Buy healthy, green plants with no signs of wilting or disease. Plants should be stocky with plenty of leaves. It's a plus if they don't have any flowers since that means that they'll divert their early energy into root development, creating healthier plants in the long run.
Choose a spot with full sun to very light shade and average, well-drained soil. If you're growing nemesia over the winter, plant it where it will receive protection from north and west winds.
Plant 4- to 10-inches apart, depending on the variety. Check the label for directions.
Keep soil evenly moist.
Fertilize once or twice during the growing season.
Pinch or trim off spent flowers to promote bushier plants and flowering.
Discard plants once they're felled by heavy frost or get ratty at season's end.