Arisaema amurense subsp. robustum
Robust cobra lily
Also known as Arisaema robustum, Arisaema ringens (misapplied)
- Height × spread
- 0.45m × 0.5m
- Position
- Tolerates full sun, likes part shade, likes light shade
- Hardiness
- Mild winter to -5C (RHS H3)
- Flowers
- Summer
Availability
Please ask in store about availability
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
This has big fat glossy green leaves, varying in number between one and five. The leaves have a crimped surface as though silken fabric has been slightly gathered. The flower, called a spathe, appears in June and July and is coloured green, usually with white or purple stripes. A hearty form that could be combined with ferns to dramatic effect in a woodland garden. This doesn't like to be too wet and cold in winter so can be a problem in heavy soils where it should be protected or lifted.
- Flower colour
- Green, Purple, White
- Foliage colour
- Green
- Fruit colour
- Red
- Variegated
- No
- Scent
- No
- Shape
- Cube
- Height
- 0.45m
- Spread
- 0.5m
- Spread in 10 years
- 0.45m
- Season of interest
- Summer, Autumn
- Flowers in
- Summer
- Evergreen
- Deciduous
- Garden style
- Exotic garden, Conservatory
- Sun or shade
- Tolerates full sun, likes part shade, likes light shade
- Soil type
- Loam (normal)
- Soil pH
- All types
- Drainage
- Moisture retentive soil, Well drained soil
- Hardiness
- Mild winter to -5C (RHS H3)
- Borders & containers
- Borders and containers
- Hazards
- Yes, potentially harmful; Humans: Harmful if eaten; skin & eye irritant
AutumnNow
Autumn - late · Outdoors
Apply a protective mulch
Protect the crown of the plant in winter in areas that are prone to frost and cold. For short term protection a fleece can be used, otherwise fill mesh sacks with masses of straw and secure them over the plant's crown.
The 'traditional method' is to put wire or other netting over the plant, layer plenty of straw on top of this and then secure the whole with more netting.
Autumn-Winter · Planting
Lift Arisaema in winter
Where cold and wet in winter, lift before frosts and keep in a frost free area. Put pot on damp sand so a little moisture will penetrate the compost.
Spring
Spring - late · Outdoors
Feed with slow release fertiliser
Apply a general purpose slow release fertiliser, spreading it around the root area of the plant as it is coming into growth. (Or apply a liquid feed at regular intervals throughout the growing season.)
This is a simple way to provide a nutrient boost as a single annual procedure.
Spring-Autumn · Outdoors
Water to keep the soil moist
For best results, this plant needs soil that is always moist. Water deeply and regularly as soon as soil appears dry. Even for established plants in the ground, a dry week can cause problems with some soils. Check plants in pots more often, especially in hot weather. Or install an automatic irrigation system which will do the hard work for you, even when you are away on holiday.
Without regular watering some plants never fully regain their beauty.
Summer
Summer · Planting
Remove offsets to create new plants
Offsets are small plants or shoots that develop around the parent plant. They should have developed a root system of their own before they are detached. They can be planted directly, or grown in pots if so small they could be 'lost' in the garden.
Offsets may be used to replace an aged parent plant, to extend or establish a colony, or can be given away or sold.
Found in
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Arisaema consanguineum subsp. kelung-insulare
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Appendixless cobra lily
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Arisaema serratum
Japanese cobra lily
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Shikoku cobra lily
Arisaema tortuosum
Tortuous cobra lily, Tall cobra lily