Time to Start Seedlings
Two to four weeks before the last frost seedlings should be started indoors. If planted outdoors, wait until the outside temperature is consistently 65°F (18°C) or higher. Soil temperature should be at least 60°F (16°C) two inches below the surface.
Where and How to Start Seedlings
Most gardeners start their zucchini seedlings by direct sowing into the garden or in containers; however, some prefer to get a head start by starting seedlings indoors in small containers. Here are some instructions on each method of planting:
Direct Sown Seedlings
Mature zucchini plants can have a diameter of 24-36 inches. Choose a location that can accomodate this large plant. Here are some other requirements for thriving plants:
- Fertile, well composted soil
- Six to seven hours of direct sunlight
- Soil that is well drained
- Soil that did not grow cucurbit family vegetables the previous year
If these conditions are met, start by sowing about three seeds every 36 inches in row gardens. Sow 1 inch deep. When the seedlings have true leaves, the weakest of each group of three should be cut down at the base of the seedling.
If planting zucchini in hills, sow 1 inch deep two seeds together in six locations of 24-36 inches apart. The weakest seedlings should be cut down when the true leaves develop.
Small Container Seedlings
Zucchini plants have large, fast-growing root systems that can be easily damaged with transplanting. When starting seedlings in containers, it is always best to sow seeds into 5-inch or deeper containers. Here are the steps to grow potted seedlings:
- Fill containers with quality seed-starter mix that is moistened.
- In each container sow two seeds 3/4 inches deep.
- Cut at base, the weakest of seedlings when true leaves appear.
- Gradually expose young seedlings to more sun and outdoor temperatures.
- Plant in the garden when air and soil temperature reaches recommended levels.
Large Container Seedlings
The sprawling nature of a zucchini plant requires a container that has at least a 5-gallon capacity and has a diameter of 24 inches or more. Line the bottom of the proper container with small pebbles followed by a nutrient-dense organic soil.
Starting transplants by directly sowing seeds into the large containers can be easily done. Sow about three seeds in each pot to a depth of 1 inch. Thin to the healthiest plant by cutting at the base the weaker ones. Indoor grown transplants can also be planted in large pots. Be sure to water seedlings thoroughly.
