Cut open a kumquat fruit and remove the seeds.
Mix equal amounts of potting soil and sand for a potting medium.
Cut drinking cups to about 3 inches tall and punch holes in the bottom for drainage. Fill the cups with the planting medium.
Plant the seeds while they are fresh and moist. Insert one seed approximately 1/2-inch deep in each cup. Cover the seed with potting medium.
Water the seeds lightly. Place each cup in a medium-size resealable plastic bag to keep the seeds moist.
Place the cups in the sun to encourage germination. Watch for growth in two to three weeks. Spray the seeds with water occasionally to keep the soil damp but not wet.
Remove the plastic bags after the seeds have sprouted. Continue to water regularly.
Transplant your seedlings once they have grown to several inches. Plant them in larger pots or fertile, prepared soil in your garden.