Can You Plant Calla Lilies Outside? Zone Guide & Care Tips

By Rachel Green · February 15, 2025

Can You Plant Calla Lilies Outside?

Yes, you can plant calla lilies outside in USDA hardiness zones 8 to 10, where they thrive as perennials. In colder zones (7 and below), they can be grown as annuals or dug up and stored indoors over winter. Calla lilies prefer well-drained soil, partial to full sun, and consistent moisture for optimal growth and flowering.

Understanding Calla Lily Growing Zones

Calla lilies (Zantedeschia spp.) are native to southern Africa and grow best in warm climates. Their ability to survive outdoors year-round depends largely on the local climate and winter temperatures.

Key Factors for Outdoor Planting

Hardiness Zones: Perennial in zones 8–10; tender in zone 7 and below.
Frost Sensitivity: Rhizomes rot if exposed to prolonged freezing temperatures.
Soil Type: Prefer moist, well-drained, organically rich soil.
Sun Exposure: Perform best with 6+ hours of sunlight daily, especially in cooler zones.
Water Needs: Require consistent moisture but not waterlogged conditions.

Best Time to Plant Calla Lilies Outdoors

The ideal time to plant calla lily rhizomes outdoors is in spring, after the last frost date when soil temperatures reach at least 55°F (13°C). This ensures strong root development before summer heat.

Regional Planting Schedule

Zones 8–10: Plant in early spring; may bloom by late spring to summer.
Zones 4–7: Treat as annuals or start indoors 4–6 weeks before last frost.
Tropical Areas (e.g., Florida, Hawaii): Can be planted nearly year-round with proper irrigation.

USDA Zone	Average Minimum Temp (°F)	Outdoor Survival	Recommended Action	Bloom Season Duration
8	10 to 20°F	Limited survival; mulch heavily	Dig up or mulch 4–6 inches deep	8–10 weeks
9	20 to 30°F	Good survival with protection	Mulch base; reduce watering in winter	10–12 weeks
10	30 to 40°F	Excellent perennial performance	Plant and leave in ground	12–16 weeks
7	0 to 10°F	Poor survival without digging	Dig rhizomes before first frost	6–8 weeks (as annual)
6 and Below	Below 0°F	No outdoor winter survival	Grown as potted annuals only	6 weeks (container)

Table data source:USDA Plant Hardiness Zone Map, Royal Horticultural Society

The data shows a clear correlation between warmer zones and longer bloom periods. Gardeners in zones 9–10 enjoy the longest flowering season and lowest maintenance, while those in zones 7 and below must take proactive steps to preserve rhizomes. Mulching significantly improves winter survival in marginal zones.

Care Tips for Outdoor Calla Lilies

To ensure healthy growth and vibrant blooms, follow these care guidelines once planted outside.

Watering and Drainage

Calla lilies need consistently moist soil but are prone to root rot in soggy conditions. Water deeply 2–3 times per week during active growth, adjusting based on rainfall and temperature.

Fertilizing Schedule

Apply balanced fertilizer (10-10-10) at planting time.
Side-dress monthly during growing season (spring to early fall).
Stop fertilizing once foliage begins to yellow in fall.

Pest and Disease Management

Common issues include aphids, spider mites, and fungal rots. Prevent problems by spacing plants 12–18 inches apart for airflow and avoiding overhead watering.

Overwintering Calla Lilies in Cold Climates

If you live in zone 7 or lower, you’ll need to dig up calla lily rhizomes before the first hard frost (typically when temps drop below 25°F).

Step-by-Step Overwintering Guide

Cut back foliage after it dies down or following first frost.
Dig rhizomes carefully, avoiding cuts or bruises.
Cure them in a dry, shaded area for 2–3 days.
Store in peat moss or vermiculite in a cool (50–60°F), dark place.
Check monthly for rot or desiccation.

Frequently Asked Questions About Planting Calla Lilies Outside

Can calla lilies survive winter outdoors?

Only in USDA zones 8–10. In zones 8 and 9, heavy mulching improves survival. In zone 10, they typically survive and rebloom reliably. In colder zones, rhizomes must be dug up and stored indoors.

Do calla lilies come back every year?

Yes, in suitable climates (zones 8–10), calla lilies return annually as perennials. Elsewhere, they can be replanted each spring if properly stored over winter.

How deep should I plant calla lily rhizomes outside?

Plant rhizomes 2–4 inches deep, with the eyes (growing points) facing upward. In cooler zones, plant slightly shallower; in hotter zones, go deeper to retain moisture.

Can calla lilies grow in full sun?

Yes, especially in cooler climates. In hot southern regions, provide afternoon shade to prevent scorching. At least 6 hours of direct light is recommended for flowering.

What should I do if my outdoor calla lilies aren’t blooming?

Lack of blooms may result from too much nitrogen, insufficient sunlight, overcrowding, or cold stress. Use a low-nitrogen, high-phosphorus fertilizer, ensure 6+ hours of sun, and divide clumps every 2–3 years.