Rossa di Milano Onion
An excellent, heirloom Italian storage onion. Its name meaning "Rose of Milan," this onion sports purple-y red skins, a round shape and flat bottom, and purportedly stores well all winter long when cured properly. Its flavor is described as sweet, fragrant, and delicate yet strong. Our friends at Experimental Farm Network even report noticing a strong resistance to purple blotch disease with this variety, compared to other heirloom and hybrid onions.
Days to maturity: 100
Seeds per pack: 175
Germination rate: 99% on 12/31/2021
Planting / harvesting notes
Onions require full sun and well drained soil. Add plenty of compost or a raised bed for heavy soils. Direct sow in as soon as the soil can be worked in early spring (April/May in many places), and spread seeds in a 2" wide band, about 2 seeds/inch and 1/4" deep with rows 12–18" apart. Thin seedlings to about 2" apart (or 3-4" apart for larger onions).
Alternatively, in shorter season areas, sow seeds indoors in late February to mid-March. Spread seeds 1/2" apart and cover 1/4". Transplant to the garden 4" apart. Harvest when necks become soft and tops flop over. Cure in the sun for 2-7 days, and finish curing somewhere more protected from the elements.
Seed keeping notes
Onions are biennials, and go to flower and seed in their second year only. Separate onions of different varieties by 800 feet to 1/2 a mile. To preserve the genetic diversity of your onion population, save seeds from at least 5 plants, but 20-50 plants is even better. Allow the flower heads to dry on the plant and the seeds to develop. Harvest the seed head when the seeds just start to fall on their own and place them upside-down in a paper bag. Many seeds will fall in the process of collecting the seed heads this way. Rough up the seed heads to remove the seeds and sift out the seeds from the chaff with a strainer or screen. Winnow gently with your breath, the wind, or a fan, and store seeds in a well-labeled, air-tight, screw top jar in a cool, dark place such as a basement or closet.