How to Plant in a Greenhouse


For many gardeners, a hobby greenhouse can create a bubble of warmth and greenery in the dead of winter. In spring, a greenhouse is a good way to start the growing season early by nurturing seeds into seedlings. These tender seedlings can be moved outdoors and placed in the garden just when the soil is ready for planting. But if you want those plants to thrive, you must give them the right start in your greenhouse.

Step 1

Fill a seedling tray with peat moss. Water with a watering can so that the peat moss becomes as damp as a wrung-out sponge.

Step 2

Create a planting pocket in your seedling tray by pushing aside peat moss with a popsicle stick. Place the seed into the planting pocket and push the peat moss over the top of the seed. In general, seeds should be planted twice as deep as the seed is tall. Refer to the planting instructions on the back of each seed packet for more specific instructions.

Step 3

Cover the seedling flats with a plastic bag or plastic dome to hold in moisture that the seedlings need to germinate. Place the flats where they receive at least six hours of indirect sunlight daily. Remove the plastic cover when the seedlings germinate.

Step 4

Place the flats in a tray filled with water when the soil becomes dry. Water will wick up from the bottom of the tray. Check the flats daily to determine if they need watering.

Step 5

Fill peat pots with peat moss for transplanting seedlings when they outgrow seedling flats.

Step 6

Create a planting pocket in the center of the peat pots that is slightly larger than the root ball of the seedling.

Step 7

Remove the seedling from the tray gently by pushing on the bottom of the individual cell of the seedling tray. The seedling and root ball should pop out. Place the root ball into the planting tray and cover with peat moss. Water well.

Step 8

Move peat pots outdoors during daylight hours to harden them off in preparation for transplanting. Continue to leave them in the greenhouse at night until the day of transplanting.

Things You'll Need

  • Greenhouse
  • Seedling flats
  • Seed packets
  • Watering tray
  • Garden trowel
  • Peat moss
  • Popsicle sticks
  • Watering can
  • Plant mister
  • Peat pots


  • University of Alabama Extension: Hobby Greenhouse Operations and Practices
  • Washington State University: Seed-Starting Techniques and Best Practices
  • University of Massachusets Amherst: Greenhouse Crops and Floriculture

Who Can Help

  • University of Minnesota Extension: Starting Seeds Indoors
Keywords: how to start seeds in a greenhouse, growing plants in a greenhouse, Early greenhouse planting

About this Author

Tracy S. Morris has been a freelance writer since 2000. She has published two novels and numerous online articles. Her work has appeared in national magazines and newspapers, including "Ferrets," "CatFancy," "Lexington Herald Leader" and "The Tulsa World."