Native to South Africa, Calla Lilies deserve a spot in the garden or at home. Whether used in borders, containers or as cut flowers, they always provide a spectacular effect with their rich, cheerful colors and their breathtaking chalice-shaped flowers (spathe) surrounding a yellow finger-like stalk (spadix). And they are so easy to grow! With very little work needed, they will burst into bloom and add bright notes of summer color to the garden, or to your pots inside your home - provided some basic rules are respected.
1. Choose The Right Rhizomes (or Tubers)
- Choose rhizomes that are large, firm, and plump.
- The size of the rhizomes is highly correlated to the overall size of the plant and its blossoms. The bigger the rhizome, the bigger the plant and more spectacular the flowers.
2. Select The Right Site
- Calla Lilies grow in full sun or partial shade. Full sun is best in cool summer areas but part shade is preferred in hot summer areas.
- Calla Lilies perform best in organically rich, moist, well-drained soils. Consistent moisture is essential, but avoid overwatering to prevent rot.
- Choose a sheltered position and add some well-rotted organic matter before planting.
- Calla Lilies are well-suited for bog or marsh gardens, for planting near ponds and streams, as border plants or for containers.
- Some Calla Lilies (e.g. Zantedeschia aethiopica) can be grown in water up to 12 in. deep (30 cm). Use aquatic compost and a 12 in. deep (30 cm) planting basket.
- Calla Lilies are winter hardy in hardiness zones 8-10 - However, please note that hardiness varies among the species and cultivars. In cooler climates (zones 3-7), the tubers are planted in the spring, after the danger of frost has passed, and usually treated as annuals. However, if you want to save your bulbs for next spring, you may dig them up before the first frost and store them over winter before replanting them next spring. Not sure about your growing zone? Check here.
3. Planting Your Calla Lilies
- Calla rhizomes should be planted in spring. They may be started indoors as early as a month before the average last frost date (for earlier blooms) or planted directly in the ground after the danger of frost has passed. For early flowering plants at Easter, plant the rhizomes in December.
- If conditions are cool or soil temperature is cold, delay the planting until the soil has warmed to at least 65°F (18°C).
- Plant your calla rhizomes 4 in. deep (10 cm) and about 12 in. apart (30 cm).
- Set the calla rhizome with the growing tips facing up. Cover the rhizome with soil and water as needed. Mulch to keep down weeds and conserve soil moisture.
- After planting, it may take 2 weeks or more for the first shoots to appear. The rhizomes take about 13-16 weeks to start flowering depending upon the cultivar and planting date. When Calla Lilies are planted in the spring, they will produce flowers between midsummer and early fall for 3-8 weeks. Their flowering period depends on the temperature, amount of light and the variety. In climates where Calla Lilies are perennial, they typically bloom in late spring to early summer.
- Provide consistent moisture during the growing season and do not allow the soil to dry out.
- Feed with a balanced liquid fertiliser every two weeks until the flowers have faded.
- Mulch annually in fall with well rotted garden compost or manure.
- Remove the flower stems after the blooms have faded.
- Zantedeschia makes excellent cut flowers and have one of the longest vase life among cut flowers (up to 2 weeks).
- The flowers which are fully open (with their stamens visible) can be harvested. This should be done in the cool of the morning or evening. The flowers should be pulled rather than cut. Cutting dammages both flowers and tubers.
- Propagate by division, in spring. Small rhizomes that have been overwintered in pots under cover can be cut up into sections, each with a visible bud. Large overwintered clumps in the garden can be divided by lifting the plant before there is much top growth, and chopping through the roots with a spade and dividing into smaller sections.
- Most calla lilies are winter hardy in zones 8-10, so in these warm climates the rhizomes can be left right in the ground. If you live in a colder area and you want to save your rhizomes for next spring, you may dig them up before the first frost and store them over winter before replanting them next spring. Not sure about your growing zone? Check here.
- As soon as temperatures drop below freezing and the foliage turns brown, cut down the foliage and stems to about 1-2 in. (2-5 cm), and lift the rhizomes for winter storage. If you are growing different varieties of calla lilies, you should label them.
- Wash and dry the tubers. Let them cure for 2-3 days in a warm, dry place at temperature of 65-75°F (20-25°C). Then place them into a box with barely damp peat moss. Store the box in a dark place at 50-60°F (10-15°C).
- Check the rhizomes during the winter months to make sure they are not too moist or too dry.