Sterling Onion

$4.99

Sterling Onion is a hybrid, long-day variety with colossal, globe-shaped, white bulbs. Strong, vigorous tops protect bulbs from sun damage as they mature. Allium cepa. 95 days to maturity.

250 seeds per packet

Availability: In stock

Sterling Onion is a hybrid, long-day onion variety that produces jumbo to colossal onions with a shiny, white exterior. This white onion variety is globe-shaped with a mildly pungent onion flavor. The plants are vigorous and produce strong, tall tops to protect the onion bulbs from sun damage as they mature. Sterling Onion has mid to long-term storage potential and is a great option for gardeners and small-scale farmers in long-day growing areas.

Sterling Onion can be direct-seeded or transplanted, although we recommend transplanting. For direct-seeding, plant seeds 2″ apart along the row with a row spacing of 24″. Once seedlings emerge, thin seedlings to a 6″ plant spacing along the row. Sterling Onion seeds can be planted with our Hoss Garden Seeder. We recommend using a #1 seed plate and modifying the hole size slightly to accommodate the onion variety being planted. For denser plantings, more holes may need to be drilled to accommodate a thicker spacing.

For transplanting, plant one seed per cell in our heavy-duty seed starting trays. Once the green stems reach 6-8″ in length and/or they can be easily pulled from the seed trays, the transplants are ready to go in the ground. Transplant onions 4-6″ apart along the row with a row spacing of 24″. If drip irrigation is used, onions may be planted on double rows with drip irrigation in the middle. We suggest burying the drip tape 3-4″ deep and planting on both sides of the tape.

Onions are heavy feeders and will require significant nutrient inputs throughout their lifespan. We recommend feeding them with our 20-20-20 and Ammonium Sulfate fertilizers. Fertilize with 20-20-20 shortly after transplanting. The phosphorous and potassium in the 20-20-20 fertilizer will help to promote solid root development, while the nitrogen will promote vegetative growth. Once transplants are established, we recommend side-dressing or injecting with our Ammonium Sulfate fertilizer.  Side dress or inject 1 cup per 20 feet of linear row every 3-4 weeks after transplanting.

Sterling Onion Planting Information

Planting Method: transplant

When to Plant: early spring

Planting Depth: 1/4″

Seed Spacing: 4″

Row Spacing: 12-18″

Days to Maturity: 95

Disease Resistance: Basal Rot, Pink Root

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