Jennifer Schultz Nelson
Extension Educator, Horticulture
Probably the only question anyone ever asks me about holly is why theirs doesn't have berries on it. Everyone seems to plant holly because they want berries. I can see why–in an otherwise dreary winter landscape, a little splash of red is a welcome sight.
The trick to producing the highly sought after red berries is realizing that holly is another one of those plants that is dioecious, literally "two houses", meaning there is a separate male and female plant. Only the female plant will produce the berries, which develop after the female flowers are pollinated by the male flowers. Inside each berry is at least one seed for a new holly. Botanically speaking, holly berries are more like a peach, where the seed(s) is more like a pit, and truly deserve the title "multiseeded drupe" rather than berry. Although technically incorrect, using the term berry in reference to holly fruit will avoid confusion.
Complicating matters is that not all hollies are completely dioecious. Some are able to produce berries without pollination, though they are seedless, and less are produced than when flowers are pollinated. This phenomenon is called parthenocarpy, which comes from the Greek "carp" meaning "fruit" and "partheno" meaning "without fertilization".
The holly cultivar I ended up purchasing for my yard is 'Merry Berry', which is one of these parthenocarpic types. Honestly, I didn't know this when I bought them. It was late October, they were marked down to $1.50 per shrub, and I saw berries on each one of them. I could afford to buy then and do research later. At worst I'd have to sneak in a male holly somewhere in the landscape to provide pollen. I still may end up doing that, since while I have berries, berry production is much greater on these types with pollination.
Holly is a member of the genus Ilex. This genus has over 700 individual species distributed worldwide. Only about 150 of these species are cultivated for landscapes, and of these only about 40 species would be considered "common". There are literally thousands of cultivars developed from the cultivated species. Nearly all of the hollies grown today originated in China, Japan, Europe, or North America.
Generally speaking, hollies prefer a sunny location with well-drained soil. Some species have preferences as far as moisture and pH, but one reason they are so popular with homeowners is that although they have preferences, usually they will tolerate a wide range of conditions and stresses often present in home landscapes.
Ask anyone to draw a holly leaf and berries, and you will probably get an elongated shiny green leaf with spines arranged along the margins and a cluster of red berries. This is a good generalization, but many hollies do not look like this at all.
It is pretty standard for holly leaves to have spines, but not a rule. There are cultivars that have smooth leaves that are easily mistaken for boxwood. Others are so spiny it makes handling fallen leaves a painful exercise. Some hollies are evergreen, others lose their leaves in the fall. Leaf color also includes cultivars with a wide range of variegation. Also, while it is true that many hollies have red fruits, there are others with orange, yellow, or even black or white fruits.
Overall size also varies widely in hollies. Many times holly is part of a shrub border. Some are naturally small and compact. But many cultivars, if left to their own devices, would assume statures of fifteen feet or more. Some have reportedly reached heights of eighty feet or more.
As is with many Christmas traditions, the use of holly during this season has its roots in pagan customs dating back thousands of years. Many scholars believe ancient Druids revered holly because it was the plant that "sun never forgot", since it remained green throughout the winter in the otherwise leafless forest.
Ancient Romans believed the plant represented good will, and often gave it to newlyweds to congratulate them. They also used holly liberally during their Saturnalia celebrations, which were held during what is now the month of December and honored Saturn, the god of sowing and husbandry.
Asian cultures found reason to revere holly, especially as a symbol of fertility and divine power. In particular the Chinese also used holly during their New Year celebrations which occur around February. Some believe the name holly came from an original name of "holy tree". Early Christians believed that the spiny holly leaves symbolized Christ's crown of thorns, and the red berries were drops of His blood.
Celtic mythology is filled with images of holly, whether it is within celebrations of the winter solstice, where the mysteriously green holly offers a promise of spring's renewal, or the belief that the holly bush offered protection from evil spirits.
It was customary for people to cut holly branches to bring indoors during the dark days of winter to protect the home's residents. Supposedly whether a male or female holly was selected predicted who would "rule the home" for the coming year.
The power of holly extended beyond the winter holiday season. Few Celts would voluntarily cut a holly bush completely down, for fear of losing its protection. Legends told that the prickly leaves of holly kept evil spirits from accessing a man's property. In 1861 the Duke of Argyll had a proposed road rerouted in order to avoid cutting down an old holly bush.
Another ancient legend was holly's ability to protect a building from lightning strikes. Scandinavian myths say that holly originally belonged to Thor, god of thunder and lightning. Since the holly was so closely associated with Thor, Scandinavians believed that planting holly near a home would protect it from lightning strikes. The growth pattern of many hollies can be erratic and crooked, enhancing the association with lightning bolts. There is some scientific evidence that holly can withstand a lightning strike better than other trees or shrubs, perhaps because of their distinct leaf shapes.
Holly has uses in modern society besides winter decorations. Holly wood takes dye extremely well, and is often used for inlay work in musical instruments and furniture. Since it takes dye so well, it is often used as a substitute for ebony, and makes up the black keys on many pianos today.
Wherever holly grows, it seems like myths and legends grew along with the plant. Considering often times it was the only thing green in the winter landscape, and had fruit, it comes as no surprise that ancient people attached significance to this plant. Even as modern people with the world at our fingertips, isn't it funny how signs of life like holly and its berries amid the cold winter still get people's attention? I hope that never changes.