100days to harvest
7-14days to germinate
Z5–10USDA zones
Easy to moderatedifficulty
HeirloomContainer friendly

Sowing

Start from seed indoors 10-12 weeks before last frost, or direct sow in fall in warm climates.

Cultivation

Sun
Full sun (6+ hours)
Water
1 inch per week, consistent moisture
Soil
Well-drained, fertile loam with good organic content
Soil pH
6.0-7.0
Spacing
4-6 inches
Height
12-18 inches
Season
Cool season

Appearance & flavour

Colour
Deep red-purple skin with white flesh and purple rings
Size
3-4 inches diameter, medium size
Shape
Round to slightly flattened globe
Flavour
Mild, sweet, and crisp with less bite than yellow onions

In the kitchen

Excellent fresh in salads, sandwiches, and salsas. Good for quick cooking but shorter storage life.

Pests, disease & resistance

Pests
Onion thrips, aphids, wireworms
Diseases
Fusarium basal rot, bacterial soft rot, downy mildew
Resistance
Moderate disease resistance

Planting calendar by USDA zone

ZoneStart indoorsTransplantDirect sowHarvest
1——June – JulySeptember
2——May – JulyAugust – September
3——May – JuneAugust – October
4——April – JuneAugust – October
5——April – MayJuly – November
6——April – MayJuly – November
7——March – MayJune – November
8——March – AprilJune – December
9——February – MarchMay – December
10——January – MarchApril – December
11——January – FebruaryMarch – December
12——January – FebruaryMarch – December
13——January – FebruaryMarch – December

Companion planting

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

TomatoesAlliums repel aphids and spider mites that commonly attack tomatoes
CarrotsOnions deter carrot flies while carrots help break up soil for bulb development
LettuceAlliums repel aphids and rabbits that damage lettuce crops
BrassicasOnions deter cabbage worms, flea beetles, and aphids from cabbage family plants
RosesAlliums repel aphids, thrips, and may reduce black spot fungal issues
PeppersOnions deter aphids and may improve pepper flavor and growth
StrawberriesAlliums repel slugs and aphids while potentially improving berry flavor
MarigoldsBoth repel nematodes and create a pest-deterrent barrier when planted together

Avoid

BeansAlliums can inhibit nitrogen fixation by rhizobia bacteria in legume roots
PeasOnions release compounds that stunt pea growth and reduce pod production
AsparagusAllelopathic compounds from onions can reduce asparagus spear production

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

Where to buy seed and equipment

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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.

DarkGrow forum

Grown Rossa di Milano?

Post a crop report — day counts, reservoir readings, what worked. Variety-specific logs are the most useful thing on the forum.

Similar varieties

Other alliums with a comparable time to harvest, so a season that suits Rossa di Milano suits these too.

Browse all 44 alliums