The older varieties are more upright and work well toward the back of borders. The newer varieties are more compact and tend to grow almost as wide as tall. They can be used in containers and in the front of borders. 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.