Winterberry Holly
It may be January but winterberry hollies (Ilex verticillata) are still covered with berries and they’re the best-looking plant in many a Maryland garden. Because they’re native to wetlands in Eastern North America we know they like wet soils, but does that mean they need supplemental watering? Here’s what Gene Sumi has to say about that: “I know that they are tolerant of wet soils, but they are also tough enough to get by very well when soils dry out. Supplemental watering would always be desirable in drought, but I believe it is not essential to keeping them alive, once they are well-established and well-acclimated to their location. I have seen Ilex verticillata growing untended in the median strips of highways. “
Details
- Deciduous – drops its leaves in winter.
- Grows to 3-15 feet tall, depending on the variety.
- Suitable in USDA Zones 3-9.
- Densely branched, twiggy.
- Sports berries from September til mid-winter or later (‘Winter Red’ reportedly keeps its berries til March-April.)
- Inconspicuous white flowers in spring.
- Native to wetlands in most of Eastern U.S. (From Nova Scotia to Florida and west to Missouri.)
- For good berrying, need one male per 3-5 females.
- Performs best in full sun. But Gene says: “Like most hollies, the winterberry is very tolerant of shade and they will do very well in 1/2 day shade.”
- Prefers acidic soil but tolerates ordinary pH ranges.
- Attract songbirds
Care 
- Needs supplemental watering until well established and even after that, during period of long drought (like almost any plant).
- With adequate moisture, winterberries sucker – a good thing if you want them to spread, a small chore if you don’t.
- Gene on pruning: “For the most part, pruning of hollies is mostly for shaping, encouraging more fullness, and limiting the overall size of the plant” – unlike other hollies that are shaped into geometric forms.
- They have good autumn color but the leaves can look blotchy, so I asked Gene about that: “Like many plants we see as natives in the wild, the winterberry holly leaves are susceptible to damage by leaf spot fungi such as Anthracnose. Part of this may be because they lack the thicker cuticle layer on the surfaces of their leaves (unlike their evergreen sister species), which may account for their greater susceptiblility to leaf damage. The resulting damage is unsightly, but not usually life-threatening.”
Possible Landscape Uses
- Massed for effect in the woodland or in large native-plant garden.
- In shrub borders, especially if they include some evergreens.
- One source says they’re gorgeous in front of tall ornamental grasses.
Varieties widely available
- ‘Winter Red’ is the most popular in the U.S., esp for its longer-lasting berries – til March or April. To 8-9 feet tall.
- ‘Oosterwijk’ is the most popular in Europe.
- ‘Cacapon’ has a more rounded habit, grows to 6-8 feet tall.
- ‘Red Spite’ is low mounded, growing to only 3-5 feet tall.
- ‘Winter Gold’ has pinkish-orange berries. (Not gold.)
- And there’s some marketing genius at work in the combination of ‘Rhett Butler’ with ‘Scarlett O’Hara’. (With Rhett servicing up to five Scarletts!)