I have been at my house for 5 years, and when we moved in I noticed a beautiful holly bush by the front porch. We moved in the fall and that winter the holly was dripping with beautiful red berries. And so was the case for the next two years with no special care to the shrub. Last winter and the one before, to my dismay, there was not a single berry. I understand the whole male/female thing but there was no other holly bushes around the previous years either. I have not pruned it at all, and it has about tripled in size (at least). Could this be the problem? And also, how did I get berries before with no male plant around? Thank you.
You do need a male plant, but the male plant does not need to be all that close. I suspect that one of your neighbors had a male plant and (maybe because it did not get berries) removed it. I would suggest buying a male holly and planting it in your yard. As I said, it does not need to be right next to the female, just with 150 feet or so. If you don't like the look of the male holly, you can find an unobtrusive spot for it in your yard and it will still fertilize the female.