change often here in Texas. Just as in Scandinavia. Except that in Scandinavia we cover plants for several months at a time.
But now it is around 30*F (around 5*C) here in Houston and the cold spell will remain several days ahead. So last night we ran out and covered some of the most delicate plants. These are plants as Paradise flower (Strelitzia reginae), Angels trumpet (Brugmansia), Arrowhead plant (Syngonium phodophyllum), Bougainvillea and newly planted citrus trees. Lime and lemon trees are the least hardy of the citrus types, but since all the trees are planted this winter, aka not well established yet on their growing place, they are all wrapped up. I use what I have on hand, garden fleece, some lined bubble wrap that I kept from our moving here, burlap, and some paper sacks.
For prolonged frost fleece cover will be insufficient, but against cold winds and brief periods of frost, the wrapping will prevent new shoots to get freeze damage, and hopefully prevent that the plant is generally weakened by the cold. Plastic is not really recommended since it creates condensation and prevents air circulation, but for some days it’s fine just as long its not become too hot daytime.