Zantedeschia elliottiana

Common Name: golden calla 
Type: Bulb
Family: Araceae
Native Range: South Africa
Zone: 9 to 10
Height: 2.00 to 3.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: July to September
Bloom Description: Yellow
Sun: Full sun
Water: Medium
Maintenance: Medium
Suggested Use: Annual
Flower: Showy

Culture

Best growth outdoors occurs in consistently moist, fertile, organically rich, well-drained sandy loams in full sun to part shade. Consistent moisture is essential, but avoid overwatering which often leads to soft rot. Plants tolerate full sun in cool summer locations but prefer part shade in hot summer areas. Propagate by division in spring or seed. Seed grown plants may not flower for two to three years.

Plants may be grown outdoors year round in USDA Zones 9-10. North of Zone 9, container plants and/or dug tubers must be brought indoors prior to first fall frost for overwintering.

North of Zone 9, plant tubers indoors in pots several weeks prior to the last expected spring frost date. Place pots in a sunny window in consistently moist soil until the threat of spring frost is over, at which point the plants can be taken outside for planting in the ground or in large containers. Space at least 12” apart. Consistent moisture plus regular fertilization are important from spring until flowering ceases.

Stop fertilization and significantly reduce watering after bloom is completed (late summer to early fall) to allow soils to dry and plant growth to slow.

Overwintering options include: (1) For tubers growing in the ground, dig tubers and cut off remaining growth prior to first autumn frost, place tubers in sun for several days to dry out, and then bring tubers indoors for winter storage in peat or vermiculite at temperatures of 50-55 degrees F. (2) For tubers in containers, keep plants in containers year round, with watering being significantly reduced after flowers bloom. After the foliage dies back, containers should be brought indoors in fall prior to frost for overwintering of the dormant plants. (3) Grow as annuals.

Noteworthy Characteristics

Zantedeschia elliottiana, commonly called golden calla lily or Elliott’s calla, is a stemless herbaceous perennial of the arum family whose flowers and leaves rise to 2-3’ tall from underground tuberous rhizomes. It is reportedly native to South Africa, but may be of garden origin. Notwithstanding its common name, this species is a member of the arum family not the lily family. It is not even closely related to the lily family. Flowers bloom throughout summer (July – September). Each flower structure (to 6” tall) features a yellow finger-like spadix surrounded by a showy yellow spathe born atop a leafless stalk. Flowers resemble jack-in-the-pulpit. The very tiny and ornamentally insignificant true flowers of this plant are located on the spadix (males on top and females below). Flowers are infrequently followed by a spike of yellow berries. Long-stalked, arrowhead-shaped, dark green leaves (to 11” long) are heavily spotted with white.

Genus name honors Giovanni Zantedeschi (1773-1846), Italian botanist.

Specific epithet honors Captain George Elliott of Farnsboro Park, Hampshire at whose estate seed obtained from South Africa for this plant was first grown in 1886.

Problems

Susceptible to soft rot with erwinia bacteria, particularly in overly moist soils. Rust may develop on stems, leaves and spent flowers. Watch for slugs and snails. Japanese beetles may feed on the flowers/foliage.

Uses

Effective near ponds, pools or small streams, borders or in containers. Where not winter hardy, tubers must be be brought indoors in fall for overwintering.