Why Plants Die
Theme

Sago palm

Cycas revoluta, Cycadaceae

Sources last read 14 September 2026.

Forgiving Among the more tolerant plants here.

Also called cycad, Fern Palm, Japanese Sago Palm and King Sago Palm.

Sago palm (Cycas revoluta), the whole plant.
Agnieszka Kwiecień, Nova, CC BY-SA 4.0 · Wikimedia Commons

Sago palm is toxic

  • Toxic to cats. Toxic principle: Cycasin. Clinical signs: Vomiting, melena, icterus, increased thirst, hemorrhagic gastroenteritis, bruising, coagulopathy, liver damage, liver failure, death. ASPCA
  • Toxic to dogs. Toxic principle: Cycasin. Clinical signs: Vomiting, melena, icterus, increased thirst, hemorrhagic gastroenteritis, bruising, coagulopathy, liver damage, liver failure, death. ASPCA
  • Toxic to people. Harmful when eaten; irritates skin. Use gloves and protective gear when handling it. RHS

What the sources say about its care

Sources file this plant under other names: Cycas revoluta, zamia species (ASPCA). Citations below point at the name its source uses.

Light
Partial shade
RHS · read 13 September 2026
Water
Moist but well-drained
RHS · read 13 September 2026
Humidity

No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.

ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%
Penn State Extension · read 13 September 2026
Temperature

How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.

H3 — -5 to 1°C -5 to 1 °C
RHS · read 13 September 2026
Soil
Loam; pH Acid or Neutral
RHS · read 13 September 2026
Toxic to cats
Toxic
ASPCA, filed as Cycas revoluta, zamia species · read 13 September 2026
Toxic to dogs
Toxic
ASPCA, filed as Cycas revoluta, zamia species · read 13 September 2026
Harmful to people
Harmful when eaten; irritates skin. Use gloves and protective gear when handling it.
RHS · read 13 September 2026

How it usually goes wrong

Dry, curled edges on fronds near a heater

A yellow halo sits just inside the brown edge on the sago palm, and new fronds often come in already tipped with brown during the heating season.

The edges fail first because they are the end of the plumbing. Penn State Extension cites 30% to 60% as the recommended indoor range, and winter heating regularly takes a room under it. That applies while it is grown indoors; its RHS rating of H3 describes a plant that also grows outside, where the air is seldom that dry.

Telling it apart: Whether the soil is dry too. Crisp edges with damp soil point at the air; with dry soil, at the watering.

Penn State ExtensionSago palm brown leaf tips and edges: causes
New fronds are smaller than the old and further apart

The sago palm looks sparse rather than sick: fewer fronds, spaced further apart, all angled toward the window.

Its source puts it in partial shade. Under that, each new frond costs more than it returns, so the plant builds fewer and thinner ones.

Telling it apart: Whether old growth is affected. Light shows in what arrives next; feeding shows in what is already there.

RHSDiagnose leggy growth on this Sago palm
Split, browned fronds on the side of the plant facing the wind

After a windy night the sago palm shows fresh brown edges and a few torn fronds, all facing the same way.

Its source lists a sheltered position. Wind strips moisture from the fronds and knocks them together, and a plant that is not suited to exposure shows both kinds of damage.

Telling it apart: The pattern of the damage. Tears and bruises point at wind; soft, spreading patches point at rot or disease.

RHSSago palm brown leaf tips and edges: causes
Yellowing that begins at the lowest fronds

Colour goes before shape on a sago palm. The lowest fronds yellow evenly, stay soft to the touch, and the compost two inches down is still wet from the last watering.

Its source describes soil that is moist but well-drained. Roots held below that are short of air, and roots short of air stop moving water, so the plant wilts in a wet pot.

Telling it apart: Whether new growth is affected too. Root damage shows up everywhere at once; ordinary leaf loss shows only in the oldest leaves.

RHSDiagnose yellowing leaves on this Sago palm

Not sure which it is? Ask the diagnosis questions for Sago palm.

Routine care

Watering
In the growing season water moderately; at other times water sparingly.
RHS · read 13 September 2026
Propagation
Seeds or suckers can be used for propagation.
NC State Extension · read 13 September 2026
Increase from seed or suckers.
RHS · read 13 September 2026
Pruning
Dead fronds can be cut away.
NC State Extension · read 13 September 2026
Pruning is not needed.
RHS · read 13 September 2026
Pests and diseases
Usually free of pests outdoors; under glass, glasshouse red spider mite can occur. Diseases: usually none.
RHS · read 13 September 2026

Move something and watch

Loading the simulator. It needs JavaScript; the care table above does not.

About the plant

Cycas revoluta is a species of gymnosperm in the family Cycadaceae, native to southern Japan including the Ryukyu Islands. It is one of several species used for the production of sago, as well as an ornamental plant. The sago cycad can be distinguished by a thick coat of fibers on its trunk. The sago cycad is sometimes mistakenly thought to be a palm, although the only similarity between the two is that they look similar and both produce seeds.

From Wikipedia, CC BY-SA 4.0 · read 13 September 2026

Native range
China (Fujian), Japan (S. Shikoku, Kyushu) to E. Taiwan
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Japan (Kyushu) to Nansei-Shoto
NC State Extension · read 13 September 2026
Far East
RHS · read 13 September 2026
Climate
subtropical
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Growth form
shrub
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Perennial, Shrub, Tree; habit erect
NC State Extension · read 13 September 2026
Tufted (evergreen)
RHS · read 13 September 2026
Size
Height 36–120 in; width 36–120 in
NC State Extension · read 13 September 2026
Height 1-1.5 metres; spread 1-1.5 metres after 20–50 years
RHS · read 13 September 2026
Flowering
Does not flower. Plants are either male or female, and seed needs both: males bear oval, yellowish pollen cones, females bear rounded cones that set seed once pollinated. Grown indoors as a houseplant, it seldom forms cones.
NC State Extension · read 13 September 2026
Flowers brown in summer; yellow in summer
RHS · read 13 September 2026
Uses

What sources record people using this plant for. A traditional or medicinal use listed here is a record of use, not advice to eat it or treat anything with it.

The pith holds edible starch that can be made into sago, but it needs careful washing to remove the pith's toxins.
NC State Extension · read 13 September 2026

Common problems with Sago palm

Plants with similar care

Sources

What this does not cover

The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.

Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.

If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.