From the Viette's Views Gardening Blog
Such a fun time of the year to get the house and porches all spruced up for the season!
Evergreen boughs, holly, mistletoe, and …
Wait! Where are my holly berries? This is a question we often get in the fall and early winter. Many people plant holly trees and bushes so that they can cut berry laden boughs for beautiful holiday arrangements both indoors and out. But sometimes they are disappointed when the colorful berries fail to appear.
The trouble is, hollies are dioecious plants, meaning the male and female flowers are produced on separate plants. The male holly produces pollen bearing staminate flowers and the female plant produces pistillate flowers which, if pollinated, will normally develop berries.
If you only have a female holly and there is no male in the area, you will never* get berries because there is no pollen to pollinate the female flowers. If you only have a male holly, you won’t get berries either – for obvious reasons. This is true of both the evergreen hollies and the deciduous hollies.
*There are a few hollies (parthenocarpic species) that can produce berries without pollination but this is not the norm. Ilex cornuta ‘Burfordii’ is one holly that does not require pollination for fruit set.
If your hollies aren’t producing berries, the first thing to do is to check to make sure that you have both a male and female holly plant. It is best if these hollies are of the same species so that they will flower at the same time. This helps ensure good pollination which should result in a reliable berry crop. If you have NEVER had berries on your hollies, this could be the reason.
The plant label should identify whether the plant is a male or female.
Male hollies often (but not always) have male-type names like ‘Southern Gentlemen’, ‘Jim Dandy’, ‘Jersey Knight’, ‘China Boy’ …
If you don’t have a label, examining the flowers is a good way to determine whether a holly is male or female. The small, inconspicuous holly flowers appear in the spring.
One male holly can serve as a pollinator for multiple female plants. The male should be planted within a few hundred yards of the females. Bees are the main pollinators and will carry the pollen to the female flowers.
Since holly berries were produced in previous seasons, this would indicate that there are both male and female plants present in your landscape. The lack of berry production in one season could be the result of some environmental or weather related issue that affected the pollination of the flowers in the spring.
Healthy hollies will reward you with a beautiful crop of berries as long as the conditions above are met.