
From the island of Shikoku in Japan, Arisaema sikokianum is an early spring flowering species with a dark purple spathe and a large white spadix with a real glow to it. Regarded as the best of all of the Arisaema species for its stunning flowers.
A few forms are available including a silver leafed form which has silvery markings in the centre of the leaf.
One of the most dramatic of all of the Arisaema species it is relatively easy to grow and a great addition to the garden.
We find that this is one of the earliest species to flower, its flowers appear at the same time as the first first foliage.


Description: Flower and Foliage
This is a plant with a hooded flower, the purple, maroon and green spathe in the form of a striped hood reaches upward and act as a backdrop to the spadix. The spadix inside the hood in a pure white, bulb shaped and it provides the dramatic wonder that Arisaema sikokianum is admired for.
The darkness of spathe seems to vary a little from plant to plant. As these are a little slow they may cost a little more than some easier varieties.
The flower itself which appears just before the foliage. The foliage itself is interesting with one, one trifolate or ‘three lobed leaf’ and one five lobed.
A mid to deep green in colour, there are forms with silver centres to the leaf as well.
Plants will reach around 24 inches ( 60cm) in height depending on conditions and actual plant.
How to Grow Arisaema sikokianum – Basic Care
This naturally a woodland plant, so a part shaded position with a moist but well drained soil works well.
Plant in the garden along with plants such as Hostas, or grow in a container, both work well.
- A soil that drains freely especially over the winter months when the plant is in dormancy is essential.
- Morning sun and afternoon shade provide a good habitat as does bright dappled shade.
- When planting mature bulbs, we suggest around 10 – 15cm deep, we grow these wonders in both the garden and in containers. We use terra cotta pots that are broad and deep.
- Plant during dormancy, so late summer onwards. In colder climate zones plant the bulbs in spring.
A relatively open potting mix for good drainage. We usually plant single large bulbs in each pot and let them ‘multiply’ for a few years before dividing and potting on.
Temperature/Humidity
Arisaema sikokianum prefers a temperate climate with moderate to cool temperatures. It generally thrives in temperatures between 10°C to 22°C (50°F to 72°F). It will tolerate slightly colder conditions but is not frost-hardy and can be damaged by freezing temperatures.
Fertilizer
We prefer to use an organic, slow release fertiliser with all Ariseama species. We tend away from animal manures with bulbs. A good layer of compost around the plants in spring is usually enough in good fertile soils.
In container try a liquid fertiliser low in nitrogen.
Ongoing Care
- It is a plant that will grow well in containers it does make a wonderful feature when in full flower.
- Mulch each spring.
- Clean up the old foliage as it dies back.
- Water in spring as new growth appears.
Propagation
- Propagation is by division of established bulbs, these will provide offsets.
- Although this is a fairly easy to propagate by division, it is a little slow from propagate from seed.
- Seed can be collected and although difficult and slow to germinate this is an excellent way of producing numbers of plants
- We dig and divide ours every four years.
Summary Information
- Botanical Name: Arisaema sikokianum
- Common Names: Japanese Cobra Lily, Japanese Jack-in-the-Pulpit, Shikoku Jack-in-the-Pulpit
- Origin: Native to Japan, specifically the Shikoku and Honshu islands
- Family: Araceae (Arum family)
- Genus: Arisaema
- Cultivar Name: N/A (Species is commonly grown without cultivar differentiation)
- Plant Type: Perennial, flowering bulb
- Height: 30 cm to 50 cm (12 to 20 inches) tall, depending on growing conditions.
- Width: 30 cm to 45 cm (12 to 18 inches) wide, forming a moderate-sized clump.
- Growth Habit: Upright, with a vase-like shape due to the spathe around the spadix and the elegant, arching leaves.
- Flowering Season: Early to Late spring to early summer (depending on the climate).
- Fragrance: Fragrance is faint, and it is a smell that is designed to attracts pollinators.
- Frost Tolerance: Moderate. Not frost-tolerant, but the plant can survive in Cool Temperate climates so USDA zones 6-9, where the winters are not too severe.
- Drought Tolerance: This plant prefers consistent moisture, although not wet winters especially in cooler climates. Ensure regular watering during spring to early summer especially during dry periods.
- Toxicity: Arisaema sikokianum is regarded as toxic to both dogs and cats if ingested.
Available for sale from the following nurseries
'Sylvan Vale' 375 Olinda Creek Rd, Kalorama, VIC.3766
Including a large range of Rare and unusual bulbs, corms and perennials
www.tonkinsbulbs.com.au