Answer with explanation:
The genetic composition of the plant defines its structure, they are summer-blooming plants because they need sun and moist steady soil. This plants have adapted to warm temperatures and are not prepared to resist cold, the seeds of the plant are intolerant to cold as well, so this plants better grow in summer or warm climates places, the season the sunflower is planted will affect its development, furthermore, the soil needs to be steady to resist the weight of the plant ones it grows otherwise the plant will die short after blooming, this is the reason the plants grow in American summer, It is sunny, warm and has a steady soil.