Holly Days

By Jeff Osborne, Forest Stewardship Program Associate

As the new year nears, it seems you would have to make a conscious effort not to hear about or see the foliage or fruit (drupes) of some type of holly, in print or in real life. They are often depicted on greeting cards, store and home decorations, and awesome festive sweaters. Some holly fruit really stand out in wetlands and landscaping during this time of year. Aside from American holly, which has a few exotic lookalikes, there are several other hollies native to Pennsylvania. Hollies can be deciduous or evergreen, shrub or tree; individuals have either female or male flowers, and their drupes, which are not edible for humans, can be red, black, or other colors. Let’s take a closer look at a few native hollies.

Winterberry, Ilex verticillata, is currently brightening many wetlands with its red fruit covering its leafless branches. It can also be an element in landscaping, with several cultivars available from commercial nurseries. The fruit can remain on the stem bright red for months, so the fruit laden branches are often incorporated into decoration. This shrub is used by birds throughout the year.

This picture shows a fruit laden winterberry.
John Ruter, University of Georgia, Bugwood.org

Mountain holly, Ilex montana, is a fairly common deciduous shrub that is generally less showy than winterberry and can be found as an understory shrub in mature forests and in forest gaps and edges. The leaves tend to be larger than winterberry and also turn yellow in autumn shortly before they fall.

Photo of mountain holly showing flowers that
are similar to other hollies.
Steven Daniel newyork.plantatlas.usf.edu

Inkberry, Ilex glabra, is an evergreen shrub that tends to grow in sandy woods and on the edge of wetlands. It is a smaller holly, usually reaching only six feet in height and tends to form colonies by spreading from root suckers. This shrub, like American holly, has a high flammability rating, so it should be planted at least 30 feet from structures.

The above picture shows the dark fruit and thick obovate leaves of the inkberry.
Rebekah D. Wallace, University of Georgia, Bugwood.org

American holly, Ilex opaca, is a medium stature evergreen tree. It can grow past 20 inches in diameter and 60 feet tall. It has thick pointy foliage that deer have little interest in eating. American holly has minor insect and disease pests. Where they are planted in landscaping, they may develop issues due to unsuitable soil pH or nutrients. American holly is similar to English holly, Ilex aquifolium, but can be distinguished by the foliage. The native tends to have more ridged spines and the exotic tends to have a deeper curved sinuses between the spines.

An American holly tree in York County, PA.
It is estimated to be over 300 years old.
It is about 28 inches in diameter and was
over 60 feet tall before its recent top die-back.
Photo taken in the late 1970s by
Pennsylvania Power and Light Company.

American holly showing its red fruit and thick
prickly leaves.
John Ruter, University of Georgia, Bugwood.org

 If you are interested in propagating hollies from seed, be patient. The seed may not germinate for three years and even then may have germination rates of only around 30%. A great resource from which to learn more is the USDA Forest Service’s Woody Plant Seed Manual, which can be found online. The difficulty of seed germination is a reason many hollies are propagated from vegetative cuttings. Also, to encourage fertilized flowers on female plants, male plants should be planted within 40 feet of them.

Enjoy the hollies, both in decorations this time of year and out in the wild!