Answer: Luckily for you, the annual cosmos is a very quick growing plant and is best started a bit late because it prefers warm soil and likes hot weather. Depending on growing conditions and the weather of course, you could have blooms within about six weeks from seed. Cosmos need full sun and do better on a lean soil; a rich soil causes them to make foliage rather than blooms. The blooms will continue long into the fall, so there is still time to start them. In my experience they all take approximately the same amount of time, so select the size and color you like best!
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