Growing Hetz's Japanese Holly

Shrubs That Look Like Boxwood but Aren't

Japanese holly (Hetzii) with concave leaves and black berries.
David Beaulieu

Hetz's Japanese holly is an evergreen shrub, but it is a broadleaved, rather than a needled, evergreen. Its glossy, delicate leaves can make it a great choice if you are in the market for a bush with dense foliage that stays green year-round. Hetz's Japanese holly is commonly confused with boxwood. These two popular shrubs are indeed similar, but they have subtle differences in appearance as well as pollination habit.

Botany of Hetz's Japanese Holly

The taxonomy of Hetz's Japanese holly is Ilex crenata Hetzii. It is a female cultivar. The cultivar name of Hetzii is transformed into "Hetz" or "Hetz's" for use in the common plant name.

Features of Hetz's Japanese Holly

Ilex crenata Hetzii has an upright habit and grows to 3 to 6 feet tall at maturity (with a similar width). Its growth rate is moderate, and it is easily kept down to within the lower portion of that range with occasional pruning, if desired. Not grown for its blossoms (which are small and white), it does nonetheless bloom in May. Flowers are succeeded by black berries, which technically are drupes.

Landscape designers like the fact that the relatively small leaves of Ilex crenata shrubs give them a fine texture, allowing for contrast with the coarser textures of many other shrubs. These little green leaves are convex (when viewed from above) and can be quite shiny. The branches are tightly packed together.

Planting Zones, Sun, and Soil Needs

Deriving from a species indigenous to eastern Asia, Hetz's Japanese holly generally can be grown in USDA plant hardiness zones 5 through 8, although the bush's cold-hardiness is not guaranteed throughout a zone-5 area. To improve your plant's prospects of enduring a winter in zone 5, apply mulch and/or furnish it with a microclimate, perhaps with the aid of a shrub shelter.

Some gardeners grow this shrub in full sunshine, but Ilex crenata bushes tolerate shade just fine, although berry production may be reduced. It grows best in ground that drains well but will tolerate clayey soil. It also prefers a soil pH that is acidic; otherwise, its leaves may yellow.

Uses for Hetz's Japanese Holly in Landscaping

Japanese holly requires relatively little care and is a good plant for low-maintenance landscaping. As with other evergreens, this shrub will add visual interest to the winter landscape, especially if the black berries are present. Japanese holly is often used for foundation plantings and for hedges. Like boxwood, it is amenable to shearing and can be shaped into tidy forms, if desired.

Unlike English holly (Ilex aquifolium), Japanese holly does not bear spines. This is a desirable trait if you are looking for a plant that is comfortable to be around. For example, you do not want anything with thorns when landscaping around a swimming pool. On the other hand, the lack of spines may make Japanese holly less desirable for a security hedge.

Other types of Japanese holly with distinct characteristics include:

  • Helleri is a dwarf, mounding type. Several planted in a row would form a medium-sized hedge to serve, for example, as the border for a flower bed.
  • Golden Helleri is one of the shrubs with golden foliage.
  • Sky Pencil is quite different from other hollies in shape, forming a striking column. You will often see a pair of Sky Pencils flanking a front-door entryway.

A Male Is Required for Berries

Holly shrubs are dioecious, so if you have your heart set on berries, you will need to grow a male that will pollinate this female shrub. However, since Ilex crenata Hetzii is specifically a female cultivar, you can't just go out and get a male Hetz to complement it. You must use a male of a different type of Ilex crenata, including cultivars such as:

  • Bee Hive
  • Hoogendorn
  • Rotundifolia

Although pollen can travel some distance, experts recommend planting one of these males close by to improve your chances of pollination.

How to Tell Japanese Holly From Boxwood

The best way to distinguish Japanese hollies from boxwoods is to look closely at the leaves:

  • Japanese holly leaves have little teeth along their edges, while boxwood leaves are smooth (Japanese holly's scientific plant name, Crenata, is Latin for "toothed").
  • Japanese holly leaves grow in an alternating pattern along the branches; boxwood leaves are aligned in pairs.
  • Holly leaves tend to be somewhat darker and shinier than boxwood leaves.