A planting gel, sometimes called propagation gel, retains moisture around a germinating seed so it doesn't dry out during the the early growth stages. The gel simplifies planting small, difficult-to-handle seeds, such as carrots (Daucus carota). You can also pre-germinate the seeds in a moist paper towel before suspending them in the gel, which improves germination rates and allows you to start seeds early. Gels work well with most seed types, including annual flowers or vegetables like tomatoes (Solanum lycopersicum), or perennials like lupines (Lupinus spp,), hardy in U.S. Department of Agriculture plant hardiness zones 4 through 8.
Fill a saucepan with cold tap water. Add 1 tablespoon of cornstarch for every cup of water in the pan.
Stir the cornstarch into the water with a whisk until it's fully dissolved.
Bring the mixture to a boil over medium-high heat, stirring constantly so lumps don't form. Boil for one minute or until the cornstarch mixture develops a thick, gel-like consistency. Remove the mixture from the heat and continue to stir until it quits bubbling.
Fill a large bowl with ice. Set the saucepan on top of the ice to speed cooling. Allow the gel to cool to room temperature before using it.