Do You Need a Male and Female Holly for Berries?
Usually yes. Only female holly bears berries, and it needs pollen from a nearby male holly to do so. One male can pollinate several females within about 30–50 feet. A few cultivars, such as Burford holly and Nellie R. Stevens, are self-fertile and fruit without a separate male.
In most cases, yes — you need both a male and a female holly to get berries. The female plant produces the fruit, but only after bees carry pollen to its spring flowers from a compatible male. Without that pollen, a female holly flowers but sets no berries.
The good news is that you do not need one male for every female. A single male holly can pollinate several females planted within roughly thirty to fifty feet, so one well-placed male serves a group. The male need not be the same cultivar, but it should be a compatible species and must bloom at the same time as the females — the reason winterberry is sold with matched early or late pollinators.
The exceptions are the self-fertile hollies, which set fruit on their own. Chinese holly selections such as Burford and Dwarf Burford are reliably self-fruitful, and the hybrid Nellie R. Stevens fruits heavily without a dedicated male. Where you can fit only one plant and still want berries, these are the varieties to choose.