Macrozamia Cycads: Australia's Majestic Large Landscape Species

Macrozamia—an exclusively Australian genus—offers some of the most ornamental cycads for landscapes and containers. This article covers the larger "Section Macrozamia" species; the smaller, twisted-leaf "Section Parazamia" will follow.

Unique among cycads, most Macrozamia produce leaves singly or continuously (not in periodic flushes). Mature plants hold dozens of leaves—far more than other genera—creating dense, semi-spherical clumps of deep green, plastic-like foliage, often mistaken for grass trees (Xanthorrhoea, Dasylirion). Leaflets are thin, flat, pointed, with a distinctive yellowish thickened base at the rachis. Some form massive clumps to 15 ft wide; a few develop palm-like trunks to 20+ ft (M. moorei). Most have subterranean caudexes; some eventually form short above-ground stems. Dioecious: deep green spiky cones—female wide, male narrow and tall.

Macrozamia communis with cones and continuous new leaves

M. moorei with 3–4 ft clear trunks (left); M. johnsonii caudex ~2.5 ft diameter (right)

Female cone (M. communis); M. moorei cone with ripening fruit; opening cone releasing fruit

Most prefer full sun; some suffer in shade. Generally cold-hardy to light frosts; some handle moderate freezes (few tolerate regular snow). Mealybugs can be problematic due to dense foliage limiting air circulation. Respond well to water and fertilizer; avoid overhead winter watering (rot risk).

Key Larger Species

Macrozamia communis: Common in NSW under eucalypts. Beautiful blue-green, stiff, sharp-tipped leaflets. To 6 ft tall × 10 ft wide. Slow seedling; eventually constant leaf production. Very cold-hardy; tolerates light snow. Thrives in hot, dry, full sun with water.

Large M. moorei in CA (left); wild (center, photo kennedyh); trunking botanical specimen (right)

Macrozamia diplomera: Smallest of the group; often forked leaflets (rare in cycads). Bluish-green leaves, upright or droopy. Excellent slow container/landscape plant. Needs sharp drainage—rot-prone. Cold-hardy.

Old potted specimen; botanical plant with few splits; typical split leaflets

Macrozamia dyeri: Most attractive of three WA species. Perfect shuttlecock of arching blue-green, stiff, pointed leaflets. Trunks eventually to 8+ ft. Slow, rot-prone when young if overwatered or poorly drained.

Maturing in SoCal (left, center); young seedling (right)

Macrozamia fraseri: Rare WA species, large, less symmetrical than dyeri, bright green, closely spaced leaflets. Orange wool at leaf bases on mature plants.

M. fraseri in CA; caudex fuzz

Macrozamia johnsonii: Massive—one of Australia's largest cycads. Trunks to 9+ ft tall, >2 ft thick. Holds 100+ leaves. Bright to yellow-green, flat in cross-section (vs. M. moorei's twisted V-section). Sharp but flexible leaf tips—less hazardous. Mealybug-prone due to dense crown.

Botanical specimen; flat leaf cross-section; young leaf bases with fuzz/yellow color

Macrozamia longispina: Personal favorite. Medium, elegant—thin, very long, flexible bright green leaflets. Upright leaves. Rare but increasing. Frost tolerance untested. Distinguished from similar M. miquelii, M. mountperriensis by even longer leaflets.

M. longispina for sale

Macrozamia lucida: Smaller, arching sparse crown, wide slightly falcate leaflets. Slow; needs protection from hot dry sun. Holds fewer leaves—less ornamental.

Private garden SoCal (left); female cones (right)

Macrozamia macdonnellii: Most sought-after, hardest to grow. Stunning blue-turquoise leaves in full sun (shade dulls color/health). Straight, stiff, lethally sharp leaflets. Desert-adapted; hates humidity. Cold- and heat-tolerant. Hates transplanting—plant permanently. Rare, pricey, over-collected, vulnerable.

In Hawaii (left); habitat (right, photo kennedyh)

CA specimens (left, center); mature leaf close-up (right)

Macrozamia miquelii: Medium, common, graceful mound of soft bright green arching leaves, long thin leaflets. One of 4–5 similar species (douglasii, macleayi, mountperriensis, longispina).

M. miquelii

M. macleayi and M. douglasii

M. mountperriensis

Macrozamia montana: Small-medium, upright leaves like dwarf M. communis. Uncommon; seedling happy in full sun (slow). Mountain NSW origin suggests good frost tolerance.

M. montana seedlings

Macrozamia moorei: Classic giant—tallest Macrozamia (20+ ft wild). Dark to blue-green, strongly arching V-section leaves, 100+ palm-like leaves. Slow seedlings; accelerate with age. Common in trade; transplants well.

Maturing SoCal (left); M. moorei (center); M. johnsonii (right)

M. moorei cone; seedling; mature plants awaiting planting in Thailand

Macrozamia riedlei: Most common/easiest WA species. Rarely trunks; smaller, lighter green, softer leaves. Best for paths/planters—less hazardous. Fast, easy; but I've rotted it with overhead winter watering.

SoCal nursery (left); my seedling (right)

Maturing in botanical gardens

Macrozamia spiralis: Misnamed—leaves rarely spiral. Constant confusion. Small (~2 ft), spreading, soft arching leaves (10–12 per plant). Harsh rocky NSW eucalypt habitat; freezes common. Conventional in cultivation but less ornamental. M. elegans similar, rarer.

M. spiralis in botanical garden (note lack of spiraling)