If you enjoy growing plants and flowers from bulbs in your container garden, you will want to be sure to know the best way to store your bulbs over winter. In most climates, it is not a good idea to leave the bulbs in outdoor planters over cold winters. Temperature and moisture requirements for storage vary for each bulb species. If your climate is mild enough for particular bulbs, it is preferable to keep bulbs in the garden planter and cover them well before the winter starts. Agapanthus, Amaryllis belladonna, Crinum, Canna and Lily will have better blooms in each year if left in the soil and protected..
When grown in garden containers, it is usually best to keep the bulbs in the flower pot and place it under proper growing/storage conditions inside the home, garage or storage area.
Achimenes - Leave rhizomes in container, dry out planting medium, and place at 60-70°F (16-21°C).
Agapanthus - Two overwintering options are possible, depending on the variety:
Amaryllis belladonna - Store bulbs in container at 55-70°F (13-21°C).
Anemone coronaria (St. Brigid and De Caen) - Store tubers dry at 50-55°F (10-13°C). Leave them in planters and carefully cover for protection.
Begonia (Tuberous Hybrids) - Harvest the corms in fall, and store in dry peat at 35-41°F (2-5°C).
Canna - Harvest rhizomes in fall, and store in dry peat or vermiculite at 41- 50°F (5-10°C) or leave them in the planter and cover them up well.
Crinum - Store bulbs in slightly moist sand at 35-45°F (2-7°C). If grown indoors in a container, place in a bright, cool [55°F (13°C)] night temperature room.
Crocosmia (syn. Montbretia) - Store corms in peat or vermiculite at 35-41°F(2- 5°C), or leave them in the ground and cover them.
Dahlia - Harvest tuberous roots in fall, keep away from drafts, and store in vermiculite or dry sand at 35-45°F (2-7°C).
Eucomis - Store bulbs dry at 55-68°F (13-20°C).
Freesia - Store corms or containers dry at 77-86°F (25-30°C).
Galtonia - Store bulbs dry in vermiculite at 63-72°F (17-23°C).
Gladiolus - Harvest corms after foliage dies. Store dry in mesh bags 41 - 55 °F (5-13 °C).
Gladiolus Callianthus (syn. Acidanthera bicolor) - Harvest corms in the fall, dry, clean carefully, and store at 55-68°F (13-20°C).
Haemanthus - Bring containers indoors and either store dry or continue growing at 55-65°F (13-18°C).
Hymenocallis - Place container-grown plants indoors and grow them at 55- 65°F (13-18°C). To store unplanted bulbs, harvest them carefully leaving soil around the roots, and store dry at 60-70°F (16-21°C).
Ixia - Store corms dry at 68-77°F (20-25°C).
Liatris - Store corms in moist peat at 35°F (2°C).
Lilium - Better to leave in the ground, but can be stored in moist peat at 35°F (2°C).
Nerine - Store bulbs dry or in container with ventilation at 35°F (2°C).
Ornithogalum - Store bulbs dry at 70-80°F (21-27°C).
Oxalis - Store rhizomes or bulbs in peat or vermiculite at 35- 41°F (2-5°C).
Ranunculus - Store tuberous roots dry at 50-55°F (10-13°C).
Sandersonia aurantiaca - Store tubers in vermiculite at 63°F (13°C).
Schizostylis - If storing, place rhizomes in moist peat at 45°F (7°C). However, it is preferable to keep them in a protected planter or a container to perennialize.
Sparaxis - Store corms dry at 68-77°F (20-25°C).
Sprekelia - Store bulbs dry in peat or vermiculite at 41-55°F (5-13°C).
Tigridia - Store bulbs in peat or vermiculite at 35-41°F (2-5°C).
Veltheimia - If possible, do not store bulbs. If stored, keep dry at 77°F (25°C). When bulbs are in containers, take indoors for winter at 50-60°F (10-16°C). Blooms in February.
Zantedeschia (Calla Lilies) - Store rhizomes or tubers dry at 50-60°F (10- 16°C).