According the US National Arboretum

The U.S. National Arboretum presents 'Sparkleberry' holly, an improved deciduous holly for the landscape. 'Sparkleberry' produces a striking and long-lasting display of brilliant red winter berries on large plants of upright form. Planted at woodland's edge or in a massed grouping, 'Sparkleberry' will add sparkle to your landscape! 'Sparkleberry' is a female selection and requires a pollinator for good fruiting. A male selection of the same cross, Ilex 'Apollo', was released as a pollinator for 'Sparkleberry'.

Below is the link to the site where I found this information. Hope this helps!

Here is a link that might be useful: USNA

Does Southern Gentleman bloom at the same time as your Sparkleberry? That is the key, the male and female hollies must have overlapping bloom times. And then you need pollinators, namely bees, to do the actual pollinating, so limiting the use of chemicals is also important. :0)

Thanks for the suggestions but Southern Gentleman does bloom at the same time. That variety was recommended by the nursery we bought the Sparkleberry from. It is also recommended in a book on trees and shrubs I have. I use no poisons so we have lots of have bees and other insects.

I suspect a cultural problem since the Sparkleberry hasn't grown much over the years and is only 5 feet tall.

OR just a thought, but have you looked closely at the flowers? Maybe you got a wrong-sexed plant. There are some pictures on this link that might help you determine the sex, since the flowers are very similar.

Here is a link that might be useful: Male vs. Female Holly

I just realized, you did say you had a handful of berries, so your Sparkleberry is for sure a female shrub. They do prefer moist, acidic soils. I am having a devil of a time with my inkberries, they get leaf spot and are growing poorly in my somewhat alkaline conditions. Have you tried Hollytone? It's completely organic. That's what I've been trying. Or maybe try a Winter Red instead, you could just have a dud. :(

chrisinerie:

If everything that you've listed is going on...

Âyour 'Sparkleberry' and 'Southern Gentleman' are blooming fine and at the same time

Âyou have lots of bees and other insects

Âboth plants are true to name (one is female, the other male)

...then the poor 'Sparkleberry' must not be able to sustain the ripening fruit through the season. To correct potential deficiencies, I'd give your winterberries a good shot of a mid-level nitrogen fertilizer and plenty of moisture throughout the growing season. A timed-release fertilizer brand with numbers in the 14-14-14 range would work fine.

If the plants are in such a location that watering is not possible, then I'd move them to a sunnier and wetter spot.

Your silver maple is probably just taking all/most of the available ground moisture during the critical fruit set period, and will continue to do so - as well as continue to create more shade which will further retard the growth and production of your winterberries.

Life is too short to wait. Make the adjustment, and enjoy!

Dittos on the move recommendation.

If the silver maple's roots are able to reach the hollies, watering the plants may encourage the root growth of the maple. I've had plants literally strangled by silver maple roots - you may find evidence of that when you dig up the plants to move them.