Nasturtiums (Tropaeolum majus) are annual flowering plants native to South America. They grow in both climbing and bushy varieties. Nasturtiums are fast-growing plants that don't transplant well, so plant the seeds directly into the garden. Choose a spot in the garden where nothing else grows, whether it is due to poor soil or not enough moisture, and the nasturtium will do well there. Plant nasturtium seeds in the spring in USDA hardiness zones 4 to 8, and in winter in zones 9 to 11.
Break up the soil in the nasturtium bed by digging it up to a depth of 6 inches. Remove any roots, weeds, rocks and other debris.
Add a 2-inch layer of sand to the bed and use a gardening fork or shovel to mix it to a depth of 6 inches. Rake the bed until it is level.
Plant the nasturtium seeds 1/2 inch deep and 12 inches apart. Lightly pat the soil over the seeds.
Water the area carefully, to a depth of 2 inches. Be careful not to wash away the seeds. Keep the soil moist until the nasturtium seeds germinate, which should occur within a week to 10 days.