SproutSmart
SproutSmart Intelligent Garden Sowing

Super Star

Onion

Planting Schedule

Add Super Star to your garden to build a schedule and get reminders.
Botanical illustration of Super Star
110d to harvest

Aromatically sweet at first touch, Super Star onions develop a mellow, golden depth with a crisp snap and a finely layered, tender bite. Their intermediate-day timing brings dependable bulbs to the garden in about 110 days, forming well-rounded shapes with a handsome, papery sheen that stores with confidence. Grow Super Star for bold flavor in everyday cooking, from roasting and sautéing to savory sauces and pickling brines—an all-purpose onion that stays vibrant from harvest through the season.

Crop Dates

Growing note: Zone 2a has only 96 frost-free days — shorter than this crop's 110-day maturity. Outdoor planting is not viable; use protected cultivation.
MilestoneDate
Last FrostMay 25th
Growing ApproachProtected Environment Only

Crop Details

TraitValue
Days to Maturity110
Sun RequirementsFull SunFull sun
Growth HabitBulbing
Support NeededNone
Planting DepthNormal
Germination Temp (°F)70
Min Soil Temp (°F)40
Min Night Temp (°F)28
Harden Off (days)7

Frequently Asked Questions


How do I prevent and treat onion (Allium cepa) downy mildew or purple blotch?
In onions (Allium cepa), downy mildew and purple blotch show as gray/whitish fuzzy patches or purple lesions on leaves, especially when nights are cool and foliage stays wet. Water at the base so leaves dry quickly, remove badly infected tops, and improve airflow by spacing bulbs properly. If problems start early, use a labeled onion fungicide and keep spraying on the label schedule until you see new growth staying clean.
When are super star onions ready to harvest, and how can I confirm it?
Harvest when about 50–70% of tops have fallen over and the remaining leaves are yellowing, typically around 110 days for this type of Allium cepa. Lift a few bulbs first to check: skins should feel papery and tight, and the bulb neck should be firm. Cure harvested onions in a warm, airy spot for 1–2 weeks until outer skins are fully dry, then trim roots and tops for storage.
Botanical illustration of Super Star

Aromatically sweet at first touch, Super Star onions develop a mellow, golden depth with a crisp snap and a finely layered, tender bite. Their intermediate-day timing brings dependable bulbs to the garden in about 110 days, forming well-rounded shapes with a handsome, papery sheen that stores with confidence. Grow Super Star for bold flavor in everyday cooking, from roasting and sautéing to savory sauces and pickling brines—an all-purpose onion that stays vibrant from harvest through the season.