Calla lilies (Zantedeschia) are admired for their elegant, trumpet-shaped flowers and attractive foliage. As tender perennials, their life cycle is deeply connected to the seasons and the specific climate in which they are planted. Their annual timeline is heavily dependent on regional weather patterns and the initial planting schedule. This guide clarifies the stages of the Calla Lily’s year, from planting to dormancy.
Setting the Stage: When to Plant Calla Lilies
The annual cycle for Calla Lilies begins with planting their rhizomes, which are fleshy, underground stems that store energy. In most climates, the general rule is to plant them in the spring, only after the danger of the last hard frost has completely passed. This timing ensures the sensitive rhizomes are not damaged by cold temperatures, which can prevent them from sprouting.
A minimum soil temperature is required for the rhizomes to successfully break dormancy and begin growth. Ideally, the ground temperature should be around 65°F (18°C) or warmer before planting outdoors. Planting the rhizomes 2 to 3 inches deep in well-draining soil provides the necessary warmth for initial development. Some gardeners pre-sprout their rhizomes indoors about four to eight weeks before the last frost to get a head start on the growing season.
Answering the Core Question: Emergence and Initial Growth
The time it takes for a Calla Lily to emerge—meaning the first shoots and leaves appear from the soil—is relatively quick once optimal planting conditions are met. Typically, the first signs of green growth appear within two to four weeks after the rhizome has been placed in the warm ground. This initial emergence marks the start of the plant’s active vegetative growth phase.
The speed of emergence is influenced primarily by the soil’s consistent warmth and adequate moisture levels. Planting in soil that is too cold will cause the rhizome to temporarily stop growing, delaying the appearance of shoots. Watering should be sparing immediately after planting until the initial leaves are visible. Too much moisture before the plant is actively growing can lead to the rhizome rotting. Once the first leaves are present, the plant grows quickly, requiring more frequent watering to fuel its development.
The Impact of Hardiness Zone on Timing
The annual timeline for Calla Lilies is significantly affected by the USDA Plant Hardiness Zone, which dictates whether the plant is treated as an annual or a perennial.
Colder Zones (3 through 7)
In colder zones, specifically USDA Zones 3 through 7, Calla Lilies are not winter-hardy and must be lifted from the ground in the fall for indoor storage. In these regions, the emergence time is entirely determined by the gardener’s decision to plant the rhizomes each spring. Planting must occur after the soil warms up past 65°F, resulting in a later start to the growing season compared to warmer climates.
Warmer Zones (8 through 10)
In warmer climates, such as USDA Zones 8 through 10, Calla Lilies are hardy enough to remain in the ground year-round as true perennials. Here, the plants experience a natural, earlier emergence in the spring, triggered by the soil temperature rising after their winter rest period. This perennial growth cycle means the plants emerge organically as the environment becomes favorable, rather than waiting for a specific planting date.
Completing the Cycle: Bloom Time and Dormancy
After initial emergence, Calla Lilies proceed through a period of rapid growth before entering their blooming phase. The flowering period typically begins about 60 to 90 days after the rhizome was planted or after the first shoots appeared. Plants planted in late spring generally produce blooms from mid-summer and often continue into early fall.
The active growing season concludes when the plant enters its natural dormancy period, signaled by a change in the foliage. As temperatures cool, usually in late fall or early winter, the leaves begin to turn yellow and eventually die back. This yellowing indicates that the plant is shifting energy and nutrients back into the underground rhizome for storage. Gardeners should gradually reduce watering at this point to encourage the plant to fully rest.
For those in colder zones, the rhizomes must be dug up and stored in a cool, dark location. This protects them from freezing temperatures below 50°F, completing the annual cycle until the next spring planting.