Japanese holly 'Helleri'
Ilex crenata 'Helleri' · Aquifoliaceae
A low, dense mound of tiny, dark, evergreen leaves that looks like a boxwood. It is slow, and stays below a metre for years without pruning.
- Size
- 3 ft tall, 4 ft wide
- Zones
- 5 to 8
- Light
- Full sun to part sun
- Flowers
- Grown for its leaves
- Pets
- Toxic (mild)
- Job in a bed
- Anchor
A bed built around Japanese holly 'Helleri'
The planner designed this bed around Japanese holly 'Helleri' when this page was made: a 16 × 8 ft (4.9 × 2.4 m) English border in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why Japanese holly 'Helleri' stands where it does.
The plants
- 1 Japanese holly 'Helleri' × 1, dark green leaves
- 2 Verbena 'Homestead Purple' × 8, purple
- 3 Carpathian bellflower 'Blue Clips' × 8, blue
- 4 Sweet coneflower 'Henry Eilers' × 4, yellow
- 5 Wild quinine × 8, white
- 6 Winter heath 'Kramer's Red' × 3, pink
- 7 Jonquil × 12, yellow
- 8 Ornamental onion 'Purple Sensation' × 5, purple
- 9 Surprise lily × 8, pink
Why this plant
- The only plant grown for its leaves. Leaf lasts all season, where a flower lasts a few weeks.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So does winter heath 'Kramer's Red'.
Why here
- In the middle. At 3 ft it is seen over verbena 'Homestead Purple' (10 in) in front of it.
- One plant, alone. A shrub is seen as an object, and needs clear ground around it.
- Fine leaf against bold. Wild quinine is beside it: the strongest contrast of leaf there is.
Why now
- Here for its leaves, all year. They cover the 8 weeks between early March and late November when nothing on the plan is in flower.
- One of two evergreens. They are what the bed has to show from November to March.
Planned as an English border: 6 of the 8 groups (75%) are drifts, longer along the bed than they are deep. The bold leaves of wild quinine are set against the fine leaves of Japanese holly 'Helleri', the kind of contrast that keeps a bed from blurring. Not everything here depends on flower: Japanese holly 'Helleri' earns its place with leaves.
The planner's own design check: 13 Excellent, 4 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where Japanese holly 'Helleri' goes in a border
At 3 ft it belongs in the middle of a bed. In the planner's ten height classes it is medium tall (2½ to 3 ft).
Its job: anchor. A shrub that gives the bed permanent structure. Planted singly, as soon as the front edge is laid; everything else is arranged around it.
Use it where you want the look of boxwood without boxwood blight. It needs acid, well-drained soil, and suffers in wet clay.
- A boxwood substitute
- Low hedges and foundation planting
- Evergreen structure in a border
What to plant with Japanese holly 'Helleri'
Plants recorded as good partners for it, and what each pairing does:
- Daylily: adds the flowers, late June to early August.
- Cranesbill 'Rozanne': adds the flowers, early June to early October; low enough (18 in) to stand in front of it.
- Salvia 'May Night': adds the flowers, late May to mid July; spires rising out of its mound.
Questions about Japanese holly 'Helleri'
Does Japanese holly 'Helleri' need sun or shade?
Japanese holly 'Helleri' grows in full sun (6 or more hours of direct sun a day) and part sun (4 to 6 hours of sun, including some afternoon sun).
It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells. Once settled in, it stands drought.
What zones does Japanese holly 'Helleri' grow in?
USDA zones 5 to 8. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
How far apart should Japanese holly 'Helleri' be planted?
3½ ft (100 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 4 ft (120 cm), so a group knits into one patch.
It grows 3 ft (90 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many Japanese holly 'Helleri' plants do I need?
At 3½ ft apart, set out in staggered rows:
- 1 to fill 10 square feet (about 1 m²)
- 4 for a single row 10 ft (3 m) long
- 3 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, planted singly: it is the bed's structure, and everything else is arranged around it.
In the bed above, the planner used one in one group.
Is Japanese holly 'Helleri' poisonous to dogs and cats?
Yes: mild toxicity to people, dogs, cats and horses. The berries and leaves cause vomiting and diarrhoea if eaten.
Rated from NC State Extension. Where references disagree, the more cautious rating is used.
Is there a pet-safe plant like Japanese holly 'Helleri'?
These come closest to doing what Japanese holly 'Helleri' does, and no toxicity is recorded for them:
- Mugo pine 'Mops': the same job in a bed; 8 in narrower.
- Arborvitae 'Hetz Midget': the same job in a bed; 4 in narrower, wants moist soil.
- Box honeysuckle 'Baggesen's Gold': the same job in a bed; belongs at the back, not in the middle, 12 in taller.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat Japanese holly 'Helleri'?
Mostly not. NC State lists it as resistant to deer. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What does Japanese holly 'Helleri' look like in winter?
Japanese holly 'Helleri' keeps its dark green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone.
Is Japanese holly 'Helleri' good for bees and butterflies?
Japanese holly 'Helleri' is visited by pollinators, bees and specialist bees.
More Ilex
- Blue holly Ilex x meserveae
- Blue holly 'Blue Princess' Ilex x meserveae 'Blue Princess'
- Burford holly Ilex cornuta 'Burfordii'
- Dwarf yaupon holly Ilex vomitoria 'Nana'
- Inkberry Ilex glabra
- Inkberry 'Gem Box' Ilex glabra 'SMNIGAB17' (Gem Box)
- Inkberry 'Shamrock' Ilex glabra 'Shamrock'
- Japanese holly 'Sky Pencil' Ilex crenata 'Sky Pencil'
- Japanese holly 'Soft Touch' Ilex crenata 'Soft Touch'
- Winterberry Ilex verticillata
- Winterberry 'Berry Poppins' Ilex verticillata 'FARROWBPOP' (Berry Poppins)
- Winterberry 'Red Sprite' Ilex verticillata 'Red Sprite'
- Winterberry 'Winter Red' Ilex verticillata 'Winter Red'
In these guides
Every fact on record
- Type
- Shrub
- Size
- 3 ft (90 cm) tall, 4 ft (120 cm) wide
- Plant
- 3½ ft (100 cm) apart
- Height class
- Medium tall (2½ to 3 ft)
- Place in the bed
- Middle
- Flowers
- None: grown for its foliage
- Leaves
- Fine texture, evergreen; dark green
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 5 to 8
- Light
- Full sun, part sun
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Aquifoliaceae
- Comes from
- East Nepal to Temperate East Asia, Japan and Korea
- Attracts
- Pollinators, bees, specialist bees
- Stands up to
- Deer, drought, pollution
Checked against NC State Extension. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.