Buy healthy, green plants with no signs of wilting or disease. Plants should be stocky with plenty of leaves. It's actually a plus if they don't have any flowers on them so that they'll divert their early energy into root development rather than flowering.
Plant monkey flower seedlings outdoors in spring after your region's last annual frost date. Choose a site that has light shade and isn't subject to drying out.
Position plants 6 to 12 inches apart and water in well.
Keep well watered.
Fertilize once or twice during the growing season if desired. Or work in a spadeful or two of compost at planting time.
Pull up and discard plants in autumn after felled by frost.