Answer: Coreopsis tends to get a bit gangly; it can be trimmed back immediately after flowering to neaten it and encourage additional blooms. You can also try to stake it or tie it in gently by putting stakes around the perimeter and then tying string around the perimeter and then criss crossing within the ring like a spider web. If yo do this early in the season then the plant should grow up through this and be supported. Also be sure it is not over fertilized and that it is in full sunlight -- either of these factors can cause it to flop even more than it normally does.
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