Blue-stemmed goldenrod, Solidago caesia
 
Blue-stemmed goldenrod is a delicate, elegant plant, also called wreath goldenrod. It attracts metallic blue and shimmering green bees in the shade. It blooms in the fall and is listed as rare in the wild.
 
Ecology:
Blue-stemmed goldenrod delights bees, butterflies, wasps, skippers, beetles and flies with its rich pollen and nectar and birds with caterpillars and insects in spring and its seeds all winter long. It is an important late-season nectar plant for next year's bumblebee queens to build fat reserves to overwinter and for monarch butterflies to fuel up for their migration over Lake Erie to Mexico.
As with all goldenrods, it supports an unsurpassed number of pollen specialist bees with its rich, big, sticky pollen. One-third of Ontario's bees rely on a very specific plant or plant family to collect specific pollen to provision their nests so their future larvae can feed on it and produce the next generation.
Goldenrod is also unsurpassed in providing food for the caterpillars as a host plant for over 100 moth species. This is important because they are the non-negotiable food source for breeding birds. Caterpillars are the very reason birds migrate to Canada in the first place.
So, make room for some goldenrod in your garden. Stiff goldenrod and upland white goldenrod are non-spreading goldenrods for sun, and blue-stem goldenrod and zigzag goldenrod are ideal for shaded areas. Be careful not to plant prolific rhizomatous species like Canada goldenrod; they can quickly take over small spaces.
 
Growing conditions:
Blue-stemmed goldenrod is found on forest edges and in deciduous upland forests and therefore prefers soil with high organic matter. To increase organic matter in your garden, leave the leaves and chop-and-drop stems right in place. It can grow in full shade, but grows much bigger, with more blooms, and is truly stunning in partial or dappled shade or even almost full sun. It is clumping and does not spread.