Ailsa Craig Onion Plants
Best choice for northern gardeners seeking massive, sweet, and storable onions.
Discover the Ailsa Craig Onion, an English heirloom renowned for its impressive size and exceptional sweetness. These onions can grow to a substantial 2 pounds with a 6-8 inch diameter, boasting a firm texture and straw-yellow globe. As a long-day variety, they are ideal for northern climates and offer a longer storage life than many sweet Spanish types. Perfect for salads and burgers, these plants are shipped hardened-off and ready for your garden. They thrive in light, sandy, loamy soil with consistent watering.
$22.95
Owner Satisfaction
4.6
/ 5
Category Rank
832
/ 2996
#832 in Landscaping & Garden Plants
Price vs Category Average
-17%
Below average
Days to Maturity
105
/ days
Who it's for
- Busy growers wanting to skip the hassle of starting seeds
- Competitive gardeners aiming for massive, exhibition-quality harvests
- Home cooks seeking mild, versatile onions for fresh recipes
Who should skip it
- Southern gardeners living in short-day growing regions
- Homesteaders needing onions that last through the entire winter
- Beginners struggling with inconsistent garden temperatures or transplant stress
Performance breakdown
Yield Potential
Capable of producing massive two-pound bulbs with consistent care.
Flavor Profile
Exceptional sweetness makes these a standout choice for fresh culinary use.
Storage Longevity
Outperforms most sweet varieties in shelf life after the harvest.
Climate Adaptability
Specifically optimized for northern regions with long-day growing cycles.
Planting Readiness
Hardened-off starts minimize transplant shock for immediate garden integration.
Growth Consistency
Requires specific soil conditions to reach full size and firm texture.
Key Specs
Days to Maturity
105 days
Bulb Size
6–8 inches
Weight
up to 2 pounds
Seed Depth
⅛–½"
Soil pH Preference
6.0-7.0
Mature Height
0.5 feet
Mature Spread
8 feet
Sun Exposure
Full Sun
Features
- Prized English heirloom variety
- Exceptionally sweet and firm
- Large straw-yellow globe onions
- Longer storage capability
- Ideal for northern growing regions
- Open-pollinated for seed saving
- Shipped hardened-off and ready to plant
What customers say
Customers consistently praise the exceptional quality of the Ailsa Craig onion starts, noting they arrive healthy and robust, ready for immediate planting. The primary sentiment revolves around reliability; these plants establish easily and reliably produce large, sweet onions, making them a favorite for gardeners seeking a dependable harvest. The ease of transplanting and the impressive final yield underscore the product's strong value, confirming that the initial investment translates directly into a successful and abundant crop.
Know before you buy
Ailsa Craig is a long-day variety, meaning it is specifically bred to bulb in northern regions where daylight hours are longer during the summer. While they can grow in zones 3-10, they will perform best in northern latitudes.
Under ideal conditions, these onions can reach a diameter of 6 to 8 inches and weigh up to 2 pounds. Consistent watering and well-draining, nutrient-rich soil are key to achieving this size.
No, the plants are shipped already hardened-off. They are ready to be transplanted into your garden as soon as they arrive and weather conditions permit.
Ailsa Craig onions offer a longer storage life than many other sweet onion varieties. For the best results, cure them in a cool, dry, and well-ventilated area after harvest.
They thrive in light, sandy, or loamy soil with a pH between 6.0 and 7.0. Ensuring your soil is loose and well-draining will help the bulbs expand to their full potential.
Yes, because this is an open-pollinated heirloom variety, you can successfully save the seeds from your harvest to replant in future seasons.
Still have a question?
Ask Hayley anything about this product before you decide.
Ready to buy?
$23