Sanvitalia is a great annual for humid, hot summers. Sanvitalia are very compact plants that grow, at the most, to about 16 inches high. Sanvitalia makes the perfect edging alongside sidewalks. It's also perfect for hanging baskets and rock gardens. Its 1-inch wide flowers, which resemble zinnias, bloom from mid-summer until the first frost. A healthy sanvitalia plant can spread to about 2 feet wide.
Sanvitalia plants tend to thrive in sunny locales with well drained, loose soil. For the best results, you want to seed outdoors as soon as the soil is warm enough. However, the seeds can be started indoors if you want to see color early. It is best to start sanvitalia plants in peat pots, since they are resistant to transplanting. Since the seeds need light to germinate, they should be left uncovered. For the best results, plant the seeds up to 14 inches away from one another.
Sanvitalia is often referred to as a creeping zinnia, although it is not a true zinnia. Although its flowers are not very large, they are so abundant that they oftentimes nearly obscure the foliage. If you are going to plant them indoors, it's best to sew them in pots or trays of seed compost. Keep them at a gentle warmth of about 65 to 70 degrees, and make sure to keep them moist, but not wet. The kitchen windowsill is the prime location for them. Remove dead flowers to prolong the flowering process.