Plant calla lily rhizomes outdoors in spring after your last frost, once days stay above about 70°F (Clemson). In colder areas, get a head start by potting them indoors 6 to 8 weeks before your last frost (Iowa State). Set rhizomes 3 to 4 inches deep (Clemson) and 12 to 18 inches apart (Clemson, NC State). Expect flowers about 60 to 90 days after planting (Clemson). Callas are toxic to pets if chewed (ASPCA).
Calla lilies (Zantedeschia) aren't true lilies. UMN says they are aroids, related to jack-in-the-pulpit and caladium, and Clemson notes they grow from rhizomes native to South Africa. Garden centers sell two main kinds. The tall white calla (Z. aethiopica) is the hardier one: NC State rates it to zone 8, or zone 7 with protection. The colorful hybrids in pink, yellow, orange and near-black are tender, and the RHS says most won't survive below 41°F (5°C).
When to plant calla lilies by region
| Area | When to plant calla rhizomes |
|---|---|
| Zones 3 to 7 (most of the North and Midwest) | Start rhizomes in pots 6 to 8 weeks before your average last frost, then plant out after frost (Iowa State). Dig before hard frost and store indoors (UMN) |
| Zone 7 | The white calla (Z. aethiopica) can survive with protection (NC State); colored hybrids are still best lifted |
| Zones 8 to 10 (the South, coastal West) | Plant in spring after frost once daytime temperatures stay above 70°F (Clemson). Callas can stay in the ground; mulch in zone 8 (NC State, Clemson) |
| Pots, any zone | Pot up in late winter or early spring indoors (UMN, RHS), and harden off before moving outside (RHS) |
Callas need warm soil, so there's no gain in planting early outdoors. Our planting calendar shows your average last spring frost; count back 6 to 8 weeks for the indoor start and plant out a week or two after the frost date once nights are warm (GardenPal suggestion).
How deep and far apart to plant calla lilies
| Calla lily rhizomes | |
|---|---|
| Depth | No deeper than 3 to 4 in (Clemson); 4 to 6 in (UMN); a 4-in hole for white callas (NC State). In pots, 1 to 2 in deep (Iowa State) |
| Position | Growing points (eyes) up; in pots the RHS leaves the top just showing |
| Spacing | 12 to 18 in (Clemson, NC State); 1 to 2 ft (UMN); about 12 in for tender hybrids (RHS) |
| Soil | Moist, rich and well-drained (Clemson, UMN); white callas tolerate wet soil (UMN, NC State) |
| Sun | Full sun gives the most flowers in Minnesota (UMN); morning sun and afternoon shade in hot South Carolina (Clemson); Iowa State lists part sun to part shade |
Starting indoors, watering and feeding
- Indoor start: pot rhizomes 1 to 2 inches deep in well-drained mix 6 to 8 weeks before last frost (Iowa State). Keep them warm and bright, and water sparingly until shoots appear, usually in a couple of weeks (RHS).
- Harden off potted callas for several days before planting out (RHS).
- Water: keep the soil evenly moist through the growing season (Iowa State), without letting it stay waterlogged (Clemson).
- Feed: UMN uses 5-10-5 or 5-10-10 in spring after planting. The RHS suggests a balanced liquid fertilizer every two weeks while they flower on poorer soils.
- Bloom time: about 60 to 90 days after planting (Clemson); July and August in Minnesota (UMN).
Calla lilies in containers
Compact colored hybrids are popular pot plants. Pots let northern gardeners start early indoors (Iowa State, UMN) and bring the plants in before frost. Use a free-draining mix and a pot with drainage holes, since the RHS warns that roots rot if overwatered while dormant. Gift callas bought in bloom can be planted out after frost or kept in their pots (GardenPal note).
Winter care: dig or leave in the ground
- Cold areas: callas aren't hardy in Minnesota, so UMN digs them and stores them indoors. The RHS brings tender hybrids inside for winter.
- Storage: let the rhizomes dry, then keep them dry at 50 to 60°F (NC State). The RHS waters only sparingly in winter, otherwise the roots may rot.
- Mild areas: Clemson lists callas as hardy in zones 8 to 10, and NC State overwinters them in zone 8 under mulch.
- Crowded clumps: the RHS lifts and divides them in early spring.
Pests, rot and pet safety
Clemson says voles and squirrels dig up and eat the rhizomes, and Japanese beetles, slugs and snails chew the leaves and flowers. The good news from Clemson: callas are deer resistant. Rot is the most common problem in heavy, wet soil (Clemson). For safety, the ASPCA lists calla lilies as toxic to dogs and cats because of insoluble calcium oxalate crystals, which cause mouth irritation, drooling and vomiting, and NC State rates the plant as highly toxic if eaten. Wear gloves if the sap bothers your skin (GardenPal suggestion), keep pets and small children from chewing the plant, and call a doctor, poison control or a veterinarian if any is eaten.
Calla lilies around the vegetable garden
Callas work as a summer flower in beds and pots near the vegetable garden, and white callas suit a soggy corner or rain garden where vegetables struggle (NC State). Plant them with other summer bloomers set out after frost; see when to plant dahlias, when to plant gladiolus and when to plant lilies.
Frequently asked questions
When should I plant calla lily bulbs?
Outdoors in spring after the last frost, once days stay above about 70°F (Clemson). You can pot them indoors 6 to 8 weeks before your last frost for earlier flowers (Iowa State).
How deep do you plant calla lilies?
No deeper than 3 to 4 inches (Clemson); UMN uses 4 to 6 inches. In pots, 1 to 2 inches deep (Iowa State).
How far apart should calla lilies be planted?
12 to 18 inches apart (Clemson, NC State); UMN allows 1 to 2 feet.
How long do calla lilies take to bloom?
About 60 to 90 days after planting (Clemson). In Minnesota they bloom in July and August (UMN).
Do calla lilies come back every year?
In zones 8 to 10 they can stay in the ground (Clemson). In colder areas, dig the rhizomes in fall and store them dry at 50 to 60°F (NC State, UMN).
Are calla lilies poisonous to pets?
Yes. The ASPCA lists them as toxic to dogs and cats because of calcium oxalate crystals that irritate the mouth. Call a veterinarian if a pet chews one.
Enter your frost dates to see your last spring frost and time your calla lily planting.
Open itSources
- Virginia Cooperative Extension, "Companion Planting in Gardening" (SPES-620P)
- University of Maryland Extension, "Vegetable Succession and Companion Planting"
- Oregon State University Extension, "Companion Planting"
- Penn State Extension, "Herbs Make Good Plant Partners and Companions"
- University of Minnesota Extension, "Planting the vegetable garden"
- USDA Plant Hardiness Zone Map
- NOAA NCEI U.S. Climate Normals (frost/freeze data)
- Clemson Cooperative Extension HGIC, "Calla lily"
- Iowa State University Extension, "Planting and caring for tender perennials"
- University of Minnesota Extension, "Calla and canna lilies"
- Royal Horticultural Society, "Calla lilies (Zantedeschia): growing guide"
- NC State Extension Gardener Plant Toolbox, "Zantedeschia"
- NC State Extension Gardener Plant Toolbox, "Zantedeschia aethiopica"
- ASPCA Animal Poison Control, "Calla lily"
Pairings are summarized in our own words from extension-service guidance. Research support for many companion effects is limited, so treat them as good habits, not guarantees.