Potato Onions (Allium cepa var. aggregatum), also known as Hill Onions or Mother Onions, are a long-term storage multiplier onion that produces clusters of bulbs. With proper storage, they can last up to 12 months, making them a valuable addition to your garden. Here’s everything you need to know about planting, growing, and harvesting potato onions.
Click here to access the complete Potato Onion Growing Guide (PDF) for detailed information on soil preparation, planting, and long-term care.
Why Grow Potato Onions?
• Long-Term Storage: Can last up to 12 months under the right conditions.
• Larger than Shallots: Produces bigger bulbs with a stronger flavor.
• Cold-Hardy: Ideal for fall planting in mild to moderate climates.
• Multiplying Bulbs: Each bulb produces clusters, increasing your harvest year after year.
Best Growing Conditions for Potato Onions
Soil and Sun Requirements:
• Soil Type: Prefers well-drained, organic-rich soil with a mildly acidic to neutral pH.
• Sunlight: Full sun for maximum growth.
• Watering: Keep soil consistently moist, using drip irrigation to avoid rot.
• Fertilization: Use a 5-10-5 phosphorus-rich fertilizer after planting to promote bulb growth.
Companion Planting:
• Good Companions: Cabbage, carrots, leeks, lettuce, marjoram, parsley, parsnips, roses, and tomatoes.
• Avoid Planting Near: Beans and peas.
How to Plant and Grow Potato Onions
Planting Times:
• Fall Planting: Ideal for mild winters, from October to December. Bulbs will produce larger yields.
• Spring Planting: Best for regions with harsh winters. Plant when the ground is workable.
Planting Depth and Spacing:
• Small Bulbs: Space 4–6 inches apart.
• Large Bulbs: Space 8 inches apart.
• Row Spacing: 12–18 inches apart.
• Depth: Plant bulbs so that ½–1 inch of soil covers them. In colder climates, plant slightly deeper (up to 5 inches of soil covering).
Mulching:
• Fall Planting: Add 4–8 inches of mulch to protect from freezing. Remove most of the mulch in spring.
How to Harvest Potato Onions
When to Harvest:
• Harvest when tops fall over, signaling maturity.
• Stop watering 2 weeks before lifting to allow bulbs to cure.
Harvesting Technique:
• Collect the entire cluster or only a few bulbs for immediate use.
• Always harvest on a dry day to prevent rot.
How to Cure and Store Potato Onions
Curing:
• Cure for 1–2 months in a shaded, well-ventilated area.
• Spread bulbs in a single layer and check regularly for spoiled bulbs.
• After curing, trim tops to 1 inch above bulbs and separate clusters.
Storage Conditions:
• Temperature: Store between 35–40°F or 50–70°F with 60–70% humidity.
• Do Not Refrigerate: Onions may sprout if stored between 40–50°F.
• Storage Method: Use a mesh bag or a single-layer shelf with good air circulation in a root cellar or cool room.
• Shelf Life: Properly stored potato onions can last up to 12 months.
Common Pests and Diseases of Potato Onions
Pests:
• Onion Flies: More common in wet seasons. Use labeled insecticides.
• Onion Thrips: Control with insecticidal soap.
• Flea Beetles: Chew leaves; use sticky traps, row covers like Agribon, or organic insecticides.
• Slugs: Hand-pick or apply slug control products.
Diseases:
• Onion Rot: Prevent with proper crop rotation and well-drained soil.
• Mildew: Use drip irrigation to keep foliage dry and improve air circulation.
Pest Management with Integrated Pest Management (IPM):
• Cultural Controls: Remove plants immediately after harvest to reduce pest breeding grounds.
• Crop Rotation: Rotate onions every 3–5 years to prevent pest and disease buildup.
• Healthy Starts: Always plant disease-free bulbs.
🧅🌱 Resource Area: Mastering Potato Onions, Shallots, Leeks, and Egyptian Walking Onions
Dive deeper into growing and utilizing various allium varieties like potato onions, shallots, leeks, and Egyptian walking onions. These resources will help you with everything from planting tips to culinary uses and sustainable gardening practices.
- 📘 Potato Onion Growing Guide: Planting, Care, and Harvesting Tips
- Get a detailed guide to potato onion care, including the best growing conditions, planting methods, harvesting, curing, and storage. Perfect for gardeners looking to extend their harvest.
- 🎥 Growing Onions, Leeks, and Shallots - Video Guide
- Watch expert videos on growing onions, leeks, and shallots, covering essential tips for planting, care, and harvest in your garden.
- 🌿 Shallots and Leeks: The Lesser-Known Onion Cousins for Your Garden and Kitchen
- Discover the unique characteristics of shallots and leeks and how to incorporate them into your garden and kitchen. These flavorful, lesser-known alliums are worth the space!
- 🌱 Sustainable Gardening with Egyptian Walking Onions: A Perennial Powerhouse
- Learn about Egyptian walking onions—how to plant, grow, and sustain them in your garden. These perennial onions are hardy, low-maintenance, and packed with flavor.
- 🍽️ The Unique World of Egyptian Walking Onions: Benefits and Culinary Uses
- Explore the many culinary uses and health benefits of Egyptian walking onions, from the bulb to the green shoots, in your recipes.
- 🌾 A Comprehensive Guide to Growing Egyptian Walking Onions: From Planting to Harvest
- A detailed guide to planting, growing, and harvesting Egyptian walking onions. These resilient perennial onions will provide you with a continuous supply for years to come.
- 🧅 Egyptian Walking Onions: A Growing Guide
- Learn everything about Egyptian walking onions, including planting instructions, care tips, and harvesting guidelines to grow these unique, perennial alliums successfully.
- 🛒 Shop Onion Seeds & Sets
- Browse a selection of organic and heirloom onion seeds, including multiplier onions, potato onions, and Egyptian walking onions, to get started on your next garden project.
This Resource Area provides a great starting point for exploring the world of alliums, from practical planting advice to culinary inspiration and sustainable gardening techniques. Ready to grow your onion garden?
