Time for a nature hunt! Look for some moss, pinecones or small ferns to place in your jar. You want to keep about 1 plant per 1-inch diameter, if possible. Generally, plant your largest plant first so you leave enough space. Sprinkle a couple pinches of seeds over the top of the soil. Finish with any small extras, if you decide to use them. Spray the top with water to make the potting soil very moist. Do not pour water over your soil.