Callas (Calla) – The Complete Guide

With colorful funnel flowers, callas create an exotic ambience on the windowsill and in the garden.

Their African origin, the different flowering times, and unorthodox facets of their cultivation raise questions about the calla lily. We will answer all your questions here in a compact and practical way.

Planting Callas Correctly

Plant summer-flowering callas in pots with loose substrate in February to advance them for the coming season. Place a calla bulb no more than 2-4 inches (5-7 cm) deep in the soil and water only sips at a time.

Until mid-May, gradually increase the amount of watering and fertilize every 14 days. In early June, plant the flowers in a sunny bed or the tub on the balcony.

Make sure that the top points straight upwards and that the calla lily is not deeper than 4 inches (7 cm) in the ground.

Care Tips

Their care is out of the ordinary in some respects. But that doesn’t mean callas are difficult to grow.

Use the following tips to care for your callas, and these exotic plants will give you plenty of pleasure:

  • Water callas regularly and abundantly while they are in bloom.
  • Fertilize them every 2 weeks from the beginning of sprouting until flowering, and every week during flowering.
  • At the end of the flowering period, stop fertilizing and gradually discontinue watering.
  • Repot winter-flowering calla lilies in late summer, and summer-flowering plants in spring.

Callas spend the dormant period, which usually lasts 10 weeks, in a cool, bright place. Houseplants can linger in the pot, while the flower tubers in the bed are dug up and stored in a dry, frost-free place.

Which Location is Suitable for Callas?

A light-filled location suits the sunny disposition of a calla lily. However, the flowers do not like to be confronted with the blazing midday sun.

The plant appreciates warm temperatures around 68 °F (20 °C) in summer, while hot spells can affect the flowering. During the dormant period, it may be cooler, but free of frost.

Callas make these demands on the soil:

  • Nutrient-rich, humus and fresh-moist.
  • In the tub, a compost-based potting soil with a handful of sand.

When is Flowering Time?

The flowering time for callas depends on the chosen variety. There are callas that bloom indoor from January to April and callas that decorate the garden from June to October.

Pruning Callas Properly

Extensive pruning is not necessary on callas. Cut off wilted and withered areas regularly to prevent rot from forming.

Watering Callas

Water your callas regularly and abundantly during the blooming season. The root ball of this plant should never dry out during the growing season.

After flowering, discontinue the water supply as the flowers enter a dry resting period. This applies both to indoor callas and summer-flowering callas in the garden.

Fertilizing Callas Properly

The nutrient supply of a calla lily is carried out in three stages.

During the dormant stage, do not fertilize your callas. With the onset of growth, administer a fertilizer for flowering plants every 14 days. Shorten the fertilizing rhythm during flowering to 8 days.

Are Callas Hardy?

The vast majority of callas plants are not hardy. Only a new cultivar of the section Zantedeschia aethiopica is able to withstand frosty temperatures with adequate winter protection.

Native to the warm regions of South Africa, the plant was not forced to adapt to frosty temperatures. Ingenious breeders have now succeeded in creating the first calla lily that can spend the winter in the garden.

The variety Crowsborough, which blooms white from June to August, does not need to be put away, provided that it receives adequate winter protection.

Wintering Callas

The majority of calla lilies are among the non-hardy flowers, so they spend the cold season frost-free. Usage, flowering time and species define the proper wintering of a calla lily.

Here’s how to do it right:

  • Allow summer-flowering callas to dry out in the fall and remove them from the soil.
  • Remove all leaves and remaining soil.
  • Store them in a bright, cool and especially dry place.
  • In February, plant them in pots with fresh substrate and place them in a warmer place.
  • From the middle of May, replant them in the bed or the tub.

For indoor callas, the growing season begins in early fall. Assign the flowers a bright location at temperatures of 54-59 °F (12-15 °C) and water them occasionally until the flowering period begins in January.

Wintering Callas in a Pot

Summer-flowering callas can be overwintered both without and in soil. Here’s how to overwinter them in a pot:

  • Stop watering and fertilizing following flowering.
  • Cut off all withered parts of the plant.
  • Move the callas in the pot to a cool, bright location.
  • From January, place the flowers in a warmer location and repot them in February.

Propagating Callas

Like all bulb flowers, calla lilies also develop breeding bulbs. These are excellent for straightforward propagation.

Use the annual repotting to cut off the daughter bulbs with a sharp knife. Planted in loose potting soil, they will develop into gorgeous blooming callas within a short time.

Seed sowing, on the other hand, is much more laborious and lengthy.

