SproutSmart
SproutSmart Intelligent Garden Sowing

Red Marble

Family: Amaryllidaceae Vegetable

Planting Schedule

Add Red Marble to your garden to build a schedule and get reminders.

Aromas of sweet earth and gentle bite rise from each jewel-like bulb—Red Marble delivers compact, perfectly round cipollini onions with a glossy, garnet-red skin that peels back to reveal crisp, pale rose interiors.

The texture is satisfyingly firm yet tender, with a balanced flavor that sweetens beautifully when roasted and shines in fresh preparations, as well as in sauces and quick pickles. For gardeners who love precision, this 90-day variety rewards careful spacing with uniform “marbles” that look as good as they taste.

Light: Full SunMaturity: 90 DaysHabit: Bulbing

Botanical illustration of Red Marble

Planting schedules and alerts are optimized for Columbus (Zone 6b).

Crop Dates

MilestoneDate
Start IndoorsMar 14th
Last FrostApr 25th
Transplant / Sow OutdoorsApr 11th
Harvest BeginsJul 10th
Harvest EndsOct 16th

Crop Details

TraitValue
Days to Maturity90
Sun RequirementsFull SunFull sun
Growth HabitBulbing
Support NeededNone
Planting DepthNormal
Germination Temp (°F)65
Min Soil Temp (°F)45
Min Night Temp (°F)35
Harden Off (days)7

Culinary Notes


Chef's Note

These compact cipollini-style onions behave like a best-of-both worlds onion: firm enough to stay crisp in quick pickles, but they melt into a candied, burnished sweetness when roasted. They’re especially good when you want that gentle bite to turn glossy and syrupy without disappearing entirely.

Best Uses

  • thin slicing for quick pickles that stay snappy
  • roasting until bronzed and jammy for a spoonable side
  • sautéing to glossy sweetness for pan sauces
  • serving raw in salads where bite can be controlled by salt/marinade

Flavor Profile

gentle, sweet-on-the-front onion bite crisp-tender snap with a juicy interior roast-sweet caramel tendencies a clean, bright aromatic finish

Kitchen Pairings

balsamic vinegar thyme goat cheese butter brown sugar beef or lamb

Frequently Asked Questions


What pest or disease issue commonly affects Allium cepa (red cipollini-type onions), and how can I manage it?
Onions (Allium cepa) commonly suffer from onion thrips, which cause silvery streaks and distorted, dried leaf tips. Spray plants with insecticidal soap and repeat every 5–7 days until new growth is normal, and remove heavily damaged leaves to reduce thrips habitat. Also watch for purple blotch/leaf blight (dark lesions that spread on leaves); keep foliage dry by watering at the soil line and improve airflow between plants.
How often should I water Allium cepa during the main growing phase to form good bulbs?
During bulb formation (roughly mid-season until leaves start yellowing), keep the top 2–3 in (5–8 cm) of soil evenly moist but not waterlogged. Water about 1–2 times per week with deep soakings, adjusting so you don’t see standing water and the soil still crumbles when squeezed. Once bulbing is underway, avoid letting the soil completely dry out for long stretches, since irregular moisture can lead to smaller bulbs and uneven maturity.
How do I know when Allium cepa (Red Marble-type onions) is ready to harvest?
Harvest when about 50–70% of the tops have fallen over and the remaining leaves are yellowing, typically around 90 days from planting. Gently lift one bulb to check size—bulbs should feel fully formed and the neck should be tight rather than soft. Stop watering a week before harvest so skins cure better, then cure in a dry, airy spot out of direct sun until outer skins are papery.