How to Grow Cosford Cob

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Cosford Cob

Corylus avellana 'Cosford Cob'

shrub

Cosford Cob is a premium hazelnut cultivar prized for its large, flavorful nuts and reliable cropping. This deciduous shrub grows 12-15 feet tall and produces abundant yields of sweet, oil-rich hazelnuts in their distinctive husks. It is a popular choice for both commercial and home gardeners seeking superior nut quality.

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Example Cosford Cob timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Cosford Cob

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Cosford Cob

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Cosford Cob dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily; tolerates partial shade but produces fewer nuts
💧
Water: Moderate watering; keep soil consistently moist during growing season but not waterlogged. Established plants are drought-tolerant once roots develop.
📏
Spacing: 144 inches
📅
Days to maturity: 1080
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Planting depth: Plant bare-root or container plants at same depth as they were growing; top of rootball level with soil surface

Soil

Type: Well-draining loamy soil, slightly acidic to neutral
pH: 6.0-7.5
Amendments:
Compost or well-rotted manure Peat moss for acidic soils Gypsum if soil is compacted

Growing Zones

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Thrives in zones 5-7, hardy to zone 4

4a 4b 5a 5b 6a 6b 7a 7b 8a

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Growth Stages

1

Establishment (Year 1-2)

2 years

Young shrub focuses on root development and establishing a strong framework. Little to no nut production during this period.

Water regularly during dry periods, mulch around base, prune to establish open center shape with 3-4 main stems, stake if necessary in windy locations

2

Development (Year 3-4)

2 years

Shrub grows vigorously and begins to flower. First significant nut crops appear but remain light as plant matures.

Continue pruning to shape and remove crossing branches, thin crowded growth, maintain open center for air circulation and light penetration

3

Productive (Year 5+)

15+ years

Mature shrub produces abundant catkins in late winter/early spring and sets a heavy crop of nuts developing throughout summer.

Prune after harvest to remove dead wood and maintain shape, thin dense growth, ensure cross-pollination by having compatible pollinators nearby (e.g., 'Barcelona', 'Ennis')

4

Flowering (Late Winter to Early Spring)

4-6 weeks

Male catkins elongate and release pollen; tiny red female flowers appear inconspicuously on buds. This occurs before leaf emergence.

No special care needed; pollen dispersal is wind-driven; ensure nearby pollinator cultivars are flowering at same time

5

Nut Development & Maturation (Summer to Early Fall)

3-4 months

Nuts grow within leafy husks, increasing in size through summer. Kernel fills and hardens; husks turn brown as nuts mature in August-September.

Water during dry spells if nuts are swelling, monitor for pests and diseases, no pruning during this period

Companion Planting

Plan your garden →

Plant with:

Filbert (other hazelnut cultivars like 'Barcelona' for pollination) Nitrogen-fixing legumes like clover as groundcover Heather Gaultheria Bilberry

Avoid planting near:

Walnut trees (juglone toxicity) Shallow-rooted plants that compete for moisture

Common Pests

  • Collect and destroy fallen nuts promptly, rake debris in fall, use pheromone traps, apply neem oil or spinosad in early summer

  • Prune out affected buds in winter, spray with sulfur in early spring before bud break, ensure good air circulation

  • Prune out infected branches at least 12 inches below visible damage, sterilize pruning tools between cuts, remove all dead wood, improve air circulation

  • and

    Install tree guards or netting, harvest nuts promptly when ripe, provide alternative food sources away from trees

Uses

🍳

Premium table nuts and baking

Culinary

Cosford Cob hazelnuts are prized for their sweet flavor and high oil content, making them ideal for eating fresh, roasting, or grinding into hazelnut flour and paste. They are a key ingredient in European confectionery and spreads. [source]

🍳

Oil and nut butter production

Culinary

The high oil content (approximately 60-70%) makes Cosford Cob ideal for pressing into hazelnut oil used in cooking and dressing. Nuts also process well into creamy hazelnut butter. [source]

🏠

Ornamental landscaping and wildlife habitat

Household

Beyond nut production, the shrub provides attractive form, spring catkins, and valuable food source for wildlife including birds and small mammals, making it an excellent dual-purpose landscape plant. [source]

💊

Traditional herbal and nutritional uses

Medicinal

Hazelnut kernels are nutrient-dense, rich in monounsaturated fats, vitamin E, magnesium, and copper. Historically, hazel branches were used in traditional herbalism and dowsing. [source]

🎨

Woodworking and traditional crafts

Craft

Hazel wood is flexible and strong, traditionally used for wattle-and-daub construction, basket weaving, and coppicing to produce rods for hurdle-making and garden features. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Harvest in late August to September when husks split and nuts fall naturally or shake free with gentle branch vibration. Collect daily as nuts mature unevenly. Dry nuts in a single layer in shade with good air circulation for 2-3 weeks before storage. Store shelled or in-shell nuts in cool, dry conditions (50°F or below, <70% humidity) for extended shelf life.

Fun Facts

  • 🌱 Cosford Cob is one of the few English hazelnut cultivars and has been grown since the 1800s in Norfolk, England, where it remains a commercial crop. Its name derives from Cosford, Norfolk.
  • 🌱 Hazelnut pollen is one of the most allergenic plant pollens in temperate regions; the early winter/spring flowering means pollen is dispersed before most other plants, making it a primary allergen for hayfever sufferers.
  • 🌱 A mature Cosford Cob shrub can live 50-70+ years and will remain productive for decades if properly maintained, making it a worthwhile long-term investment for home growers.

Gardening Terms

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