One of the trees most commonly associated with Christmas, like other evergreens, the holly is symbolic of immortality; its red berries stand for life and vitality as well as for blood. These scarlet berries appear in Christmas songs specifically as the blood of Christ, the redeemer. Both the masculine holly and its female counterpart, ivy, are welcomed into churches, unlike the mistletoe whose pagan origins are less easy to disguise.
The custom of bringing holly boughs into the home in the depths of winter has its origins in the original pre-Christian idea that its prickly leaves sheltered the fairy folk, who were delighted to come indoors at such a cold time of the year.
The Romans also brought holly into the house during the time of the Saturnalia, in mid December. Holly trees planted close to the home guarded the home and its occupants from evil influences, the spiny leaves of the “male” tree are a symbol of protection. Holly with smoother leaves has more female attributes. The name of the holly comes from the Teutonic Goddess Hole who was the mother of all unborn children and was responsible for naming them. However, so sacred was the holly that it was also named “the holy tree”.
The “holly king” is a symbol of a giant man, constructed from holly who carries a holly club in his hand. The seasonal counterpart to the oak king, the holly king is the guardian of the midwinter solstice. Holly stands for the letter T in the Ogham Tree alphabet, and its name is Tinne. It is ruled by the element of fire.
Ivy is traditionally seen as the female counterpart to the masculine holly, and the two plants are paired together symbolically in Christmas and Yuletide songs. Like the vine, Ivy has tendrils that enable it to climb vigorously and, like the vine, ivy is associated with Dionysus. He is often depicted using the plant to bind the nubile young ladies who would otherwise resist his advances, A wreath of ivy used to hang outside the shops as a sign that wine might be purchased there.
Ivy was believed to be able to both cause and cure drunkenness, and an old cure for a hangover was to drink vinegar in which ivy berries had been boiled. It should be stated, however, that most parts of the ivy are poisonous and it is not recommended that you try this remedy, no matter how bad the headache.
Houses with ivy growing on them are said to be protected by the maternal nature of the plant, but the clinginess of the ivy is viewed as a less attractive female characteristic. It is this same binding tendency that makes ivy an ingredient in love charms.
Ivy appears in the Ogham Tree alphabet where it is called Gort.
From the book : The Element Encyclopedia of Secret Signs and Symbols by Adele Nozedar