Answer: I don't think there's anything wrong with your cosmos. They may be a different variety than those you purchased, or they may simply be too immature to bloom at the same time. Quite often, plants grown in greenhouses are given lots of fertilizer and are grown under ideal conditions. Those growing in a garden have to put up with the weather and cool evening temperatures which could retard their flower production abilitities. Give your plants a few more weeks of sunshine and warm weather and they should begin blooming their little heads off.
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