Walla Walla Sweet Onions are famous open-pollinated, heirloom, onions that are ultra large and very sweet. They have a slightly flattened round shape with light brown skin and creamy white flesh and have upright tops that dry down well. First brought to Washington from the island of Corsica in the 1900s this onion has been carefully selected for size and sweetness. Germination temperature: 75-85 deg. in 10 days. Optimal pH: 6.2-6.8 Approximately 6,500 seeds/oz., 230 seeds/ 1 gm pkt.
Planting and Care: Onions started from seeds store better than sets but mature later. Directly sow the seed into well-drained fertile soil with lots of added organic matter in full sun in northern areas or partial shade in hotter climates. In the Northwest, the seed is sown in late August for harvest early next summer. In areas with colder winters seed may be sown early spring. Start indoors in late winter 10-12 weeks before planting time for short growing seasons. Onions begin to bulb when the day has 12-14 hours of daylight so southern areas may not get enough daylight to bulb. When seedlings reach 5“ trim to 1” to increase girth.
Harvest: Pull for fresh eating whenever they reach the desired size. When growing for storage, pull whenever the tops dry up and flop over. Pull and allow to cure for 3-5 days on the top of the soil or inside at 75-80 degrees F and 80% humidity. Cool slowly and store at steady temperatures. Optimal storage is at near freezing temperatures and 65-70% humidity.
Your Health: Onions are an excellent source of vitamin C, B6, Folate, manganese, sulphuric compounds, flavonoids and phytochemicals.
Light Partial/Full sun
Seed Depth 1/8-1/4 ” / 3-6 mm
Seed Spacing 1/2” / 12 mm
Row Spacing 18-30” / 30-76 cm
Days to Sprout 10
Plant Spacing 4” / 10cm
Days to Maturity 100-120
Plant your Walla Walla Sweet Onions with strawberries, the onion helps the berries fight disease. Keep your onions away from peas and asparagus!