Growing Long-Day Onions in San Diego Fall

September planting works in frost-free San Diego. Start in flats until 6 inches tall, then transplant to well-drained sunny beds with ample water and organic fertilizer.

Keys to Success

• Long-day varieties need 14-16 hour days — San Diego summer days suffice
• Fall planting avoids spring bolting risk
• Consistent moisture critical for bulb formation
• Organic fertilizer supports steady growth

Your timing aligns well with Southern California's onion-growing window.