I have to admit that I made a mistake. I took for granted the beauty and appeal of the winterberry holly. Winterberry (Ilex verticillata) has gained popularity in recent years as an ornamental landscape plant. Since moving to coastal Maine, I see it growing all over the edges of woodlands and wet areas. As a person who loves plants, seeing an ornamental plant growing in its native habitat has a surreal quality to it. Seeing winterberry, for instance, shows you where a plant can survive and thrive, without being planted, pruned, fertilized, and watered.
Last week, while riding down the road, we saw two pickup trucks pulled over along side of the road. As we passed, I could see that the trucks were already full of cut evergreen branches. I could also see why they had pulled over and parked. There, beside of the trucks, were a couple of folks pruning red-fruit laden branches of wild, winterberry hollies growing from the ditch banks. Then the lightbulb went off. Any plant that would make people pull over, is certainly worth more use in the landscape, especially one that is native to the eastern US. Plus, with the fruit set, you can have free Christmas decorations for your home. The bright, red fruits of winterberry holly are a welcome, winter decoration to the outdoor garden and bedecked indoors.
There are two important things to consider when selecting winterberry hollies. The first is that they are deciduous. Growing up in central North Carolina, outside of Raleigh, the holly I most often saw in the woods was the evergreen American holly, Ilex opaca. I did not know that this plant had a smaller relative that lost its leaves, until we had to learn Ilex verticillata in our college plant identification classes. The second thing to know is that they are dioecious. Dioecious literally means “two households” and in this case, that there are male and female plants. So, if you want the beautiful berries for this queen of the winter landscape, you have to plant a male counterpart nearby. The normal ratio is one male pollinator for every 12-15 female plants.
Numerous cultivars of winterberry holly exist. These cultivars are broken down into three main groups. These groups are: northern US varieties which flower from May-June, southern US varieties which flower from June-July, and hybrid winterberries (Ilex verticillata x Ilex serrata). Knowing which plant your group falls in is important as you need to have the male flower at the same time as the female in order to achieve best fruit set in the fall.
Thankfully, quite a bit of research has been done on winterberries. Longwood Gardens conducted a 20 year trial of different winterberries and published their findings here. My favorites include: ‘Sparkleberry‘ (a hybrid), ‘Winter Red‘ (a southern selection), and ‘Red Sprite’ (a northern selection and above). For each female plant, there is an appropriate male. The Manual of Woody Landscape Plants by Dr. Michael A. Dirr is a valuable reference for sorting out which male pollinator is best for which female plant. Often, the plant breeders have adopted studly names for the male pollinators such as: ‘Apollo,’ ‘Jim Dandy,’ ‘Southern Gentleman,’ and my favorite ‘Rhett Butler’ who of course is the pollinator for the female ‘Scarlet O’Hara.’
As for planting conditions, winterberry grows best in a slightly acidic soil (4.5-6.5 pH) that stays continuously moist, yet well drained. It will survive in drier sites but will struggle and look thin, chlorotic, and produce less fruit.
Do you have winterberry holly in your garden? If so, which one and do you like it? - Rodney
Images: Flickr, Rodney Eason