Cucurbita pepo – Zucchini

A staple of summer cuisine, Zucchini (Cucurbita pepo) is a frost-tender annual grown for its fleshy, delicious fruit. A popular addition to ratatouille, mixed grills, summer salads, and stir-fries, Zucchini, also called Courgette or Baby Marrow, is easy to grow and prolific in the garden.

What is Zucchini?

• Zucchini is a summer squash in the Cucurbitaceae plant family, alongside melons, spaghetti squash, and cucumbers.
• Although often considered a vegetable, Zucchini is botanically classified as a fruit, as it grows from a flowering plant and contains seeds.
• Zucchini are native to Central America and Mexico but are now one of the most popular summer squashes in the United States and worldwide.
• As a variety of summer squash, they are harvested and eaten while immature.
• Zucchini fruit is typically any shade of green, though some varieties are golden or bi-color.
• The flesh is creamy white with a spongy yet firm texture, with a sweet summer squash flavor and nuances of peppercorn and nutty undertones.
• The skin, seeds, and flesh are all edible and loaded with nutrients.
• In addition to the fruit, the flowers are also edible and offer a mild, squash-like flavor.
• Popular Zucchini cultivars include Black Beauty, Caserta, Cocozelle, Gadzukes, Gourmet Gold, Zephyr.

Health Benefits of Zucchini

• While Zucchini are a flavorful addition to many dishes, they also provide health benefits.
• Zucchini are low in calories (94% water) but are rich in vitamins, minerals, and antioxidants.
• Vitamin A: one cup of Zucchini provides 40% of your daily needs. This vitamin is essential for your eyes, immune system, heart, and kidneys.
• Manganese: one cup of Zucchini provides 16% of your daily needs. Manganese helps the body form bones, blood clotting factors, connective tissue, and sex hormones.
• Vitamin C: one cup of Zucchini provides 14% of your daily needs. Vitamin C strengthens the immune system.
• Zucchini also contain small amounts of iron, calcium, zinc, and several other B vitamins.
• Zucchini are rich in antioxidants, such as lutein, zeaxanthin, and beta-carotene, that help protect your body from damage by free radicals.
• Don’t skip the skin—it contains the most nutrients!
• Nutrition Facts (one cup): 17 calories, 1 gram of carbs, 1.6 grams of protein, 0 grams of fat, 1 gram of fiber.

Cooking with Zucchini

• Zucchini are mild in flavor and one of the most versatile summer squashes.
• Sliced Zucchini can be grilled, steamed, sautéed, or battered and fried.
• Zucchini can be stuffed with meats, cheeses, or grains and then baked.
• They can be an excellent low-carb substitute for traditional noodles in pasta preparations.
• While they are usually served cooked, Zucchini work well in salad recipes, with dips, or as a wrap.
• The Zucchini flowers have a soft, delicate texture and can be stuffed with soft cheeses and herbs, then battered and fried.
• Zucchini will store best when kept dry and refrigerated for one to two weeks.

Growing Zucchini

• Most zucchini varieties have a compact, bushy habit and grow up to 2-4 ft. tall and wide (60-120 cm). Some trailing or climbing cultivars may produce stems 6-10 ft. long (1.8-3 m) and require more room or support.
• They perform best in fertile, organically rich, moist but well-drained soil with a slightly acidic to neutral pH, generally around 6.0-6.8. Plant them in a sheltered location receiving full sun, with at least 6-8 hours of direct sunlight per day.
• If the soil lacks nutrients or organic matter, incorporate well-rotted manure or compost before planting.
• Keep the soil consistently moist but not waterlogged. Irregular watering or drought stress can reduce growth and fruit production.
• Water at the base of the plants whenever possible and avoid repeatedly wetting the foliage, particularly late in the day. Good air circulation and dry foliage help reduce disease problems.
• Depending on the cultivar and growing conditions, zucchini are generally ready to begin harvesting about 45-60 days after sowing.
• Zucchini are usually direct-sown after the danger of frost has passed and the soil has warmed to at least 60-65°F (15-18°C).
• Seeds may also be started indoors about 2-4 weeks before the last expected spring frost. Because squash roots dislike disturbance, sow seeds in individual biodegradable or easily removable pots and transplant seedlings carefully after frost danger has passed.
• Planting individually or in rows: Sow 2-3 seeds about 1 in. deep (2.5 cm) at each planting position. Space planting positions 24-36 in. apart (60-90 cm), with rows approximately 3-4 ft. apart (90-120 cm). Once seedlings are established, thin each position to the strongest plant.
• Planting in hills: Sow 3-5 seeds about 1 in. deep (2.5 cm) in each raised mound. Space hills approximately 4-6 ft. apart (1.2-1.8 m), depending on the cultivar. Thin to the strongest one or two plants per hill after germination.
• Benefits of planting in hills: Raised mounds can warm more quickly in spring and improve drainage. Grouping flowers within a planting area may also make them easier for pollinating insects to visit.
• Water thoroughly after sowing or transplanting.
• Cover young plants with a floating row cover to protect them from late cold spells and insect pests.
• Remove the row cover when flowering begins so bees and other insects can reach the flowers for pollination.
• Apply an organic mulch after the soil has warmed to conserve moisture, suppress weeds, and keep developing fruit away from wet soil.
• For a longer harvest, make one or more additional sowings at intervals of approximately 2-3 weeks, provided the remaining growing season is long enough for the plants to mature.
• In fertile soil, zucchini may require little supplemental feeding. Where growth is weak, apply a balanced fertilizer according to label directions. Once flowering and fruiting begin, avoid excessive nitrogen, which can encourage abundant leaves at the expense of fruit.
• Rotate crops: Avoid growing zucchini or other members of the cucurbit family, including squash, pumpkins, cucumbers, and melons, in the same location more than once every three or four years.
• Zucchini may be affected by several pests. Watch for aphids, cucumber beetles, squash bugs, squash vine borers, slugs, and snails.
• Potential diseases include bacterial wilt, Choanephora fruit and blossom rot, downy mildew, powdery mildew, and gray mold or Botrytis.

