Growing Calla Lilies from Seed and Overwintering Corms in Pennsylvania

Calla lilies (Zantedeschia) are not hardy in Pennsylvania (zones 5–6). To save them, you must lift corms or grow from seed.

Overwintering Corms (Recommended)

1. After first frost kills foliage, dig corms.
2. Shake off soil—do not wash.
3. Air-dry 1–2 weeks in shade.
4. Store in peat/vermiculite in mesh bags at 45–55°F.
5. Replant spring after soil >60°F.

Growing from Seed (Advanced)

1. Collect seed pods when brown and splitting.
2. Sow immediately 1" deep in moist potting mix.
3. Keep warm (70–75°F) under lights.
4. Germination in 30 days.
5. Feed seedlings at 3" tall with ½-strength fertilizer.
6. Transplant to individual pots.
7. Grow under lights until frost-free.

Key Tips

• Fresh seed germinates best.
• Seed-grown plants take 2–3 years to bloom.
• Corms are faster and true to type.

For most home gardeners, lifting and storing corms is the reliable method.