How to Grow Black Summer Squash

Wikimedia Commons

Black Summer Squash

Cucurbita pepo

vegetable

Black Summer is a dark green to nearly black zucchini-type summer squash with a tender, mild flavor and prolific production. It's an open-pollinated heirloom variety that produces abundant cylindrical fruits throughout the growing season. This compact bush variety is ideal for home gardens and reaches maturity quickly.

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Example Black Summer Squash timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Black Summer Squash

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Black Summer Squash

    Around Jun 6

    ≈ 50 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Black Summer Squash dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily minimum; 8+ hours ideal for maximum production
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Water: Consistent moisture; 1-2 inches per week. Water deeply at soil level to avoid wet foliage. Keep soil evenly moist but not waterlogged. Increase watering during fruit-bearing stage and in hot weather.
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Spacing: 24-36 inches between plants, rows 36-48 inches apart inches
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Days to maturity: 50-65 days from seed to first harvest
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Planting depth: 1 inch deep for seeds; plant 2-3 seeds per hill

Soil

Type: Well-draining, rich loamy soil with abundant organic matter
pH: 6.0-7.0
Amendments:
Compost Well-rotted manure Peat moss or coco coir Balanced fertilizer (10-10-10)

Growing Zones

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Thrives in zones 3-10; grown as summer crop everywhere

2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b

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Growth Stages

1

Seedling

2-3 weeks

Cotyledons emerge 3-7 days after planting; true leaves follow shortly. Plants are low-growing with hairy stems.

Maintain consistent soil moisture; thin to strongest seedling once true leaves appear. Ensure adequate light to prevent leggy growth.

2

Vegetative Growth

3-4 weeks

Plants develop multiple stems and large lobed leaves; rapid bushy growth with visible leaf expansion daily.

Water regularly; apply mulch to conserve moisture. Feed with balanced fertilizer every 2-3 weeks. Ensure good air circulation.

3

Flowering

2-3 weeks (overlapping)

Large yellow flowers appear at stem terminals; male flowers emerge first, followed by female flowers with tiny fruit behind the bloom.

Maintain consistent watering; avoid over-fertilizing nitrogen which promotes leaves over flowers. Monitor for pollinator activity.

4

Fruiting & Production

6-8 weeks (peak production)

Small green squash develop rapidly from fertilized female flowers; fruits elongate and darken to deep green-black within 6-8 days.

Pick fruits regularly at 6-8 inches to encourage continued production. Water deeply and consistently. Feed with balanced or slightly higher potassium fertilizer.

5

Peak & End of Season

4-6 weeks

Continuous fruit production throughout summer; production declines in late season as plants age or temperatures become extreme.

Continue regular harvesting; remove diseased or damaged leaves. Watch for declining vigor; replace plants if desired for fall crop in mild climates.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Fennel Potatoes Other cucurbits (within 1600 feet for seed saving) Aromatic herbs like rue

Common Pests

  • Wrap base of stems with aluminum foil; plant succession crops; inject Bt (Bacillus thuringiensis) into stems; remove infested portions and bury.

  • Improve air circulation; spray with sulfur or neem oil; remove affected leaves; plant in full sun.

  • Hand-pick eggs and adults; use row covers on young plants; plant trap crops; apply neem oil; encourage parasitic wasps.

  • Use yellow sticky traps; apply spinosad or neem oil; use row covers; remove plant debris; encourage beneficial insects.

  • Spray with strong water stream; use insecticidal soap; apply neem oil; attract beneficial insects like ladybugs and lacewings.

  • Increase humidity; spray with water; apply neem oil or sulfur; ensure adequate watering.

Uses

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Fresh Cooking & Grilling

Culinary

Black Summer squash is tender and mild when harvested young, making it perfect for quick sautéing, grilling, roasting, or raw in salads. Its delicate flavor works well with butter, herbs, garlic, and light sauces. [source]

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Preservation & Storage

Culinary

Can be blanched and frozen for winter use, pickled, or dehydrated into chips. The prolific production makes Black Summer ideal for processing and preserving excess harvests. [source]

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Abundant Home Production

Household

Black Summer is famous for its extremely prolific output—a single plant often produces 20+ fruits per season, making it excellent for feeding families and sharing with neighbors. [source]

🎨

Flowers for Consumption

Craft

The large, showy yellow flowers are edible and prized in many cuisines. They can be stuffed, fried as blossoms, or used as an attractive garnish. [source]

🦋

Pollinator Support

Wildlife

The abundant flowers attract bees, butterflies, and other pollinators, supporting beneficial insect populations in the garden ecosystem. [source]

Harvest Tips

Pick fruits when 6-8 inches long and dark green (before they turn yellow or grow too large, which diminishes tenderness). Harvest every 2-3 days during peak season to encourage continuous production. Cut with a sharp knife rather than pulling to avoid plant damage. Young, tender squash have superior flavor and texture; larger fruits tend to have tougher skin and larger seeds. Harvest in the morning when cool.

Fun Facts

  • 🌱 Black Summer is an open-pollinated heirloom variety that has been grown for decades; gardeners can save seeds from mature fruits for replanting next year.
  • 🌱 A single Black Summer plant can produce enough squash to supply a family of four for the entire summer season, with plenty left over for sharing or preserving.
  • 🌱 The name 'summer squash' distinguishes it from winter squash; summer squash are harvested immature with tender, edible skin, while winter squash are left to mature and develop hard shells for storage.

Gardening Terms

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