How far apart should I plant Eastern Cape giant cycad?

About 3 m (10 ft) apart, centre to centre. A mature plant spreads 2.5–4 m (8.2–13 ft).

Does Eastern Cape giant cycad need full sun?

Part sun to part shade: at least 4 hours of direct sun a day.

How much water does Eastern Cape giant cycad need?

Moderate water. Drought tolerance is moderate and waterlogging tolerance none.

How cold-hardy is Eastern Cape giant cycad?

It tolerates about -3 °C (27 °F) once established, roughly USDA zone 9.

When does Eastern Cape giant cycad flower?

From about July for 4–9 weeks (northern hemisphere; later in cold climates, earlier in warm ones).

Is Eastern Cape giant cycad poisonous to cats and dogs?

For cats it is severely toxic; for dogs severely toxic; for people severely toxic. Cycads contain cycasin and other neurotoxins; seeds are the most dangerous and cause liver failure in dogs.

What grows well with Eastern Cape giant cycad?

There is no well-documented companion pairing for Eastern Cape giant cycad. Group it with plants that like the same sun (part sun to part shade) and water (moderate).

Eastern Cape giant cycad Encephalartos altensteinii

Eastern Cape giant cycad (Encephalartos altensteinii) is an evergreen perennial tree in the Zamiaceae family, native to Eastern Cape and KwaZulu-Natal, South Africa (coastal forest and valleys). It grows 2–7 m (6.6–23 ft) tall and 2.5–4 m (8.2–13 ft) wide, wants part sun to part shade and moderate water, and is hardy to about -3 °C (27 °F). Space plants about 3 m (10 ft) apart.

Plan Eastern Cape giant cycad in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.

Eastern Cape giant cycad at a glance

Type	Perennial tree, evergreen
Family	Zamiaceae
Mature height	2–7 m (6.6–23 ft)
Mature spread	2.5–4 m (8.2–13 ft)
Spacing	3 m (10 ft) centre to centre
Sun	Part sun to part shade, at least 4 h of direct sun a day
Water	Moderate; drought tolerance moderate, waterlogging tolerance none
Soil pH	5.5–7.5
Cold hardiness	About -3 °C (27 °F) once established (roughly USDA zone 9)
Heat stress	Likely above about 40 °C (104 °F)
Flowering	from about July for 4–9 weeks (northern hemisphere; later in cold climates, earlier in warm ones)
Wind tolerance	Moderate
Pollinator value	None
Edible	Not grown as food
Native to	Eastern Cape and KwaZulu-Natal, South Africa (coastal forest and valleys)
Common in gardens of	🇿🇦 South Africa

Is Eastern Cape giant cycad toxic?

People: severely toxic
Cats: severely toxic
Dogs: severely toxic
Parts: seeds, all parts

Cycads contain cycasin and other neurotoxins; seeds are the most dangerous and cause liver failure in dogs.

If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.

Companion planting: what to grow with Eastern Cape giant cycad

No well-documented helpful pairing. Group it with plants that like part sun to part shade and moderate water.

See Eastern Cape giant cycad in a botanical garden

It grows in these sample gardens, which you can walk through in 3D:

UC Botanical Garden, Berkeley (2 plants)
Nong Nooch Tropical Botanical Garden (3 plants)
Fairy Lake Botanical Garden (1 plants)
Kirstenbosch (4 plants)
Kew: glasshouses and rock garden (1 plants)

Questions about Eastern Cape giant cycad

How far apart should I plant Eastern Cape giant cycad?: About 3 m (10 ft) apart, centre to centre. A mature plant spreads 2.5–4 m (8.2–13 ft).
Does Eastern Cape giant cycad need full sun?: Part sun to part shade: at least 4 hours of direct sun a day.
How much water does Eastern Cape giant cycad need?: Moderate water. Drought tolerance is moderate and waterlogging tolerance none.
How cold-hardy is Eastern Cape giant cycad?: It tolerates about -3 °C (27 °F) once established, roughly USDA zone 9.
When does Eastern Cape giant cycad flower?: From about July for 4–9 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
Is Eastern Cape giant cycad poisonous to cats and dogs?: For cats it is severely toxic; for dogs severely toxic; for people severely toxic. Cycads contain cycasin and other neurotoxins; seeds are the most dangerous and cause liver failure in dogs.
What grows well with Eastern Cape giant cycad?: There is no well-documented companion pairing for Eastern Cape giant cycad. Group it with plants that like the same sun (part sun to part shade) and water (moderate).

Sources and evidence

Evidence grade B (B: extension service or peer-reviewed).

Kew Gardens: Palm House, Temperate House, Rock Garden and Mediterranean Garden, Royal Botanic Gardens, Kew
PlantZAfrica, South African National Biodiversity Institute
IUCN Red List of Threatened Species, IUCN
ASPCA Toxic and Non-Toxic Plant List, ASPCA

Notes and assumptions

Kew's specimen, brought from South Africa in 1775, is often called the oldest pot plant in the world (Palm House).
Vulnerable in the wild (IUCN); trade is CITES-listed.
Dioecious; "flowering" here means producing cones, which takes decades.

Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.

Related plants

Wood's cycad Encephalartos woodii
Cardboard palm Zamia furfuracea
Karoo cycad Encephalartos lehmannii
Burrawang (cycad) Macrozamia communis
Dwarf mountain pine Pinus mugo
Japanese maple Acer palmatum
Black walnut Juglans nigra
English yew Taxus baccata