As the holiday season draws to a close, it is the perfect time to consider holly. Not only is it the plant that gives Christmas its red and green color scheme, it brings year-round interest to the landscape. During winter these evergreen shrubs and trees are focal points for many homes, the red berries brightening the short days.
Hollies are dioecious, which means that male and female flowers are borne on different plants. In order to have berries, there must be at least one male plant to pollinate the females. Some female hollies are parthenogenetic, a term from Greek referring to virgin births. The very popular holly Nellie R. Stevens (right) bears fruit without male flower pollen.
Nellie is a hybrid between Chinese and English hollies. This tree is frequently planted at the corner of a house. Its pyramidal profile, shiny leaves and red berries make it a great specimen plant. However, most homeowners struggle to keep it in bounds for it grows 15 to 25 feet tall and is 8 to 12 feet wide. It is terrific when used as a hedge.
English holly is on the noxious weed list in Washington State and considered invasive from California to British Columbia. In other words, it is as welcome out West as privet and kudzu are here. A popular example of a Chinese holly is the Buford variety. Japanese hollies dislike hot summers so are not good choices for our area. Both Yaupon and American hollies are native to the southeastern forests, so do well in our landscapes.
Hollies are the most broadly adaptable of evergreen tree species. They like a site which is sunny or partly shaded and slightly acid soil. Plant them in either spring or fall. Not plagued by pests or many diseases, they are easily maintained with a spring fertilization and a layer of mulch. Some leaf loss in spring is normal.
To ensure plenty of fruit on hollies, proper pruning is important. Holly blooms on old wood. A gardening rule of thumb is to prune these shrubs after flowering, but holly flowers are not very showy so you may prefer to prune after the berries appear. Though evergreen, hollies are dormant in winter. It is OK to use some branches in your holiday decor, or wait until later in winter to shape up the shrub.
Not all hollies are evergreen. The best known of the deciduous ones is winterberry, Ilex verticillata, the stems of which are covered in red berries throughout winter. It is native to wet woods and bogs from Maryland to Michigan. It tolerates dry sites as well as soggy ones so can be a real problem solver in a woodland garden. Winterberry does need annual renewal pruning. This is done by removing up to one-third of the old stems.
The fossil record tells us that hollies were widespread by the end of the Cretaceous Period though the ancestor of modern species evolved later. Many members of the Ilex clan became extinct at the end of the last ice age.
Amazing to think that mammoths and the first Americans were familiar with far more hollies than we are.
Master gardener Ann Bartlett gets through the long, gardenless winter however she can, as can be evidenced by the above photo. The Planet has no room to talk. You can contact Ann at firstname.lastname@example.org.