When growing calla lilies, plant them in the springtime. They grow moderately fast, often producing flowers by early-to-mid-summer and blooming throughout the season until early fall. Native to Africa, calla lilies grow in tropical climates but can sometimes be invasive, specifically in Australia and California. Calla lilies are toxic to humans and pets. All parts of the plant are toxic. They grow from a rhizome, not from a bulb, which is a key indicator that they’re not true lilies. Like other flowering plants, fertilizer encourages flower growth.
Light
True to their tropical nature, calla lilies thrive in a warm environment, including plenty of light. If you have hot and humid summer weather, your calla lilies might do better in a spot with partial shade. If you have a more temperate summer climate, your calla lilies can handle full sunlight.
Soil
A rich, moist, well-drained soil is best to keep calla lilies blooming. Calla lilies often do well growing alongside ponds and can happily tolerate a moist soil location. Although avoid allowing these plants to become waterlogged, as it can lead to root rot. To increase the nutritional density of your soil, amend it with organic matter before planting your flowers.
Water
Once the rhizomes are established, you can water the plants once a week or more frequently if experiencing especially hot or drought-like conditions. Calla lily plants potted indoors will need constant moisture, as pots will dry out sooner than ground plantings.
Temperature and Humidity
Calla lilies like a fairly warm environment and temperatures between 60 and 80 degrees Fahrenheit. They also enjoy a decent amount of humidity and moisture, so humid summers keep the flowers blooming just fine. When temperatures drop below 50 degrees Fahrenheit, the plants enter dormancy. Dig up your rhizomes for overwintering before freezing temperatures occur. Frost can kill the plant.
Fertilizer
Calla lilies need feeding upon planting and every spring at the beginning of the growing season to promote bountiful flowering. Most well-balanced fertilizers will work just fine. Avoid choosing a blend that is nitrogen-heavy; it can reduce the plant’s flowering.
Types of Calla Lily
Common calla lily flowers are white with a yellow spadix. These are often found listed as their botanical name Zantedeschia aethiopica. They are the hardiest of the calla lilies as well as the largest. Cultivars of this plant have been developed in different colors with a slightly smaller stature.
Zantedeschia ‘Edge of Night’: This plant’s flowers are dark purple to black in color, resembling black velvet.Zantedeschia ‘Red Alert’: This variety has bright orange and red flowers blooming from May through August.Zantedeschia ‘Picasso’: Features white flowers with a purple throatZantedeschia ‘Sunshine’: Features cheerful, bright yellow flowers
Pruning
Calla lilies don’t require regular pruning, but you can pull off wilted flower parts. Removing parts of this plant will not kill it. Pinch stems just below the base of the flower with your fingertips or use sterilized pruning shears. If you live in zone 8 or warmer, when it dies back at the end of the growing season, cut it down to the soil level and dispose of any plant debris. In the spring, it will return. (It is recommended to wear gloves when working with this plant to avoid touching the sap.)
Propagating Calla Lily
Calla lilies can be propagated by dividing their rhizome or rooting structure or growing the plant from seeds. Calla lilies form into large clumps, and you can divide the clumps into separate plants. Plants grown from rhizomes will flower much sooner than seed-grown plants. Here’s how to divide a calla lily rhizome for propagation:
How to Grow Calla Lily From Seed
It can take up to three years for a calla lily planted from seed to bloom. Calla lily seeds must be pre-grown, which can be done by spreading seeds out on a damp paper towel and covering them. Place the paper towel in a cool location, such as a basement or cellar. After a few days, check for growth. Discard any that do not show any signs of life. Put the seed in a high-quality soilless medium in a well-draining pot. Keep the soil moist and watch for growth. Watch the plants for a couple of weeks and remove the weakest shoot from each pot. You only want one seedling per pot.
Potting and Repotting Calla Lily
One indication that your calla lilies are ready for a bigger pot is when the roots start to look crowded. Root-bound calla lily plants will not thrive, so replant them if you notice an issue with their roots. Get a pot that is at least two or three inches deeper and wider than the old pot. To repot calla lilies, carefully lift the flowers out of their smaller pot and gently place them into the larger one, taking care not to damage the delicate roots. Fill the new pot with soil up. Keep the soil moist consistently for a few days after repotting. Make sure the soil is not soggy or waterlogged. Terracotta pots are a great option for this plant since the porous nature of the pot allows air and water to pass through its walls, promoting healthy plants by helping prevent overwatering. A downside to clay pots is soil dries out quicker, requiring more frequent watering.
Overwintering
If you live in a USDA hardiness zone cooler than 8, you can dig up and overwinter the rhizomes, or buy new rhizomes each growing season. Once you dig up a rhizome, gently brush off any remaining dirt. Do not wash or water the calla lily rhizomes since that can cause fungal root rot. Cut off the foliage from the top of the rhizomes. Allow the rhizomes to dry in a warm, dry, well-ventilated place for four to seven days. This is important to calla lily care in winter because it allows the outer skin of the rhizome to toughen up or cure. After the calla lily rhizomes have dried, place them in a paper bag or wrap them separately in newspaper. Store them in a cool, dry place: somewhere that stays around 50 degrees Fahrenheit. Usually, a garage or basement works well.
Common Pests and Diseases
You may have to contend with several issues when growing calla lilies, most notably bacterial soft rot, which affects the rhizomes, and botrytis, which is a fungal disease that causes a filmy grey mold to grow over the plant’s petals, stems, and leaves. To reduce the risk of fungal diseases, don’t overwater the plants, and make sure to plant your calla lilies far enough apart so that they have ample air circulation. Various pests can also be an issue for calla lilies, including insects like aphids, slugs, and spider mites. Treat the plants with a mild insecticidal soap or horticultural oil like neem oil to combat these issues.
Common Problems With Calla Lily
It’s generally easy to grow calla lilies. Other than regular water, they do not need much care. However, if their growing needs aren’t met, they can suffer.
Brown Edges of Leaves
If you notice a brown edge on the leaves, it may be a sign that your fertilizer has too much nitrogen in it. If your plant grows rapidly and looks lush but has brown-edged leaves, a nitrogen-rich fertilizer can cause that. Your plant will likely not bloom either.
Yellowing Leaves, Wilting, or Stunted Growth
Calla lilies are water lovers. If they are not getting enough water, they may not bloom, will look stunted, and leaves will appear yellowed and wilted. Water calla lilies consistently to keep your plant’s foliage healthy and encourage flowering; stunted growth can also be caused by lack of sunlight.
Drooping Stems and Flowers
Plant droop can be caused by too little and too much watering. Also, too much nitrogen in fertilizer can lead to drooping stems and flowers. If it doesn’t have enough water, adding water will help it perk up.
