How to Start Plants from Seeds at Home

Buy a bag of seed-starter mix or prepare your own. You'll find different recipes for a light soilless mix to get your seeds started. The University of Missouri suggests 4 quarts of vermiculite, 4 quarts of peat moss, 1 tbsp. of superphosphate and 2 tbsp. of pulverized limestone blended uniformly.

Add the seed-starter mix to a nursery flat, leaving 3/4 inch of space between the soil surface and the container's rim. If you decide to reuse a planter, wash it and dip it in a solution of one part bleach and nine parts water to sterilize it. Then, fill it with potting mix.

Irrigate the growing medium before sowing the seeds. Add water until excess runs out of the flat's drainage holes and the surface is uniformly moist.

Sow the seeds on the soil surface. Separate different plant varieties or species by rows 2 inches apart. Add enough seed-starter mix over the seeds to bury them at the recommended depth for germination. Onion seeds, for example, should be ½ inch below the soil surface. But cover cucumbers with a 1-inch-deep layer of soil. As a general rule, plant seeds at a depth twice their diameter. A sifter helps you to distribute the soil evenly over the seeds.

Fill a spray bottle with water and use it to moisten the layer of soil covering the seeds.

Cover the flat with a piece of clear plastic film to conserve heat and moisture for the seeds. Place it in a well-lit location but away from direct sun. In general, keep seeds at 65 to 75 degrees Fahrenheit. Cool-season crops such as cabbage and broccoli germinate at 55 degrees Fahrenheit. Plant them in flats separate from warm-season crops.

Check your seeds every day for signs of germination. As soon as a seedling sprouts, remove the plastic film and move it to bright but indirect sunlight. Put the young plants on the ground when they reach the ideal size for transplanting. Peppers are ready to go out eight weeks after sowing, for instance.