Storage Onion Seeds

West Coast Seeds, Storage Onion Seeds - Additional Information

How to Grow Onions

Planting:
Begin sowing storage onion and shallot seeds indoors during late winter to early spring, ready for transplanting 2-4 weeks after the last frost. For onions meant to overwinter, start in early summer for an August transplant. Direct sow scallions post-frost every 3 weeks until late summer, aiming for a soil temperature of 21-25°C (70-75°F) for optimal germination. Seeds typically sprout within 6-12 days.


Seed Starting:
For home gardeners, starting transplants is highly recommended. Place 3 seeds 5mm-1cm (¼-½”) deep in each cell of a 72-cell tray. When transplanting, maintain clumps 15cm (6") apart in rows spaced 45-75cm (18-30") apart. Scallions can be planted closer, at 2-5cm (1-2") apart, in rows 15cm (6") apart.


Growing:
Storage onions thrive in a pH of 5.5-6.5, requiring fertile, well-drained soil and full sun. Enrich the soil with compost and a balanced organic fertilizer for each 3m (10’) row. Ensure consistent moisture in the soil's top layer without burying bulbs too deeply. The size of the bulb correlates directly to the size of its foliage. Use frost protection for late scallion plantings.


Harvesting:
bulbs on their sides for a week before lifting. Curing in a ventilated, shaded area is critical for longevity. Post-curing, store in a cool, dry place in mesh sacks or braids. Regular inspection is vital to removing any compromised bulbs. Properly cured onions will last until the late spring.

Onion Pests & Diseases

Botrytis Blast:
To prevent Botrytis blast, a fungal disease that affects scallions, ensure good air circulation around your plants by spacing them properly and avoiding overcrowded conditions.

Implement a crop rotation strategy to avoid planting alliums in the same spot year after year, as this can reduce the build-up of fungal spores in the soil. Water the base of the plants early in the day, giving them time to dry before evening, to keep the foliage as dry as possible. If you detect the disease, remove and destroy affected plants to prevent its spread.

For organic control, apply a copper-based fungicide as a preventive measure during humid or wet conditions, following label directions closely.


Downy Mildew:
Downy mildew, another fungal issue, thrives in cool, wet conditions. To fend off this disease:

1. Water your scallions in the morning so the plants have time to dry throughout the day.
2. Ensure proper spacing between your scallions to improve airflow and reduce humidity levels around the plants.

Use organic fungicides and follow the instructions carefully to prevent the disease from spreading. Keep the garden clean by removing plant debris after the growing season to reduce the risk of downy mildew.