How to Start Seeds in a Greenhouse

Preparation

• 1

  Measure the amount of seed starting potting soil that you want to begin with into a bucket. Now turn the soil as you spray water in until the soil is just damp.

• 2

  Add lukewarm water to the potting soil. Work the water in until the soil begins getting wet.

• 3

  Pull handfuls from the bucket and squeeze them to remove any excess water. Some should drip out, but not a lot. If you are not seeing water drip when you squeeze, you might not have enough water in it. Spread it out evenly in your starting tray, just about one inch deep.

Planting the Seeds

• 4

  A good tool is an unsharpened pencil. Mark the side with the depth to plant. Poke holes in the potting soil to the depth you need to plant the seeds. Spacing depends on what is being planted, but an inch apart is a good starting point. Make the holes in rows and columns.

• 5

  Drop one seed into each hole. Once all the holes have a seed, gently press the hole closed with your finger.

• 6

  Cover the flat with plastic wrap or a plastic cover. If the type of seed needs warmer soil temperatures than the greenhouse can provide, place the tray on a warming mat and keep it plugged in until the seeds germinate. Check every few days to make sure the soil isn't drying out. Mist with the water bottle if it is.

• 7

  Remove the cover when the green shoots appear. Keep the soil moist over the next few days as the remaining seeds germinate. Seeds that require long germination periods may need the covers to remain in place longer.

Planting the Seedlings

• 8

  Prepare regular potting soil as before, in a bucket or tub and adding water until well dampened. Squeezing it should just barely produce a few drops. Fill plastic cells with soil until you have enough to handle all your seedlings.

• 9

  Begin transferring the seedlings to cells when they have grown one set of true leaves. Using a small spoon, carefully slice into the soil around a seedling, then lift it out with the spoon.

• 10

  Transfer the seedling to a plastic cell. With practice, you can pick up a seedling with the spoon, use the tip of the spoon to press a space into the soil and slide the seedling off at the same time. Gently press the soil back around the newly potted plant.

• 11

  Follow guidelines for the type of seedlings you have. Generally, place the cells into a plastic flat and fill it with an inch of water. Once per week, fill the cells with a weak mixture of liquid fertilizer. Include a root starter fertilizer once the plants begin to be established in the cells, usually in about one to two weeks.