The day commemorates the entry of Jesus into Jerusalem on a donkey, when according to the New Testament he was greeted by crowds waving palm fronds.
In Finland, the only plant flowering at this point is usually the pussy-willow, so it is often used in Palm Sunday celebrations and decorations.
Trick-or-treat, Finnish style
Pussy-willow twigs ornamented with bright feathers and tissue paper are used by children who dress as witches, cats or bunnies and go door-to-door collecting sweets. They recite a rhyme wishing the residents health for the following year, and then give them decorated branches in exchange for Easter candy.
Reminiscent of the trick-or-treat tradition in the British Isles and North America, this practice is believed to be a mixture of Orthodox Easter blessing customs from Eastern Finland with pre-Christian rituals from Western Finland and Scandinavia.
This year's witches will have to bundle up. Temperatures are Sunday will be just above freezing through most of the country, remaining under zero in the north -- as cold as -10 degrees Celsius in some parts. Local flurries are also expected. On Monday morning, southern Finland is likely to receive snow -- perhaps as much as 10cm in Uusimaa and the south-west.
Witches in Swedish-speaking parts of the country -- mostly along the coast -- should have better luck, as they traditionally go door to door on Holy Saturday, the day before Easter.