Goldenrod, Tall - Solidago altissima
Solidago altissima, also known as Tall or Late Goldenrod, is a perenial wildflower native to Michigan and the U.P. Its unique feature is its shade tolerance. It thrives in light shade and makes a good forest-edge plant or for creating a soft-landing zone for insects overwintering beneath trees. Tall Goldenrod is also an excellent caterpillar host plant and late-season pollinator resource, and is better behaved than its infamous cousin, Canada Goldenrod (Solidago canadensis). Tall Goldenrod does spread by rhizome and will probably spread in a open garden with some enthusiasm. But in our experience, it is not paricularly agressive and is easily contained by surrounding vigerous plants. It prefers medium to medium-dry soil and full sun to part shade. Plant it as a drift, rather than a specimen plant.
Tall Goldenrod can reach 6 feet in prime conditions, but in other habitats it can be as small as 2 feet. It has a cheerful array of flowers in the late summer and fall which is quite variable in shape, from the classic goldenrod pyramid of horizontal flower stems, to a compact plume.
Another distinct visual feature of this goldenrod is its tendancy to get goldenrod galls. At least 15 species of insect house their larvae in the stems of this plant causing a round ball on the stem. This swelling of the plant stem is the winter home for the larvae, and rather than being a detriment, goldenrod galls are a positive. They add visual texture in the winter, after the leaves have dropped, and they serve as an important bird feeder to chickadees and downy woodpeckers. These and other birds will excavate the larvae in the galls throughout the winter. By planting Tall Goldenrod, you are planting your very own natural bird feeder!
In addition to being one of three goldenrod species which supports goldenrod galls, Tall Goldenrod, like all goldenrods, is a keystone species - meaning they host essential numbers of moth and butterfly caterpillars on their leaves. Those caterpillars fuel the ecosystem by feeding birds and other animals, or by producing the massive numbers of pollinators (moths) that are needed to feed everything from birds to bears to bats and other animals, as well as to pollinate and allow the plants to reproduce. Recent studies estimate that 50% of pollination is done by moths, including the pollination of fruit trees and garden crops. Moth caterpillars specialize - each species only eats certain types of plants. Goldenrods feed about 135 different species of caterpillar, far more than most flowers, so it is important to have lots of goldenrod species in your habitat. There are dozens of goldenrod species, each with a unique bloom time, shape, scent (some of them smell like honey), and relationship to moths, butterflies, and bees. Collect them all, and end the disparagement of this critically important plant.
Goldenrod is often wrongly accused of causing hay fever, or seasonal allergies. Most seasonal allergies are caused by ragweed, an unnoticeable green plant which is wind-pollinated and whose sole purpose in life is to fill the late-summer air with pollen. Goldenrod takes the blame for ragweed's crimes just because it is beautiful (noticeable) and happens to bloom at the same time. (I will also note that certain companies find it easier to vilify goldenrod in their commercials than to educate people on the appearance of ragweed. Don't fall for the marketing ploy.) However, goldenrod pollen is not in the air. Goldenrod is insect-pollinated. It has evolved elaborate measures to get its pollen to stick to pollinators. Goldenrod pollen does not blow around on the wind. Put the blame where it belongs. Feel free to give ragweed the side-eye while filling your garden with lovely, does-not-cause-seasonal-allergies goldenrod.