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Cucurbita pepo

Summer squash

Cucurbitaceae Mexico and eastern North America

Attracts Pollinators Container Friendly

Native to North America

SunFull Sun

WaterMedium

Overview

Cucurbita pepo is a frost-tender annual in the gourd family covering summer squash, courgette, marrow, acorn squash, pumpkin and ornamental gourd cultivars. Bush selections form a compact rosette 24-36 inches (60-90 cm) tall and 30-48 inches (75-120 cm) across on shortened internodes, while vining selections trail 6-15 feet (1.8-4.5 m). Stems are hard, angular and bristly; leaves are alternate, palmately five-lobed, 8-14 inches (20-35 cm) across, and frequently carry silver-grey mottling along the veins as a cultivar trait rather than a disease symptom. Plants are monoecious, with separate male and female flowers on the same stem, the flowers yellow to orange, funnel-shaped and 2-5 inches (5-13 cm) across. Fruit development depends on insect transfer of pollen, so low bee activity leaves young fruit to yellow and abort at 1-2 inches (2.5-5 cm). Summer types are cut immature at 6-8 inches (15-20 cm) some 45-55 days from sowing, while winter types within the same species are cured at 80F (27C) for ten days and stored. Powdery mildew colonises the foliage from midsummer, and squash vine borer and squash bug shorten the cropping period across eastern North America.

Native Range

Cucurbita pepo was domesticated in Mexico, with seed remains from Guila Naquitz cave in Oaxaca dated to roughly 10,000 years ago, an earlier date than maize or beans from the same region. A second, independent domestication of Cucurbita pepo ssp. ovifera took place in eastern North America about 5,000 years ago. Free-living populations persist in Mexico and the southern United States, including Cucurbita pepo var. texana along Texas river systems.

Suggested Uses

Grown in vegetable beds and raised beds at 24-36 inch (60-90 cm) spacing, and in containers of 10 gallons (38 litres) or larger for bush cultivars. Vining cultivars are trained on A-frames and trellises, lifting fruit clear of the soil and freeing the bed space beneath. Male flowers are cut for stuffing and frying, and ornamental gourd selections are dried for autumn arrangements.

How to Identify

Separated from other cultivated Cucurbita spp. by hard, sharply angular five-sided stems with stiff bristles, in contrast to the rounded softly hairy stems of C. moschata and the corky rounded stems of C. maxima. The fruit stalk is deeply grooved and flares abruptly where it joins the fruit. Leaves are cut into five pointed lobes with toothed margins and bear stiff hairs on both surfaces.

Appearance

Size & Dimensions

Height2' - 3'

Width/Spread2'6" - 15'

Colors

Flower Colors

Foliage Colors

Bloom Information

Bloom Period

~14 weeks

Summer Fall

Flowering starts 35-50 days after sowing and runs until frost, spanning June to September in temperate gardens. Male flowers open first, commonly 7-10 days ahead of the females, on stalks 4-8 inches (10-20 cm) long, while female flowers sit on a short stalk with a swollen ovary behind the petals. Each flower opens for a few hours after dawn and closes by midday, so pollen transfer happens within a narrow morning window. A run of cool cloudy mornings suppresses bee flight and leaves that window unused.

Detailed Descriptions

Flower Description

yellow to orange

Foliage Description

mid to dark green, often silver-grey mottled along the veins

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.0(Neutral)

357912

Soil Types

loam sand silt

Drainagewell drained

Water & Climate

Water Needs

Medium

Care & Maintenance

Care Guide

Grows in full sun with about 8 hours of direct light in warm free-draining soil at pH 6.0-7.0 worked with 2-3 inches (5-8 cm) of compost. Seed is sown direct 1 inch (2.5 cm) deep once soil holds 65F (18C), at 24-36 inch (60-90 cm) spacing for bush types and 36-48 inches (90-120 cm) for vining types. Water use runs 1-2 inches (25-50 mm) per week applied at the base, since overhead watering wets the foliage and speeds powdery mildew. A balanced feed at sowing followed by a nitrogen side-dressing as vines begin to run carries the crop; heavy nitrogen after flowering pushes leaf growth ahead of fruit. Squash vine borer larvae tunnel the stem base from June onward and cause sudden wilt, while squash bugs feed at the crown; floating row cover excludes both and is lifted at first flower for pollination. Fruit cut every 2-3 days holds the plant in flower, as maturing fruit suppresses further female bloom.

Pruning

No routine pruning is carried out on Cucurbita pepo. Lower leaves carrying powdery mildew are cut at the petiole base to slow spread, taking no more than a quarter of the canopy at one time. On trailing cultivars the vine tip is pinched at 6-8 feet (1.8-2.4 m) to hold the plant within its bed.