Most flowers that require sun to part shade do well in a garden that receives intense afternoon sun. While flowers that require shade to partial shade are likely to wither and die in the hot afternoon sun, those that can tolerate full sun, such as black-eyed Susans and snapdragons, do just fine when properly cared for in a location receiving afternoon sun.
Marigolds and Lenten roses also both produce color blooms and perform well when planted in a location that receives afternoon sun. If the plants receive only afternoon sun and not full sun, their flowering schedule may differ from similar flowers planted in the full sun.
Hybrid zinnias, Chinese hibiscus plants, variegated false holly shrubs, alyssums, bergenias, foxgloves and daylilies all produce impressive blooms when planted in the afternoon sun. Because the afternoon sun is the most intense of the day, soil dries out quicker in areas that receive afternoon sun than in locations that have partial shade. Water these flowers regularly to produce regular flowering. Ensure that the soil pH is sufficient for the plants. Depending on how much moisture the plant needs, amend soil with sand or compost to improve drainage, or add peat moss to retain more water.