Plant Hand Pollination

• Zucchini plants produce male and female flowers. However, only pollinated female flowers produce fruit.
• Bees are the main pollinators of Zucchini plants.
• In case of poor pollination, because of weather conditions or a lack of pollinators, you can try to hand-pollinate your plants yourself.
• Remove a male flower (no swelling at its base) and brush the central parts against the center of a female flower (female flowers have a tiny fruit at the base).
• If the female flower is pollinated, it will shrivel and closes, and a tiny zucchini will begin to form and grow into a full-size fruit.
• If there is no pollination, the tiny fruit will shrivel and drop from the plant.

Harvesting and Storing

• Harvest time depends on the variety, but usually, Zucchini are the most tender and have the best flavor when they are young.
• Harvest them when they are 3 and 8 inches long (7-20 cm) before the flesh gets woody and the seeds harden.
• Carefully cut fruits off the plant with pruners or a knife.
• Regular harvesting will encourage more fruits to develop.
• The flowers can be harvested too! They have a slightly sweet flavor and can be stuffed and fried or simply eaten raw in salads.
• Finish harvesting before the first fall frost. Zucchini is highly susceptible to frost and heat damage.
• To help them store longer, harvest with at least an inch of stem still attached.
• Zucchini will keep best when kept dry and refrigerated for one to two weeks.

Best Companion Plants

A good example of companion planting is The Three Sisters Garden. Practiced by Native Americans thousands of years ago, this garden includes corn, beans, and squash. The tall corn provides shade for the lower squash but also stops the squash vine borer beetle. Corn also provides support for the bean plants to climb up. The beans enrich the soil with nutrients for both corn and squash. And the large leaves of the squash vines create a protective mulch that helps retain moisture while suppressing weeds. Another added benefit is the prickly vines of the squash deter the raccoons from stripping the corn cobs.

• Beans fix nitrogen and add nutrients that improve the soil, benefitting the plants that are growing beside them.
• Borage flowers attract beneficial insects and help deter pests from your plants. Borage also enriches the soil and improves the growth and flavor of squash plants. As a bonus, the flowers are edible.
• Buckwheat attracts spiders and ground beetles, keeping them away from the squash plants.
• Catnip is good for deterring ants, weevils, squash bugs, Japanese beetles, flea beetles, and mice.
• Corn provides shade and stops the squash vine borer beetle.
• Dill flowers attract beneficial insects such as hoverflies and ladybugs (prey on aphids) and predatory wasps (prey on caterpillars and other insects), which help keep pest levels down.
• Chamomile attracts hoverflies and wasps, repels Mexican bean beetles, and accumulates calcium, potassium, and sulfur, later returning them to the soil. Growing chamomile is considered a tonic for anything you grow in the garden.
• Legumes such as peas help your squash plants receive enough nutrients by fixing the nitrogen and increasing the nutrients in the soil.
• Lemon balm also repels squash bugs, which makes it a good companion plant for squash and pumpkin plants.
• Lovage improves the flavor and vigor of most plants and offers a good habitat for ground beetles.
• Marigolds help deter beetles.
• Marjoram is a friend to all plants and helps improve growth and flavor.
• Nasturtium is known to deter whiteflies, wooly aphids, squash bugs, cucumber beetles, and other pests.
• Oregano provides general pest protection. It attracts hoverflies and Syrphidae and repels aphids.
• Radish is thought to protect all squash family members from the squash borers.
• Spinach: It’s a good use of space because, by the time squash plants start to get big, the spinach is ready to bolt.
• Sunflowers grow tall and provide helpful shade for squash plants in hot summer areas.
• Tansy helps concentrate potassium in the soil, benefiting nearby plants. It also repels cutworms, cabbage worms, squash bugs, striped cucumber beetles, Japanese beetles, ants, flies, mosquitoes, and fruit moths.

Worst Companion Plants

Avoid planting these vegetables in your home garden nearby your Zucchini and squash plants.

• Fennel: Most plants dislike fennel, which has an inhibiting effect on them.
• Potatoes: These root vegetables can deplete the soil of nutrients and starve your squash plants nearby.
• Sweet potatoes will compete with squash plants for space: these vigorous growers like to spread out.