Growing Squash Seedlings that Transplant Well

Squash seedlings can be the beginning of lush, prolific plants that supply you and others with a bountiful harvest of delicious food. Start by choosing seed from the many squash varieties available. Don’t rely on transplants from a garden center. Their quality and lack of variety can bring disappointing results. Reward yourself with healthy transplants grown with your favorite seed.


Proper Containers for Squash Seedlings

Growing squash transplants in containers that are at least 5 inches deep is crucial. Their roots grow quick and large, needing more growing space than some plants. The containers or pots used must also contain drainage holes.

Filling and Planting the Containers

The planting container should be filled with a premium plant starting mixture. Adding dry potting mixture to containers followed by watering is not the best way to ensure the soil is moist throughout the containers. To ensure moist, not soggy soil, try these steps:

  • Fill a clean large bowl or bucket with premium plant starter mixture.
  • Add a little clean water at a time and thoroughly mix.
  • When moist, not soggy, add to planting containers filling to 1/4 inch of rim.

Once the containers are filled with the moist plant starting mixture, it is time to plant seeds. Simply, sow one or two seeds 3/4 inch deep into each container.

Providing the Proper Environment for Growth

Germination of squash seeds requires the proper temperature, oxygen, and water. Start squash seedlings indoors two to four weeks before the last frost. Grow in a room that is at least 70°F (21°C). Keep the soil moist, not soggy. Soggy soil can actually reduce the oxygen needed for germination.

Given the right amount of moisture and heat, the seeds will germinate in 10-14 days for most varieties of squash: some can germinate in less than a week. The newly emerged seedlings will need to be under grow lights about 15 hours per day if natural light is not adequate.

Preparing the Seedlings for Transplanting

Squash seedlings soon develop true leaves. At this point, start putting the seedlings outdoors on warm days. Expose the seedlings to more and more sunlight each day for about three days. The seedlings are ready to be planted outdoors if the air temperature is consistently 65°F (18°C) or higher. The soil temperature 2 inches below the surface should be at least 60°F (16°C).

Transplanting the Seedlings

Squash seedlings that have grown much more than a couple true leaves may experience transplant shock and even die. To help prevent this, remove seedlings only when the soil is moist. Gently push seedling container at the bottom, pushing the seedling out. Do not pull the plant out by the stem.

Dig holes in the prepared garden soil for the seedlings. The hole should be as deep as the seedling root ball is and twice as wide. Fill the hole up with surrounding soil and water.