SproutSmart
SproutSmart Intelligent Garden Sowing

Red Marble · Onion

Zone 9a Save Garden

Planting Schedule

Add Red Marble to your garden to build a schedule and get reminders.
MilestoneDate
Start IndoorsJan 23rd
Last FrostMar 6th
Transplant / Direct Sow OutdoorsFeb 20th
Harvest BeginsMay 21st
Harvest EndsNov 26th

Crop Details

Transplant Conditions: Wait until soil reaches 45°F and nights stay above 35°F before moving outdoors. Harden off for 7 days first.
TraitValue
Days to Maturity90
Sun RequirementsFull 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
Expert Note: For cipollini-type onions, transplant when nights are consistently mild and keep the soil evenly moist so the bulbs form uniformly.