The choice is particularly important given Riga's oft-repeated claim to be the birthplace of the Christmas tree tradition owing to evidence that in 1510 a decorated tree was burned as a way of marking Yuletide.
On Monday Riga mayor Nils Ušakovs hedged his bets by choosing not one but two giant spruce trees from the forest around Riga: one to take pride of place in the Dome Square and another to sit in Town Hall Square, close to both Ušakovs' office and the site claimed for the original Christmas tree, which is marked by a plaque.
"The lights on the trees will be lit on Sunday, 30 November, the first Sunday of Advent," Ušakovs said.
The trees, which are estimated to be around 40 years old stand 15 and 16 meters high, with the taller of the two likely to be erected in Dome Square.