Calla Lily
Elegant funnel-shaped flowers in white, pink, purple, yellow, orange or near-black on arrow-shaped, often spotted leaves. Sold in bloom as a gift plant; it goes dormant afterwards and comes back from the rhizome if you let it rest. Toxic to pets.
Calla lilies are sold as flowering gift plants, and most are thrown away when the flowers finish. That is a waste, because the plant is a rhizome that flowers every year if you understand its cycle: grow, flower, die back, rest, repeat. The flowers are a single curled bract around a yellow spike, in white for the classic arum lily and in pink, purple, red, yellow, orange and near-black for the compact hybrids, on arrow-shaped leaves that are often flecked with white.
It is not a plant for year-round display. It is a plant for a spectacular six weeks, then a rest, then another spectacular six weeks. Treated that way, it is easy.
Light
Bright, indirect light with some direct sun while it is growing and flowering. An east window is ideal; a south or west one with the hottest hours filtered. The coloured hybrids need more light than the white arum lily. In dim light the stems stretch and the flowers fail.
Water
While it is growing and flowering, keep the soil evenly moist, watering every four days or so, and let it drain. The white arum lily tolerates wetter soil than the hybrids, which rot if soggy. When the flowers finish and the leaves start to yellow, cut watering right back, to once every three weeks or less, and let the plant die down. Resume when new shoots appear.
Soil and potting
A rich, well-draining potting mix with a third perlite. Pot with drainage. Repot the rhizome yearly when it is dormant, into fresh mix, an inch up if it has grown. Plant the rhizome two inches deep.
Feeding
Half-strength balanced feed every two weeks while growing and flowering. Nothing during dormancy.
Propagation
Divide the rhizome when dormant: cut it into sections with at least one growing point each, let the cuts dry for a day, and pot up. Flowers the following season.
In a hot, dry home
Manageable, with the cycle respected. It wants moist soil while growing, so check it every two or three days in a hot house, and a bright window that is not baking. Keep it away from vents while in flower. The dormant rest is easy in a warm house: put the dry pot in a cupboard for two months and forget it.
Calla Lily varieties
Same care, different look. These are the named forms you will see for sale.
- White (aethiopica)
The tall, classic white arum lily with plain green leaves. Prefers wetter soil and cooler rooms than the coloured hybrids.
- Pink
Compact hybrid with spotted leaves.
- Purple
Compact hybrid in deep violet.
- Dark Purple
Near-black flowers.
- Red
Compact hybrid in red.
- Yellow
Compact hybrid in gold.
- Orange
Compact hybrid in orange.
Problems and fixes
Leaves yellowing after flowering
Likely cause: Normal dormancy beginning
Fix: Reduce watering and let it die back; it returns in a couple of months.
Rhizome soft and smelly
Likely cause: Overwatering, especially during dormancy
Fix: Cut away rot, dust with cinnamon, repot dry.
No flowers the second year
Likely cause: No rest, or not enough light
Fix: Give it a two-month dry dormancy and a brighter window.
Stems flopping
Likely cause: Too little light
Fix: Move it to a brighter spot.
Calla Lily questions
Is calla lily safe for pets?
No. It contains calcium oxalate crystals that cause mouth irritation and drooling if chewed.
Will it flower again?
Yes, if you let it go dormant after flowering: dry it off for two months, then repot and water. It flowers about eight weeks after regrowth starts.
Why are the leaves dying?
After flowering, calla lilies die back naturally. It is not sick. Stop watering and let it rest.
