Grown Ailsa Craig Onion?

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Ailsa Craig Onion — Root vegetables

110days to harvest

10-15days to germinate

Z5–10USDA zones

Moderatedifficulty

Heirloom

Sowing

Start seeds indoors 10-12 weeks before last frost, or plant sets in early spring when soil is workable.

Cultivation

Sun: Full sun (6+ hours)
Water: 1-1.5 inches per week, reduce watering as bulbs mature
Soil: Rich, well-drained loam with high organic matter
Soil pH: 6.0-7.0
Spacing: 4-6 inches apart, rows 12-18 inches apart
Height: 12-18 inches
Season: Cool to warm season, long growing period

Appearance & flavour

Colour: Pale yellow to golden brown papery skin, white flesh
Size: 4-6 inches diameter, can reach 8+ inches
Shape: Large perfect globe, slightly flattened
Flavour: Surprisingly mild and sweet for such a large onion, with low sulfur content

In the kitchen

Excellent for fresh eating, cooking, caramelizing. Good storage onion. Perfect for stuffing due to size.

Pests, disease & resistance

Pests: Onion thrips, onion maggot, cutworms
Diseases: Downy mildew, purple blotch, neck rot, white rot
Resistance: Moderate resistance to downy mildew and neck rot

Planting calendar by USDA zone

Zone	Start indoors	Transplant	Direct sow	Harvest
1	—	—	June – July	September
2	—	—	May – July	September
3	—	—	May – June	August – October
4	—	—	April – June	August – October
5	—	—	April – May	August – November
6	—	—	April – May	July – November
7	—	—	March – May	July – November
8	—	—	March – April	June – December
9	—	—	February – March	May – December
10	—	—	January – March	May – December
11	—	—	January – February	April – December
12	—	—	January – February	April – December
13	—	—	January – February	April – December

Companion planting

8 beneficial pairings indexed for this variety, 3 to avoid.

CarrotsOnions repel carrot flies while carrots help break up soil for onion bulb development

TomatoesOnions deter tomato hornworms and aphids, while tomatoes don't compete for nutrients

LettuceShallow-rooted lettuce doesn't compete with onions and benefits from onion's pest-repelling properties

BrassicasOnions repel cabbage worms, flea beetles, and other brassica pests

PeppersOnions deter aphids and other soft-bodied insects that attack pepper plants

StrawberriesOnions repel slugs and other pests while improving strawberry flavor

MarigoldsBoth repel similar pests and marigolds add extra nematode control

ParsleyAttracts beneficial insects and doesn't compete for space or nutrients

Avoid

BeansOnions can inhibit bean growth and nitrogen fixation by rhizobia bacteria

PeasOnions stunt pea growth and interfere with their nitrogen-fixing capabilities

AsparagusBoth compete for similar soil nutrients and can inhibit each other's growth

Nutrition (per 100 g)

Calories (per 100 g): 40
Protein (g): 1.1
Fat (g): 0.1
Carbohydrate (g): 9.34
Fibre (g): 1.7
Sugars (g): 4.24
Vitamin A (µg): 0
Vitamin C (mg): 7.4
Vitamin E (mg): 0.02
Vitamin K (µg): 0.4
Vitamin B6 (mg): 0.12
Folate (µg): 19
Calcium (mg): 23
Iron (mg): 0.21
Magnesium (mg): 10
Phosphorus (mg): 29
Potassium (mg): 146
Zinc (mg): 0.17
Selenium (µg): 0.5

← PreviousBlack Spanish Round Radish Next →Touchon Carrot

Where to buy seed and equipment

Some links are affiliate links. If you buy through them we may earn a commission at no extra cost to you.

Growing it? There is a full cultivation guide at the root vegetables growing guide.

Cultivar facts compiled from public horticultural references including USDA GRIN and NC State Extension. Descriptions are original to this catalogue.

Sowing

Cultivation

Appearance & flavour

In the kitchen

Pests, disease & resistance

Planting calendar by USDA zone

Companion planting

Avoid

Nutrition (per 100 g)

Where to buy seed and equipment

Grown Ailsa Craig Onion?

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