Practical
Plants

Ilex crenata

Japanese Holly

No photo available

Taxonomy and growth

Genus
Ilex
Life cycle
perennial
Foliage
evergreen
Woodiness
woody
Growth rate
slow
Height
5 m
Spread
3 m
Fertility
self sterile
Flower type
dioecious
Pollinators
Bees

Uses

Toxicity

Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.

Although no specific reports of toxicity have been seen for this species, the fruits of at least some members of this genus contain saponins and are slightly toxic. They can cause vomiting, diarrhoea and stupor if eaten in quantity[8].

Edible uses

Fruit[2][4]. No further details are given, but some caution is advised[K].The fruit is about 5mm in diameter[7].

Plant part
Fruit

Material uses

Very amenable to trimming, this species is often grown as a hedge in N. America and Japan. It can also be used in topiary[5].

Ecology and functions

Hedge

Environment

Range
E. Asia - Japan, Korea.
Habitat
Thickets, woods and wet places in lowland and mountains all over Japan[9].
Light
full sun
Shade tolerance
light shade
Water
moderate
Hardiness
Zone 6+
Soil textures
sandy, loamy, clay
Soil pH
acid, neutral, alkaline
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

Seed - best sown as soon as it is ripe in the autumn in a cold frame. It can take 18 months to germinate. Stored seed generally requires two winters and a summer before it will germinate and should be sown as soon as possible in a cold frame. Scarification, followed by a warm stratification and then a cold stratification may speed up the germination time[10][11]. The seedlings are rather slow-growing. Pot them up into individual pots when they are large enough to handle and grow them on in light shade in a cold frame for their first year. It is possible to plant them out into a nursery bed in late spring of the following year, but they should not be left here for more than two years since they do not like being transplanted. Alternatively, grow them on in their pots for a second season and then plant them out into their permanent positions in late spring or early summer. Give them a good mulch and some protection for their first winter outdoors. Cuttings of almost ripe wood with a heel, August in a shaded position in a cold frame. Leave for 12 months before potting up. Layering in October. Takes 2 years.

Cultivation

Succeeds in most soils so long as they are not water-logged[7]. Prefers a moist loamy soil[1]. Fairly slow growing. Plants are hardy to about -20°c[6]. A number of named varieties have been selected for their ornamental value[5]. Resents root disturbance, especially as the plants get older[3]. It is best to place the plants into their permanent positions as soon as possible, perhaps giving some winter protection for their first year or two[K]. Any transplanting is best done in May or, preferably, in September. Dioecious. Male and female plants must be grown if fruit and seed is required.

References

  1. F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00

    ↩

  2. Tanaka. T. Tanaka's Cyclopaedia of Edible Plants of the World. Keigaku Publishing 1976-00-00

    ↩

  3. Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981-00-00

    ↩

  4. Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984-00-00 ISBN 3874292169

    ↩

  5. Thomas. G. S. Ornamental Shrubs, Climbers and Bamboos. Murray 1992-00-00 ISBN 0-7195-5043-2

    ↩1↩2

  6. Phillips. R. & Rix. M. Shrubs. Pan Books 1989-00-00 ISBN 0-330-30258-2

    ↩

  7. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

    ↩1↩2

  8. Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J Illustrated Flora of North Central Texas Botanical Research Institute, Texas. 1999-00-00 http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm

    ↩

  9. Ohwi. G. Flora of Japan. (English translation) Smithsonian Institution 1965-00-00

    ↩

  10. Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948-00-00

    ↩

  11. McMillan-Browse. P. Hardy Woody Plants from Seed. Grower Books 1985-00-00 ISBN 0-901361-21-6

    ↩

Edit this page