How to Grow and Care for Colored Calla Lilies, How Long They Live, and Are They Toxic or Easy to Grow?

Colored calla lily (Zantedeschia aethiopica) is native to South Africa. It is a perennial herb of the genus Zantedeschia in the Araceae family. The colored calla lilies grown as cut flowers mainly include red calla lily and * calla lily; their cultivation habits are fundamentally different from the common white calla lily, and cultivation is somewhat difficult. Under normal conditions, colored calla lilies can be grown for 3-4 years.

I. Selection and Treatment of Tubers

  1. Tuber selection: For tubers used to produce cut flowers, choose healthy, disease-free tubers with bright color and plump buds. The corm size should preferably be about 3-5 cm in diameter; tubers that are too small bloom little or not at all.

  2. Variety selection: Tubers should be selected from varieties with strong disease resistance, vivid flower color, flower color not sensitive to light changes, high cut flower yield, and a relatively large market share.

  3. Pre-planting treatment of tubers: Treating colored calla lily tubers with gibberellin can promote flowering and increase cut flower yield. Generally, before planting, soak them in a gibberellin solution at a concentration of 25-50 mg/kg for 10-15 minutes; if the time is too long or the concentration is too high, it easily causes deformed flowers.

  Selection of cultivation environment: Colored calla lily prefers a warm, humid, shady environment and is not cold-tolerant. The suitable temperature during the growing period is 15 to -24°C during the day, and the night temperature should not be lower than 12°C; high temperatures above 30°C easily cause outbreaks of soft rot. The cultivation environment should remain well ventilated and appropriately shaded. The cultivation site should preferably be sandy soil with higher terrain, good drainage, rich organic matter, and a pH of around 7, with nitrogen, phosphorus, potassium, and a large amount of decomposed organic fertilizer applied.

II. Planting Tubers

  1. Planting time should be determined according to the needs for cut flowers and tubers. However, colored calla lily planted in spring has the highest cut flower quality and yield; for forced and delayed cultivation, attention must be paid to flower-inducing treatment of the tubers and effective control of the cultivation environment to succeed profitably. Before sowing, sprout the tubers, and plant after new shoots begin to sprout.

  2. Planting depth: Generally, tubers 3-4 cm in size are planted at a depth of 10 cm; for tubers larger than 5 cm, a depth of 15 cm is suitable. After planting, water thoroughly, cover the ground with wheat straw to increase humidity and lower soil temperature, and promote tuber sprouting and rooting.

  Water and fertilizer management: Water management during the growing period of colored calla lily is very important. In general, it should be moist in the early growth stage. After flowering, water should be appropriately controlled; during the tuber-building period after flowering, a dry environment is suitable to plump the tubers and force dormancy.

  When sufficient base fertilizer is applied, only appropriate topdressing is needed. Usually before flowering, use 1000x calcium nitrate for foliar spraying 2 times, with an interval of 7 days, to promote flowering; after flowering, apply compound fertilizer to promote tuber plumpness and maturity.

Are colored calla lilies toxic? Calla lily itself is toxic, containing large amounts of raphides and alkaloids; accidental ingestion can cause symptoms such as lethargy and poisoning. This species is a toxic plant included in the Chinese plant atlas database, and its toxic parts are the tuber, spathe, and spadix. Chewing a small piece of the tuber can cause swelling and pain of the tongue and throat.