This is Solidago canadensis, commonly known as Goldenrod. It is an herbaceous perennial which is has native to Canada. The flower spikes are packed with yellow daisy-like flowers extending from horizontal stalks forming a cone shape.

Alternate narrow leaves frame the yellow flowers and the rhizomes anchor the plant in-place, enabling fast propagation making it an invasive plant.

Although not all is bad, this plant attracts many insects providing food in the later seasons before winter (August-October). To grow this plant responsibly one should cut off the seed heads and dispose of them to stop the plant spreading from your garden. I personally love the texture and height of this plant, it flows in the wind looking wonderful in the back of borders.