For many years throughout northern Europe, holly and mistletoe were prized during the winter months for their evergreen character, symbolizing life, and continuity in a time of hardness and want.

Today, they have a cherished place as holiday greenery.

Mistletoe is characterized by a distinctive forked branching habit, small leathery oval leaves and pearl-white berries.

It is hemiparasitic, meaning that it relies on a host plant for certain nutrients and water, but is also capable of photosynthesis.

In the case of mistletoe, the host plant is a deciduous tree. Mistletoe often goes unnoticed, except in winter months, when it can be seen as a ball of green foliage among the high leafless branches of the host tree.

The juvenile plant grows by photosynthesis until its roots can penetrate the bark of the tree, drawing water, minerals and some nutrients. Unless the tree is unhealthy or heavily-infested, mistletoe is unlikely to affect the health of its host.

Mistletoe’s earliest traditions are in Norse mythology where the plant was considered poisonous because the god Balder was killed by an arrow fashioned from mistletoe.

The legend has some wisdom. The berries of mistletoe are poisonous, or at least likely to cause some gastric distress if eaten.

Today, when we hang a sprig of mistletoe, the leaves are real, but the berries are generally plastic. Better to compromise a holiday custom than to risk poisoning pets and small children.

We are all familiar with the custom of kissing under the mistletoe, and for many years the plant provided a harmless excuse for a public display of affection which otherwise would have been taboo.

Christmas holly belongs to the genus Ilex, which consists of more than 400 species. Depending on the species, holly berries may be red, orange, yellow or black.

The holly that says “Christmas” is most likely to be English holly (Ilex aquifolium) or American holly (Ilex opaca). The red berries and evergreen leaves with unmistakable spiny scalloped edges are symbolic of the holiday season.

Holly bears insignificant white cup-shaped flowers in spring and early summer. The plants are dioecious, meaning that they have either male or female flowers, and only the female plant bears fruit.

For best results, a male and female should be planted within 30 to 40 feet of each other. Newly-planted holly may not bloom for several years, so be sure to purchase your plant from a reputable nursery that can assure you of its gender.

Hollies grow best in full sun and prefer moist, well-drained soil. They will tolerate shade but will not grow to their full potential. Holly’s natural growing habit is an attractive pyramidal shape, making it an ideal year-round focal point in the garden.

Holly can be pruned during December and the cuttings can be enjoyed throughout the holiday season. Holly leaves tend to drop if they are brought indoors, so it is best to use the cuttings outdoors.

If holly is overgrown, some experts recommend the “hat rack” method of pruning. This technique is considered inappropriate for pruning most trees, but is a successful method used to rejuvenate holly.

In late winter, cut the branches back by one-half to three-fourths. The result will resemble a hat rack, and will be a complete eyesore, but the plant will rebound fully in two to three years. Though reduced in size, the foliage will be far more abundant.

While no plant is completely deer resistant, the American holly is generally not browsed by deer.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613.