How to Start Seeds in a Greenhouse


A greenhouse is a great way to get a head start on your gardening, especially in the cold months of winter. Starting seeds in a greenhouse will give your plants a chance to flower and bear fruit faster than those set out as seed. You also can speed up the sprouting process if need be. Greenhouses provide a consistent environment and protect fragile seeds from the dangers of being planted outdoors, like foraging animals and bad weather.

Step 1

Wrap seeds in a damp paper towel, and place them inside a plastic bag for a few days to prepare them for planting. Or soak them in a bowl of warm water for three hours.

Step 2

Fill your seed trays with potting soil.

Step 3

Dig a small hole in each tray section for seeds. Each hole should be about 1 to 2 inches deep and 2 inches wide.

Step 4

Place the seeds in the holes, and cover them with soil. Place one seed per hole if they are large seeds, such as melons. Place 3 to 4 seeds per hole if they are small seeds, such as marigolds.

Step 5

Water your seed trays with warm water. Keep the soil around the seeds moist at all times.

Step 6

Place toothpicks in the soil around the seeds. Drape clear plastic over the seed trays. This will keep the soil warm and moist.

Step 7

Remove the plastic once the sprouts poke out of the soil.

Step 8

Allow the seedlings to grow until they are large enough to be planted outside. This will be different for every type of plant.

Tips and Warnings

  • Do not overwater your seedlings, or they might mold and die.

Things You'll Need

  • Potting soil
  • Seed trays
  • Clear plastic wrap
  • Toothpicks


  • Seed Starting Basics
  • Starting Seeds in the Greenhouse

Who Can Help

  • Greenhouses and Cold Frames Hints and Tips
Keywords: starting seeds in a greenhouse, start seeds in a greenhouse, planting garden seeds

About this Author

Hollan Johnson is a freelance writer for many online publications including Garden Guides and eHow. She is also a contributing editor for Brighthub. She has been writing freelance for over a year and her focus' are travel, gardening, sewing, and Mac computers. Prior to freelance writing, Hollan taught English in Japan. She has a B.A. in linguistics from the University of Las Vegas, Nevada.