How to Grow Zucchini

General

Zucchini squash come in a variety of shapes and colors. Bush varieties take up relatively little space, and if kept picked will keep producing right up to frost. These tender skinned North American natives are the very symbol of summer's bounty. Zucchini are heavy producers of delightful fruit that can be baked, stir-fried or eaten fresh with a dip. Gardeners don't need to let themselves get swamped with an over abundance of zucchini either. If you pick the flowers, you get fewer fruit. The flowers are a gourmet treat; excellent fresh in a salad, coated in batter and deep fried, or added to soups at the last minute. Picking the flowers and the young squash encourages more blossoms to grow for harvest into the autumn.

Latin

Cucurbita pepo
Cucurbitaceae Family

Difficulty

Easy.

Season & Zone

Season: Warm season.
Exposure: Full-sun.
Zone: All.

Planting Seeds

Zucchini seeds can be direct-seeded, or used to raise transplants.
 
Direct seed: sow 3 or 4 seeds above an area which has been amended with complete organic fertilizer and manure. When the plants are 7-10cm (3-4") tall, cut out (don't pull) the shortest, leaving one strong plant. If it rains, and the soil cools, this planting may fail so replant or use transplants. They need warm, but not wet soils.
 
Raising transplants: Start seeds 3 weeks before your last frost date. Using bottom heat is helpful. Set one seed in each 7cm (3") pot. For best results, move to the garden before the plant has 4 true leaves.
 
Days to emergence 4–9, depending on soil temperature. Germination temperature is 60 to 105 F, but will germinate at soil temperatures as low 65 F (preferably 70 F or more). Optimal soil temperature for germination: 25-35ºC (68-95ºF). At least 80% of seeds will germinate in optimal conditions. Usual seed life: 4 years.

Preparing Soil

Zucchini prefers loose, well-drained, fertile soil high in organic matter with a pH between 5.8 and 6.8. Plenty of consistent moisture is needed from the time plants emerge until fruits begin to fill out. Place zucchini in a hot area of your garden.

Planting

Rows 1–2.4m (3–4') apart with plants spaced 45–60cm (18–24") apart. Even the bush zucchini are big plants and most gardens do not need more than 2 or 3. You need to leave room so you can get to the plants to harvest them regularly.

Diseases & Pests

Pests:
Squash bug - Hand pick. Bury or compost plant residues after harvest.
Squash vine borer - Remove by hand and destroy.
Striped cucumber beetles - Construct tents of fine netting or cheesecloth or use floating row covers over young plants. Put in place at planting and remove at flowering. Control of beetles may be a factor in preventing bacteria wilt

Diseases:
Bacterial wilt (Erwinia tracheiphila) - Remove and destroy infested plants. If striped or spotted cucumber beetles appear control as soon as possible.
Powdery mildew - Avoid wetting foliage if possible. Water early in the day so that above ground parts will dry as quickly as possible. Avoid crowding plants and eliminate weeds around plants and garden area to improve air circulation.
Viral disease - Remove and destroy entire infested plant along with immediately surrounding soil and soil clinging to roots. Eliminate wild cucumber and milkweed nearby. Control aphids early in the season by washing off with water as needed early in the day. A hard stream of water can be used to remove many aphids.

Harvest

Pick regularly to encourage the plant to keep on fruiting. Zucchini leaves are often very prickly, so pull delicate skinned fruit out carefully. Fully mature zucchini have a hard skin: chickens like them.