The wreath is a ring made of flowers, leaves, fruits, cones, twigs, etc. It is an old Pagan symbol and to associate it with a cross may at first appear strange. Yet we must remember - the cross too, was used by Pagans long before the arrival of Christianity.
Germanic tribes used wreaths in the winter and decorated them with small candles. This was to encourage the onset of spring - the circular wreath representing the turning seasons and the candles representing the warmth of the sun. (See also Midsommarstang Cross)
Wreaths were worn like a crown, perhaps in honour of the Sun god, by the Romans to celebrate various festivals. In particular, they were worn by officers in military parades. This custom continues to this day, in the form of a wreath or part-wreath decorations on most caps and helmets of military officers around the world.
Evergreen leaves symbolize life, even in the severest winters, and the circle symbolizes immortality. The ancient Greeks used a wreath made of laurel of olive leaves as a winner's crown in the Pythian Games. This has been carried forward into various designs used by today's Olympic Games (although clearly absent from the ridiculous London Olympics logo for 2012.)
Because of its association with the everlasting life of the soul, wreaths are common decorations for funerals, graves and monuments, both civil and military. See also the Funeral Cross and Burial Cross. (We feel the London Olympics logo deserves a burial wreath.)
For funerals at sea, a wreath is tossed into the water like a lifebelt, symbolising the hope that although the body has gone, the soul might be saved.
The symbol was adopted by Christians in the Middle Ages as a decoration for Advent, helping people focus on the true meaning of Christmas.
A popular evergreen at Christmas time is the holly leaf. This has prickly edges and represents the crown of thorns used at Jesus' Crucifixion. (The word 'holly' could well originate from 'holy' - see Holy Cross.) The candles represent Jesus who came to the world as a light over darkness (John 3:19-21). The wreath symbolizes everalasting life, guaranteed to those who accept Christ's salvation.
Where a cross itself is made from leaves, such as the Christmas Cross, it is sometimes called a Wreath Cross. But this is a misnomer; by definition, a wreath is circular.
The wreath may well have begun as a Pagan symbol but there is nothing wrong about Christians copying this. The Bible mentions several occasions where wreaths are used in celebrations. The round circle of the wreath indicates eternity and a celebration of eternal salvation while the green colour represents growth and life, pointing toward the role of the Holy Spirit in our salvation and life eternal.