Many plants will grow to different heights depending on where they are planted. This is one of them. Bees really love this plant as do moths and butterflies. The flowers are white spires in a candelabra formation. Sometimes the flowers and have a pink or purplish blush to them. The leaves whorl around the stem and are dark green, rounded at the base and pointed at the ends. 
 
The plant grows from 2 to 6 feet tall. It will reach its tallest height in full sun and moist soil. In the shade and drier soil, it will be shorter. No matter what height it makes a strong statement in the garden. From this you can infer that it does like full sun and moist soil best. It tends to flop in full shade so I would not put it there although it will grow there.
 
Great companions are wingstem, Ironweed, Joe pye weed, boneset, grasses, marsh fern, for a groundcover try golden groundsel. Remember when adding white flowers to your gardens it makes the other colors pop. Generally, in New York it starts flowering in late July.