Repotting Callas

Repotting every year maintains the vitality and flowering of a calla lily. The ideal time for repotting is at the end of the dormant period, since at this time the stress factor for the plant is minimal.

Callas in a Pot

The calla lily is predestined for cultivation in a pot. Here it unfolds its exotic elegance in a sunny location either from January to April or during the summer.

Water the plant regularly during flowering and fertilize weekly with a liquid fertilizer. When the flowering season draws to a close, stop both the water and nutrient supply.

Until the next season, store the bulbs with or without soil in a dry, airy and bright place.

Is Calla Poisonous?

The classification of callas in the Araceae family signals that it is a poisonous plant. In fact, all parts of the plant contain toxic pungents.

These can cause skin irritation on contact and nausea and vomiting when eaten in large quantities. It is therefore not recommended to cultivate cally lilies in close proximity to children and pets.

Is the Calla Poisonous to Cats?

A calla lily poses a risk of poisoning for cats. This Araceae plant contains toxic pungents in its flowers, leaves and bulbs that cause cramps, vomiting and diarrhea when eaten.

Why Does My Calla Not Bloom?

If your calla lily does not bloom, you need to do some research to find the cause.

Check the site conditions as well as the water and nutrient balance. If the plant comes from a propagation by sowing, it will take several years until the first flowering.

Why Does My Calla Have Yellow Leaves?

If the leaves turn yellow after flowering, this is a natural process.

If the yellowing occurs prematurely, check the location, substrate, and water and nutrient supply. As a rule, this pattern of damage is due to errors in care.

The Calla Varieties

If you can’t get enough of elegant callas, combine the charming varieties that capable breeders have coaxed from the various species.

Zantedeschia aethiopica served as the mother plant for numerous indoor callas, which delight us on the windowsill from January to April with their tropical colors.

African species such as the Golden Calla (Zantedeschia elliottiana) and the Pink Calla (Zantedeschia rehmannii) produced magnificent flowers that bloom in the garden from June to October.

Some other beautiful cally lilies are:

  • Sensation: White and purple marbled calla lily with long flowering period from July to October.
  • Black Star: Captivates in the room and garden with dramatically colored funnel flowers in black from June to September.
  • Mango: A charming plant with orange blossoms for the summer flower bed, balcony and windowsill.
  • Mozart: A flower composition by master hand for a summer bloom in bright orange.
  • Pasja: Beautiful eye-catcher in pot and bed with violet iridescent flowers from June to August.
  • Green Goddess: Rare winter-flowering indoor calla with white-green bracts.

The Calla As a Houseplant

In order for the calla to remain favorable to you as a houseplant, no component of its cultivation should be neglected. The plant attaches great importance to this:

  • Sunny, warm location on the south or west window.
  • Constant moist during the flowering period.
  • Spraying every few days with lime-free water.
  • Fertilize every 14 days during growth, weekly during bloom.

At the end of the blooming period, gradually reduce the water supply and stop fertilizing. Once the leaves have yellowed, do not water at all.

Only in early fall, with the onset of growth, gradually resume watering a calla lily.

Calla Bulbs

The most beautiful callas thrive from bulbs. Plant these in pots with permeable substrate in the spring to sprout them.

Starting in May, set the plant in your choice of bed, large tub or planter box. A winter-flowering calla lily serves as a decorative indoor plant when the bulbs are planted in pots in early fall.

The Leaves of the Calla

If the leaves of a calla turn yellow prematurely, there is usually a failure to care for them. Also, check the foliage meticulously for infestation by pests, such as aphids, spider mites or mealybugs.

The Flower of the Calla

What we admire as a flower on a calla lily is actually a colorful coma. It has the task of attracting busy insects to pollinate the actual flower of this plant. This is located in the center of the coma in the form of a yellowish, green or brown cob.

The Calla Shines in Many Colors

You can see the need for care of a calla lily based on its color. A white-flowered calla lily is naturally more robust than flowers in bright colors.

So it is not a surprise that the only hardy plant of this genus blooms in bright white.

The Calla As a Cut Flower

A calla lily also works quite wonderfully as a cut flower. Water the plant copiously at the night before cutting.

The next morning, cut the flower stalks as low as possible and fix the end with some scotch tape to prevent it from curling up. The flowers will keep for up to 3 weeks in fresh water.

Calla Seeds

Only experienced gardeners with a lot of patience should grow callas from seeds. Sown in disinfected growing soil, germination takes weeks or even months at 68-72 °F (20-22 °C).

Keep the sowing constantly moist in a semi-shaded location. After you separate the seedlings in pricking out soil, the callas-to-be will go through the same wet-dry rhythm as an adult plant.

Beware that several years will pass before the first flowering.