Sow
0.98 inches (2.5 cm) deep with a guideline distance of
1.95 inches (5.0 cm). Soil temperature should be kept higher than
13°C / 55°F to ensure good germination.
By our calculations, you should look at sowing Rossa di Milano about 28 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Rossa di Milano is a hardy plant.
Presumably the name refers to it originating near or in Milan.