Onion plants need the right amount of sunlight in order for the plant to develop a bulb and grow properly. Whether you’re growing short day, intermediate day, or long day cultivars, if the plants don’t get the sunlight they need, you’re not going to have a good harvest. So keep these rough guidelines in mind as you plan your planting:
Short day varieties
- Need 10 hours of sunlight a day
- USDA Hardiness Zones 7 and up
Intermediate day varieties
- Also called day neutral
- Need 12 to 14 hours of sunlight a day
- Zones 5 and 6 (most of the U.S. Midwest)
Long day varieties
- Need 14 to 16 hours of sunlight
- Zone 6 and colder
It’s not just the zone you’re in—it’s where your garden is, too. Check the sun pattern where you plan to plant your onions. Is there an extended period of shade during the day? Talk with your local garden shop about the best varieties to grow in your specific gardening area.
How do you ensure that your onions get the right amount of sunlight? Do you have tips for getting your onions planted in the right spot for proper amounts of sun and shade? Please tell us how you handle sunlight for your onions.