How to Start Plant Seeds With Watering Trays


The use of watering trays enables gardeners to plant seeds and not worry about overdrying. The potting soil absorbs the water in the trays to promote seed germination and seedling growth. Soil is less likely to become dry while seeds germinate under grow lights. The process to plant seeds with watering trays is simple enough for novice gardeners to use.

Step 1

Insert the tip of the scissors into the bottom of the first cup. Turn the scissors clockwise four times to create a small drainage hole. Remove the scissors. Repeat with each of the six drinking cups.

Step 2

Write the seed name on the side of each drinking cup with a permanent marker. This helps later to identify the seedlings.

Step 3

Add starter potting soil mixture to the drinking cups until they are half full. Check the potting soil bag label and make sure it is labeled as starter potting soil. This soil will have additional nutrients for successful seed germination and seedling growth.

Step 4

Insert the handle of a teaspoon into the center of the soil in the first cup. Wiggle the handle back and forth to create a hole 1 inch deep. Remove the teaspoon and repeat with all six cups.

Step 5

Deposit one seed into the hole of the first cup. Cover the top of the seed with a small amount of potting soil. Repeat with each cup.

Step 6

Fill half of the tray with water. Set each cup into the tray. The cups absorb the water from the tray through the drainage hole created in the previous step.

Step 7

Allow the cups to sit in the tray for two hours. Refill the tray with water to reach the half full level.

Step 8

Place the watering tray with the seed cups under a plant grow light. Position the light 6 inches above the surface of the cups. Adjust the light when the seeds germinate and seedlings emerge.

Step 9

Add water to the trays every fourth day to keep the soil wet for growing seeds and seedlings. Allow trays to completely to dry out the several days prior to transplanting seedlings outdoors.

Tips and Warnings

  • Never add fertilizer to the watering tray to avoid burning seedling roots.

Things You'll Need

  • Scissors
  • 6 small, plastic drinking cups
  • Permanent marker
  • Starter potting soil mixture
  • Teaspoon
  • Seeds
  • Plant grow light
  • Watering tray

Who Can Help

  • Garden Helper: How to Grow Plants with New Seeds
Keywords: seed watering trays, start plant seeds, plant seeds

About this Author

Lisha Smith writes for several blogs and has freelanced for six years. She has a Bachelor of Arts from UNC-Greensboro in psychology. Smith has self-published several books. Her areas of experience include gardening, cooking, home improvement, pets and mental health.