They are sun-loving plants and ideally should be planted where they will receive direct sun at least six hours a day. They will also survive if they just get afternoon sun or in a very-high light situation, but they may not bloom as well and may be more susceptible to disease problems. Zinnias are native to Mexico and once they are established, they are drought-tolerant plants. Keep them evenly moist while they are growing rapidly early in the season so they develop an extensive root system. As summer progresses, they become more and more drought-tolerant.
Zinnias grow in almost any soil as long as it is well-drained.
Their drought-tolerance makes them a good choice for sandy soils. Zinnias aren't heavy feeders. All older zinnias are suitable for cutting. In fact, one variety is called 'Cut and Come Again'. The old standard for a large flower with a long stem is called 'State Fair' and there are lots of newer improved varieties.