Compatibe flower timing should be part of your plan when you plant hollies. Hollies work to their own natural schedules and some flower early, some late. When you purchase holly plants, they are usually sold in matched "sets" of male and female plants (about one male to each 4 or 5 females) that are bred to flower simultaneously to reduce the randomness. When you select a female with the characteristics you like, the tag on the plant should show you which male plants are compatible. The difference in timing from an early bloomer to a late one may be only a matter of a few weeks but it makes all the difference.

Plants may also be slow to flower for any number of environmental conditions. If, for instance, your less showy, male plant is kept out of sight in a shadier location, more exposed to wind or given different care than the females in terms of water, soil improvements, fertilizer or mulches, that can impact the timing of flowers and create a mismatch. 

Not all hollies need to have pollen from a male plant of the same holly species so there is a chance that yours will still bear fruit with the help of a native holly growing in a wild area or a neighbor's plant even if your male and female plants do not time with each other this year.

Courtesy of NYBG Plant Information Service