How Zucchini Grows
All zucchini plants are started from seed sown directly into the garden or containers. The containers may be large permanent containers or temporary small seedling containers.
Be prepared for rapid growth once the seeds germinate in about 10-14 days. The zucchini seedlings start out larger than most other vegetable seedlings. Leaf stems quickly grow upward and outward 3 feet or more. Leaves at the end of the stems expand forming a canopy. Most zucchini varieties are bush-like.
Where to Grow
Zucchini plants grown in large containers or in a garden all have essential requirements in order to thrive. These requirements are:
- Three square feet or larger area for growing
- Six or more hours of direct sunlight per day
- Well-drained soil
- Well composted and fertile soil
- Planted in an area that didn’t grow cucurbit vegetables in previous year
Heat-loving zucchini plants are usually started in the spring. Seeds must be planted in the garden soil when the danger of frost is over.
It is best to use air and soil temperatures as a guideline to the timing of planting. Zucchini seeds should be sown after the outside temperature is consistently 65°F (18°C) or higher. A soil temperature 2 inches below the surface should be at least 60°F (16°C). In some warmer locations, seeds sown in summer produce a late crop before the first frost.
In an 8 feet diameter hill, sow six seeds grouped by two 1 inch deep and 36 inches apart. When the seedlings have true leaves, cut down the weakest one of each group. If planting is done in rows, sow the seeds one inch deep and 36 inches apart.
Zucchini seedlings started in a greenhouse or home should be started two to four weeks before the last frost. Fill containers that are at least 5 inches deep with a quality seed-starting mix that is moistened. Sow zucchini seeds 3/4 inches deep. Grow under 15 hours of light per day in a greenhouse or room that is at least 70°F (21°C).
Seedlings have to be exposed to outside environmental conditions slowly. On warm days, increase the exposure a bit more each day. Plant in the garden or large containers outside at the same time you would sow zucchini seeds outdoors.