Goldenrods - the yellow fall flower

Mary Ann Ryan
Adams County Master Gardener

(8/2) Goldenrod – what do you think of when you hear that word? Often just the word could make some people sneeze, or at least associate sneezing with this plant. However, ragweed happens to be the culprit of our allergies, not goldenrod. Ragweed blooms about the same time as goldenrod and is not at all showy. The pollen on its green flowers is spread easily by wind, making it easily accessible to all those that are allergic to fall pollen. Since this two plants bloom at the same time, and the goldenrod is the plant we can easily see because of its showy golden yellow flowers, very often the goldenrod gets a bad rap simply because it’s blooming when we begin to sneeze.

Knowing that this plant is not our "sneeze machine" can allow us a bit more of an open mind to the benefits of the goldenrod. Not only does it give us great color from late July through October, depending on the species, but it is a great plant for our beneficial insects. Bees, butterflies and many other insects depend on these flowers when little else is blooming for nectar. Having goldenrod in your garden will encourage bees and butterflies to either remain in your garden for a bit longer or drop by for a visit as they pass through.

Generally, solidago have little insect and disease issues. Some may get stem galls, which don’t harm the plant, but in a garden it may cause concern because it looks a bit funny. It is a swelling of the stem caused by a parasitic fly. If considered an eye sore, the gall can just be cut out and disposed of in the trash. Some species can also get powdery mildew if in too much shade or the soil is too wet. In either case, insects and diseases are tolerated by this genus of plants, making most of the species a good selection for the perennial garden.

Solidagos have yellow flowers, bright and showy. Most will tolerate many soil types and like full sun. As we look at some of the different species, I’ll point out the differences in the soil and sun needs.

In order to have the longest bloom time from this genera, different species of the goldenrod will be necessary. Although each species will have peak bloom for three to four weeks, they do not bloom from July through October. Let’s take a look at some of the common species that can be found in this part of the country.

Beginning with the earliest of the bloomers, Solidago juncea blooms in July. It likes well-drained soils and full sun. As it does tend to spread; division is recommended every three years or so. Like many of the species, this one likes full sun and well-drained soils. It tolerates very dry conditions and rocky areas.

Solidago speciosa, showy goldenrod, is a late blooming plant. It reached 3 feet tall and wide, so give it some space in the garden. The flower spike can be as long as a foot! It’s a very upright plant, not arching like some of the goldenrods.

Solidago odora, as the name suggests, has a scent of anise, and is commonly called scented goldenrod or anise goldenrod. This one typically blooms in August and can manage a little bit of shade. It’s naturally found in open woods. It gets about 2 feet tall and wide, so not a huge one, and it is very well behaved.

I have a few favorite species of goldenrods, and this one in on my list. A lower, spreading, ground cover-like goldenrod is zig zag goldenrod, Solidago flexicaulis. Growing best in the shade, unlike most goldenrods, it has small clumps of yellow flowers that "zig zag" down the stem. It gets about 1’ – 2’ tall and is a more dainty show than most of the other goldenrods. This flowers in August through early September.

Solidago sphacelata ‘Golden Fleece’ was discovered in 1985 and introduced in 1989 by Mt. Cuba Center. This selection of S. sphacelata is dwarf, looking good in the front of a fall perennial border. It is one of the shortest goldenrods, only getting one foot tall. The straight species, Solidago sphacelata, will reach 2’-3’ tall and is one of the later bloomers – starting in mid-September. I would suggest planting the selection in your garden for consistent size and control.

Fireworks goldenrod, Solidago rugosa ‘Fireworks’ tolerates moist soils, unlike many of the other species of goldenrod. It also does well is part shade to full sun.The spray of flowers gives it it’s name: fireworks. This is a later season bloomer, typically in September. The straight species, Solidago rugosa is unpredictable in size, however, ‘Fireworks’ will consistently reach about 2’ tall and is very well behaved. It, too, is on my list of favorite goldenrods.

Blue stemmed goldenrod, Solidago caesia, prefers part shade, unlike many of the other species. As the name infers, the stems have a blue color to them, depending on how the light hits it. I first saw this plant in a fellow Master Gardener’s garden. She has it planted in the shade in both a container as well as in the ground. A very sweet plant, the flowers are in small clusters up and down the arching stem. It will reach 2’-3’ tall, but it does arch, so in the garden you may see it more horizontal and opposed to upright. This is one of my favorite goldenrods, as it is so unlike any of the others.

Solidago rigida, stiff goldenrod, is a late summer bloomer. Unlike typical goldenrods, the golden yellow flowers are on top of the tall stems in a cluster. Very tolerant of poor soils, this goldenrod will reach 3’ – 5’ tall! Certainly one to check out for the background of the garden.

One to avoid is Solidago canadensis, Canada goldenrod. This particular species is very aggressive and very difficult to control in a garden or meadow. Once it takes hold, it really takes over. We have trouble with this one in our meadow, and it will choke out other native species of plants. Although it is very showy, pull this one out of the garden when it makes its appearance.

Goldenrods pair nicely with many of our native perennials like ironweed and asters in sunny gardens and meadows. Mixing the shade goldenrods with plants like ragwort (Packera aurea), coral bells {Heuchera villosa) and Tiarella make great combinations. Using these plants in containers for late summer and fall color is a great option too. They do great in meadows, perennial borders, and cutting gardens.

Goldenrods have a bad reputation. Most are manageable, provide that needed late summer, early fall nectar and food source, and provide lots of color in the fall garden. Try some and see how you like them in your garden!

Read Marti Young's: Goldenrod for Fall Color

Read other fall related gardening articles

Read other articles on ecological gardening & native plants

Read other articles by Mary Ann Ryan