|soil mix for starting seeds in greenhouse|
|Commercial growers may use a variety of mixes based on what crops they intend to start, but at home most gardeners have good luck with the sterile, soil-less, seed starter mixes. These are sold at garden centers along with other supplies such as cell packs and the seeds themselves. These bagged mixes are very clean (important to avoid fungal problems when seed starting), and are usually based on milled sphagnum peat moss mixed along with perlite and/or vermiculite. I have had good experience with products such as "JiffyMix" formulated especially for seeds, and I have also had good results using a general purpose soilless mix such as "Pro-Mix".
In my experience the secret is in preparing the mix so it is just slightly moist (like a wrung out sponge), planting the seeds, setting the container in a bright location but out of direct sun, then enclosing the container with clear plastic wrap so that the humidity and soil moisture stay constant until germination begins. This method eliminates the need for frequent watering and but yet helps keep the soil evenly moist -- seeds will die if allowed to dry out, they can also drown or rot if overwatered. Good luck with your seed starting!