How to Grow Hawkeye Soybean

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Hawkeye Soybean

Glycine max 'Hawkeye'

vegetable

Hawkeye is a determinate soybean cultivar bred for high yield and reliability in temperate climates. Known for its consistent production and relatively short maturity period, it has been a popular commercial and garden variety since its development in the mid-20th century. The plant produces nitrogen-fixing nodules on its roots and yields protein-rich pods suitable for fresh consumption, drying, or processing.

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Example Hawkeye Soybean timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Hawkeye Soybean

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Hawkeye Soybean

    Around Jul 21

    ≈ 95 days after planting

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

Growing Conditions

☀️
Sun: Full sun, minimum 6-8 hours daily, preferably 8+ hours
💧
Water: Moderate to consistent watering; requires 18-25 inches of rainfall or irrigation during growing season. Water deeply once or twice weekly depending on rainfall. Avoid waterlogging; ensure good drainage. Most critical during flowering and pod-fill stages.
📏
Spacing: 4-6 inches between plants in rows 24-30 inches apart inches
📅
Days to maturity: 95-110 days
🌱
Planting depth: 1.0-1.5 inches deep

Soil

Type: Well-draining loamy or clay loam soil
pH: 6.0-7.0
Amendments:
Compost or well-rotted manure for organic matter Phosphorus and potassium before planting Avoid excessive nitrogen (plant fixes its own via nodulation)

Growing Zones

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Zones 5-7 are ideal; can succeed in zones 4-8 with proper timing

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

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Growth Stages

1

Seedling (VE-V2)

7-14 days

Seeds germinate and emerge as cotyledons with initial true leaves appearing. Plants are 2-4 inches tall with simple leaf structure.

Ensure consistent soil moisture. Keep weeds controlled to reduce competition. Thin seedlings to proper spacing if direct-seeding. Protect from heavy rain that could cause damping off.

2

Vegetative Growth (V3-V6)

3-4 weeks

Plant develops multiple true leaves and becomes bushy. Height reaches 8-18 inches. Root nodulation becomes established. Stems thicken and begin branching.

Maintain consistent moisture. Begin regular weeding to prevent resource competition. Watch for early pest damage (beetles, Japanese beetles). Ensure proper spacing for air circulation.

3

Pre-Flowering to Flowering (R1-R2)

2-3 weeks

Small purple or white flowers appear in leaf axils. Plant height reaches 24-36 inches (determinate variety). Increased leaf area and continued stem development.

Increase watering during this critical stage. Flowering is sensitive to water stress and temperature extremes (heat). Monitor for spider mites and other pests. Avoid disrupting soil or damaging roots.

4

Pod Development and Pod Fill (R3-R5)

3-4 weeks

Small pods form and enlarge rapidly. Leaves may yellow as plant shifts energy to pods. Pods grow from 0.5 to 2 inches long with developing seeds inside.

Critical water period—maintain consistent moisture without waterlogging. Stop excessive nitrogen application. Continue pest monitoring. Reduce or stop fertilizing; plant should rely on stored energy and nodule nitrogen.

5

Mature/Harvest Ready (R7-R8)

2-3 weeks

Pods dry and turn brown. Seeds inside pods are hard and fully mature, rattle when shaken. Foliage browns and most leaves drop. Plant achieves final height of 28-40 inches.

Reduce watering as plant matures. Allow pods to fully dry on plant for mechanical harvesting or handpicking. Harvest when moisture content is 12-14% for storage. Entire plant can be cut and dried in bundles.

Companion Planting

Plan your garden →

Plant with:

Corn (intercropping - traditional three sisters variant) Squash or pumpkin Marigold Nasturtium Borage

Avoid planting near:

Other legumes (peas, beans) - may compete for nitrogen fixation resources Fennel Alliums (onions, garlic) - may inhibit growth

Common Pests

  • Handpick early morning, use row covers on young plants, apply neem oil or spinosad. Encourage natural predators.

  • Increase humidity and irrigation to discourage mites. Apply miticide spray or neem oil if infestation is severe. Remove heavily infested leaves.

  • Use row covers until flowering. Handpick beetles and yellow egg clusters. Apply spinosad or pyrethrin if population is high.

  • Monitor for small holes in leaves. Apply Bt (Bacillus thuringiensis) for organic control or spinosad. Encourage parasitic wasps.

  • Use strong water spray to dislodge. Apply insecticidal soap or neem oil. Attract ladybugs and parasitic wasps. Monitor population levels before treating.

Uses

🍳

Fresh Edamame and Boiled Pods

Culinary

Young green pods can be boiled and salted as a nutritious snack, or pods shelled for fresh soybeans. Mature dried beans are ground into flour, made into tofu, tempeh, miso, or soy sauce, or sprouted for fresh shoots. [source]

🍳

High-Protein Legume Dishes

Culinary

Dried cooked soybeans are used in soups, stews, salads, and grain bowls. Ground soybean flour enriches baked goods and pasta. The complete protein profile makes soybeans valuable for vegetarian and vegan diets. [source]

🏠

Nitrogen Fixation and Soil Improvement

Household

Like all legumes, Hawkeye soybeans form symbiotic relationships with nitrogen-fixing bacteria (Bradyrhizobium), naturally enriching soil with bioavailable nitrogen. Plowing under or composting plant residue increases soil fertility for subsequent crops. [source]

💊

Isoflavone and Phytoestrogen Content

Medicinal

Soybeans are rich in genistein and daidzein isoflavones, plant compounds studied for potential health benefits including bone health, cardiovascular function, and menopausal symptom management. [source]

🎨

Natural Dye and Biodegradable Materials

Craft

Soybean plants and pods can be used to extract natural dyes for textiles. Soy wax derived from soybean oil is used in sustainable candle-making as an eco-friendly alternative to petroleum-based paraffin. [source]

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

Harvest Tips

For fresh/edamame consumption: Harvest green pods when they reach full size (2-2.5 inches) but before seeds harden, typically 70-90 days after planting. Boil immediately or freeze. For dry beans: Allow pods to dry completely on plant, then pick and shell by hand or with mechanical equipment. Harvest when pods are brown and crispy. Store dried beans in cool, dry conditions (50°F, 50% humidity) in sealed containers for year-round use.

Fun Facts

  • 🌱 The Hawkeye cultivar was developed at Iowa State University and named after the University of Iowa's mascot, becoming one of the most widely grown soybean varieties in the U.S. Corn Belt for decades.
  • 🌱 Soybeans form a mutualistic relationship with Bradyrhizobium bacteria in root nodules—a single plant can fix 50+ pounds of nitrogen per acre, reducing or eliminating the need for synthetic nitrogen fertilizers.
  • 🌱 Hawkeye soybeans are 'determinate,' meaning they reach a set height and pod all their beans within a relatively narrow window, making them ideal for mechanical harvest and commercial production.

Gardening Terms

New to gardening? Learn about terms used in this guide:

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