Caliber, (F1) Onion Seeds

Caliber (F1) Onion Seed

Vigorous long-day hybrid produces firm, high-quality yellow bulbs
Reliable disease package supports consistent western harvests
Uniform onions size well under favorable growing conditions
Excellent storage potential serves kitchens through winter

See product details

Key Attributes

Botanical Name

Allium cepa

Days to maturity

122 Days

Sun

Full Sun

Packet

250 Seeds

About Caliber, (F1) Onion Seed, Onion Seed

Caliber is a late-season yellow long day for the western United States known for vigor, disease resistance, yield, and storage capabilities. Caliber is a Celebrate hybrid with a healthy plant with solid roots and strong and erect tops that assist in providing thrips tolerance and make applications easier. Caliber has a consistent rich bronze scale in super colossal bulbs with single centers that do very well with a mechanical harvest. Caliber has a reputation for storing very well long term.

Growing details

Planting

Sow Depth

1/8"

Days to Germination

7–14 days

In-row plant spacing

3-4"

Row Spacing

12-18"

Plant profile

Maturity

Summer

Life Cycle

Annual

Plant Height

24 inches

Growth Habits

Clumping, Upright

Type

FULL SIZE ONIONS

Seed & variety

Seeds Per Ounce

6,622

Color

Yellow

Seed Type

Hybrid

Growing Season

Cool-Season Crop

Before Planting

For Onion, select a full-sun location with fertile, loose, well-drained soil. Incorporate compost and use a soil test to correct phosphorus, potassium, and pH while avoiding fresh manure. Select the correct short-, intermediate-, or long-day type for your latitude, and prepare a smooth, weed-free bed before sowing or setting transplants.

Planting

Start onion seed indoors 10–12 weeks before the last spring frost, or direct sow as soon as the soil can be worked. Give indoor seedlings strong light and steady moisture, harden them gradually, and transplant while weather is cool. Thin bulb onions to 3–4 inches apart.

Watering

Provide about 1 inch of water weekly, keeping moisture steady while bulbs enlarge. Water at soil level and avoid saturation; reduce and then stop irrigation as tops naturally fall and bulbs approach maturity.

Fertilizer

Apply nitrogen in light side-dressings during early leaf growth, following soil-test recommendations. Stop feeding once bulbs begin enlarging; late nitrogen delays maturity and reduces storage quality.

Harvesting

Harvest onions when most tops naturally yellow and fall. Lift bulbs gently rather than pulling, then cure them in a warm, dry, ventilated place until necks and outer skins are fully dry.

Tips

Keep beds weed-free because onions compete poorly. Gently expose bulb shoulders as they enlarge rather than hilling soil around them, and select the proper day-length type for your latitude.

AVG. Seeding Rate

1 oz./25', 1M/50', 5M/250', 25M/1,250', 580M/acre at 20 seeds/ft., in rows 18" apart.

Disease Resistance Abbreviations

PR, F

Pink Root, Fusarium Wilt

Pests & Diseases

Onion seed can introduce Botrytis neck rot, downy mildew, purple blotch, and bacterial diseases; damping-off threatens young seedlings. Purchase tested seed, use sanitized trays, and avoid overly dense sowing. Rotate alliums, keep leaves dry, and discard seedlings with basal softening, water-soaked lesions, or abnormal twisting.

Onion thrips, onion maggots, leafminers, and cutworms are common. Rotate allium crops, use insect netting early, remove cull bulbs and residue, and inspect folded leaves for feeding damage.