How to Grow Zucchini

Every vegetable gardener should make room for at least one zucchini plant (Cucurbita pepo var. cylindrica) -- with regular picking, zucchini plants produce fruit all summer. These annuals grow 1 to 2 1/2 feet tall and 2 to 3 feet wide, depending on the variety, and produce fruits that range in color from yellow through green to nearly black.

Zucchini plants grow best in warm, sunny, moist conditions. When the soil temperature is above 65 degrees Fahrenheit, grow zucchini plants in an area that receives six to 10 hours of sunlight per day. The soil pH should be between 6.0 and 7.5. Space zucchinis 3 feet apart in blocks, or 2 to 3 feet apart in rows spaced 3 to 6 feet apart. Water zucchinis when the soil surface is dry, applying enough water to puddle around the plants, but don't saturate the soil. Water the plant bases and avoid splashing the leaves, which encourages leaf diseases. In hot weather zucchini plants may need water two to three times per week.

Soil rich in organic matter provides nutrients for zucchinii, and organic fertilizers can help boost plants. Over-fertilization with nitrogen-rich fertilizers encourages leafy growth at the expense of fruits in zucchini plants. Plants growing in soil enriched with compost or well-rotted manure may not need fertilizer. In poorer soils, feed zucchini plants with organic fertilizer, such as an organic fish and seaweed product. Dilute a water-soluble 2-3-1 organic fish and seaweed fertilizer at a rate of 1/8 cup per 1 gallon of water, and apply about 20 fluid ounces of fertilizer solution per zucchini plant. Apply the solution to the plant's base when it begins to flower and every two to three weeks. You can use fertilizer solution to water the plants.

Zucchinis need hand-pollination when there are low numbers of bees. Female zucchini flowers have a swollen stem, and male flowers have a longer, slim stem. Bees transfer pollen from male to female flowers, but in weather that's too hot for bees and in places where there are few bees, female zucchini flowers aren't pollinated. The female flowers drop and don't set fruit. To hand-pollinate zucchinis, remove an open male flower with loose, powdery pollen. Pull off the petals, taking care not to damage the inner stamen. Brush the stamen against the protruding stigma inside open female flowers. The best time for hand-pollinating zucchinis is in the morning before the flowers close in midday heat. If there are no female flowers, it's probably too early in the season for pollination. Zucchinis usually produce only male flowers when the plants are young.

Harvest zucchini fruits before they mature to encourage more fruit. Left to their own devices, zucchini fruits grow large, woody and unpleasant to eat, and the plants stop producing fruit. For tender, sweet fruit, pick zucchinis when they're 6 to 8 inches long and 1 1/2 to 3 inches in diameter. Put on gloves if your hands are sensitive to the fine, prickly hairs on zucchini leaves and stems, and sterilize pruning shears by wiping the blades with a cloth soaked in rubbing alcohol. Cut the fruit stems where they join the plant. You can also pick immature fruit with the flower still attached. Don't try to pull the fruits off the plant because this can damage the plant.