Grown Walla Walla Sweet Onion?

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Walla Walla Sweet Onion — Onions & alliums

125-140days to harvest

10-15days to germinate

Z5–10USDA zones

Moderatedifficulty

HeirloomContainer friendly

Sowing

Start seeds indoors 10-12 weeks before last frost. Transplant when soil can be worked in spring. Can also plant sets in early spring.

Cultivation

Sun: Full sun (6+ hours)
Water: 1 inch per week, consistent moisture
Soil: Well-drained, fertile soil with high organic matter
Soil pH: 6.0-7.0
Spacing: 4-6 inches
Height: 12-18 inches
Season: Warm season annual

Appearance & flavour

Colour: Golden yellow exterior with white flesh
Size: 4-6 inches diameter, 8-16 oz
Shape: Large, flattened globe shape
Flavour: Exceptionally sweet and mild with low sulfur content

In the kitchen

Fresh eating, salads, grilling, roasting, caramelizing. Not suitable for long-term storage.

Pests, disease & resistance

Pests: Onion thrips, onion maggots, cutworms
Diseases: Pink root, fusarium basal rot, downy mildew, purple blotch
Resistance: Moderate resistance to pink root and fusarium basal rot

Planting calendar by USDA zone

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

CabbageOnions repel cabbage worms, cabbage loopers, and other brassica pests

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

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

StrawberriesOnions repel slugs, aphids, and other strawberry pests while not competing for space

RosesOnions repel aphids, black spot fungus, and other rose pests when planted nearby

BroccoliOnions deter cabbage moths and flea beetles that commonly damage brassicas

Avoid

BeansOnions can inhibit bean growth and nitrogen fixation, reducing bean yields

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

AsparagusOnions can inhibit asparagus spear development and overall plant vigor

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

← PreviousRed Burgundy Shallot Next →Red Wing Storage Onion

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 onions & alliums 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 Walla Walla Sweet Onion?

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