Ilex crenata 'Helleri'

Helleri Japanese holly is a female cultivar of Ilex crenata and is a dwarf broadleaf evergreen shrub in the holly family (Aquifoliaceae). It has a slow growth rate, reaching 2 to 4 feet tall and 3 to 5 feet wide. This shrub was introduced in 1936 by J. Heller of Newport, Rhode Island. The genus name, Ilex, is Latin and originates from the name Quercus ilex, which is the holm oak. The holm oak and many shrubs in the Ilex genus have similar foliage. The specific epithet, crenata, refers to the crenate margins of the leaves. The cultivar name, 'Helleri,' is named in honor of nurseryman J. Heller.

Plant in full sun to partial shade and in acidic, moist, well-drained soil. It tolerates a wide range of soil types, including clay, but is intolerant of alkaline soils. It also tolerates pollution. It may not thrive in areas with high heat and humidity such as zones 8 and 9. The plant withstands heavy pruning and can be easily transplanted.

The species is dioecious and both male and female plants are required to produce flowers and fruits. Although this shrub is a female clone, the fruits and flowers are modestly and infrequently produced. The leaves are small, rounded, glossy, and green, and have a few crenate teeth at the tips. The young leaves appear yellowish. The 'Helleri' cultivar was named Holly of the Year for 2015 by the Holly Society of America.

This low-maintenance evergreen should be considered for planting in groups for borders or hedges or added to foundation plantings. The shrub can be pruned to manage its size so it works well in small spaces and as topiary. 

Quick ID Hints:

• Female clone, dwarf, dense, compact, rigid evergreen shrub

• Dense, tiny, glossy, rounded, evergreen leaves that are about 0.5 inches long and have a few crenate teeth at the tips of the leaves

• Infrequently produces spring flowers or fall fruits

Diseases, Insect Pests, and Other Plant Problems: This plant has no serious insect or disease problems. It may be susceptible to spider mites and nematodes.  Alkaline soils will cause the leaves to yellow. This shrub tends to struggle in hot and humid summers of the southern United States,

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common diseases and insect pests.

VIDEO created by Ryan Contreras for “Landscape Plant Materials I:  Deciduous Hardwoods and Conifers or Landscape Plant Materials II:  Spring Flowering Trees and Shrubs” a plant identification course offered by the Department of Horticulture at Oregon State University

More information on Ilex crenata.