The good thing about pinching the dahlias out is you get multiple growths from the same point which means more flowers. If you just let the original growth keep heading upwards, you tend to get quite a lanky, unstable plant, which will flop over (and possibly snap) in a gentle breeze. This isn't so important in the shorter varieties but if you do leave it, stake each stem well.
I think people who show dahlias leave them as tall single stems but if you are like most of us and want flowers you might need to be brave and give pinching a go.
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I think people who show dahlias leave them as tall single stems but if you are like most of us and want flowers you might need to be brave and give pinching a go.