While I don’t have any golden rod in my garden it is all along the trails of The Woodlands, blooming for most of October.
Around here goldenrod grows to about 6′ in height, further north it tops out at about 4′ in height. IN a garden it will grow taller and wider than in the wild, so leave it some room.
Plant in full sun to part shade. My books say to plant it in well drained areas. Here it grows in damp areas, so I expect it isn’t picky about that.
Don’t fertilize, it is used to growing in poor soils and quite happy doing so.
Cut the plants back after blooming if you wish.
Propagate by division after blooming or in early spring. Transplants do best if planted early spring. Goldenrod will reseed and spread by root.
These are excellent flowers for cutting and drying.
Loves water, not very drought tolerant.
Needle rust – small white blisters appear on plant. This is caused by a fungus, use your favorite fungicide.
Goldenrod has taken the blame for many a hayfever, but it’s not the goldenrod that causes hayfever. The pollen is very heavy and does not travel far in the wind. Ragweed blooms at the same time and its pollen does easily travel.