Calla lily (Zantedeschia aethiopica 'White Giant')

Overview

The dramatic Zantedeschia aethiopica ‘White Giant’, commonly known as the Calla lily, is highly valued for its imposing stature, often reaching heights up to seven feet in ideal conditions. This rhizomatous perennial brings bold, vertical structure and large, elegant white spathes to any landscape, making it a show-stopping addition. While native to varied habitats in southern Africa, it thrives in moist or wet soils in gardens hardiness zones 8 through 10.

This specific cultivar, Zantedeschia aethiopica ‘White Giant’, features large, satiny white blooms surmounting stalks held well above its speckled green foliage. Beyond its use as a magnificent accent plant in the garden border, the Calla lily is prized commercially for its long vase life, making it a favorite for cut flower arrangements. Its cultural needs lean toward consistently moist conditions, even tolerating immersion in shallow water.

Gardeners seeking year-round interest can successfully grow this impressive plant in containers, allowing them to be moved to sheltered locations or indoors during colder winters. Considering its medium maintenance and water demands, the Zantedeschia aethiopica ‘White Giant’ rewards attentive care with spectacular summer blooms and architectural presence.

Fast Facts

• Plant Family: Araceae
• Plant Type: Herbaceous perennial
• Hardiness Zones: USDA Zones 8-10
• Size at Maturity:
  • Height: 4-7 ft
  • Spread: 3-4 ft
• Bloom Time: June to July
• Bloom Description: White spathe with yellow spadix
• Sun Exposure: Full sun to part shade
• Water Needs: Medium to wet
• Maintenance Level: Medium

How to Grow

Plant rhizomes of Zantedeschia aethiopica ‘White Giant’ in the spring only after all danger of frost has passed. Ensure they are planted approximately 3 to 4 inches deep and spaced 12 to 18 inches apart to accommodate their large mature spread. The Calla lily requires consistently moist ground; while it prefers full sun, providing some part shade will benefit the foliage, especially in hotter climates.

Watering is crucial for this species, aptly named due to its requirement for medium to wet conditions. In water feature settings, Calla lilies can be successfully planted directly into the mud at the edges of ponds, submerged up to 12 inches deep. For gardeners in borderline Zone 7, providing winter protection for the rhizomes or lifting them entirely is necessary to ensure survival.

In autumn, gardeners must decide whether to lift the rhizomes for storage in a damp medium, like peat, or transition them indoors. If overwintering in containers, place them near a bright window offering indirect light to keep them looking attractive as houseplants until spring planting resumes.

Landscape Uses

The substantial size and dramatic blooms of the Zantedeschia aethiopica ‘White Giant’ make it ideal for specific landscape roles. It excels when used as a bold specimen plant in borders, drawing the eye upward with its height of up to seven feet. For those designing water gardens or rain gardens, this plant fits perfectly along pond peripheries, thriving right at the water line.

Containers are another excellent application, allowing for repositioning based on seasonal light or protection needs. When grown in pots, the Calla lily forms a lush, tropical focal point for patios and decks. Consider pairing it with finer textured, moisture-loving plants like ferns or shorter, contrasting foliage for maximum visual impact.

Standout Features

Flower Qualities

• Showy
• Good Cut

Noteworthy Characteristics

Zantedeschia aethiopica, commonly called Calla lily, is a rhizomatous perennial native to southern Africa where it can be found growing in a wide variety of habitats including coastal marshes, montane grasslands, and old homesteads. The showy flowers consist of a yellow spadix surrounded by a bright white, funnel-shaped spathe that can reach around nine inches long. The selection ‘White Giant’ is particularly impressive, with green foliage speckled with white, allowing plants to reach up to 7’ tall in warmer climates.

Tolerances

• Wet Soil

Potential Problems

The primary concern for established Calla lilies is rhizome rot, which occurs when soil is persistently waterlogged and poorly draining outside of intended water garden settings. Management involves ensuring adequate soil aeration or improving drainage before planting. Additionally, Japanese beetles are noted pests that may feed destructively on the flowers and foliage during their active season, requiring manual removal or targeted treatment.

Frequently Asked Questions

What hardiness zones is Zantedeschia aethiopica ‘White Giant’ suitable for?

This Calla lily selection is winter hardy primarily in USDA Zones 8 through 10.

How large does Calla lily grow?

The Zantedeschia aethiopica ‘White Giant’ typically reaches a height of 4 to 7 feet and spreads 3 to 4 feet wide.

When does Zantedeschia aethiopica ‘White Giant’ bloom?

This plant generally produces its striking blooms between June and July, featuring a brilliant white spathe surrounding a yellow spadix.

What sun exposure does Calla lily need?

It performs best when given full sun to part shade exposure, though preference leans towards part shade in very hot regions.

Conclusion

The Calla lily, specifically the magnificent Zantedeschia aethiopica ‘White Giant’, offers unmatched seasonal vertical drama thanks to its height and stately white blooms. Its adaptable nature allows it to thrive in boggy areas, pond edges, or standard moist garden beds. Before planting, verify that your local USDA Zone falls within 8 to 10, or be prepared to provide necessary winter protection for this tropical beauty.

Companion Planting

When integrating Zantedeschia aethiopica ‘White Giant’ into a perennial border, select companions that enjoy similar high-moisture levels. Water-loving foliage plants such as Iris sibirica or tall ornamental grasses provide excellent textural contrast to the Calla lily’s broad leaves. For continuous moisture retention alongside pond peripheries, consider planting moisture-loving groundcovers that help suppress weeds while keeping the soil cool around the rhizomes.

Seasonal Care Calendar

Spring is the active planting season for this Calla lily, ensuring rhizomes are set after the last frost. Summer requires consistent monitoring of water needs to maintain the medium to wet soil levels it prefers during its active growth and bloom period in June and July. Late autumn dictates the most critical care: either lift the rhizomes if winter temperatures frequently drop below Zone 8 norms or ensure containers are moved indoors before the first hard frost threatens the clump.