Zantedeschia elliottiana aka Golden Arum Lily

Zantedeschia elliottiana is known as golden calla or Elliott’s calla. It belongs to the arum family, not the lily family. Kew places its native range in Mpumalanga, South Africa. RHS also gives its range as northern South Africa. Missouri Botanical Garden notes some doubt about its origin. It suggests the plant may have come from gardens. This tender perennial grows from underground tuberous rhizomes.

Plants reach about 2–3 feet [0.61–0.91 metres] in height. Missouri Botanical Garden gives a spread of 2 feet [0.61 metres]. RHS gives a smaller spread, up to 1.6 feet [0.5 metres]. The plant has no above-ground stem bearing its leaves. Its dark green leaves have an arrow shape and fine white spots. The leaves die back at the end of the season. Leafless flower stalks rise above this clump of foliage.

Flowers appear from July to September. Each flower head has a yellow spadix within a yellow spathe. The showy spathe reaches about 0.5 feet [0.15 metres] long. It provides much of the flower head’s bold colour. The plant suits borders, summer beds, and pots. It also works near ponds, pools, and small streams. These waterside settings still need soil that drains well. RHS lists courtyard, coastal, and cottage gardens among its uses.

Give it rich soil that stays moist but drains well. Missouri Botanical Garden favours sandy loam with added organic matter. RHS accepts several soil types and lists neutral pH. Full sun suits places with cool summers. Some shade helps where summers grow hot. Avoid excess watering, which can lead to soft rot. It can stay outdoors in USDA zones 9–10. RHS rates it H1C for UK conditions. In colder areas, lift the tubers before autumn frost. Store them somewhere cool and frost-free until spring.

Divide plants in spring, or raise them from seed. Seedlings may take two or three years to flower. Remove spent flowers and cut back leaves as they yellow. Watch for aphids, thrips, mites, whitefly, slugs, and snails. Japanese beetles may eat the leaves and flowers. Rust, fungal rots, bacterial rots, and viruses can cause trouble. The plant harms people and pets if eaten. It can also irritate skin and eyes. Wear gloves and protect your eyes when handling it.