Goldenrod (Solidago) is a source of mild debate in the plant world. Some view it as a type of wildflower while others only see it as an invasive weed. There are more than 100 species of this herbaceous perennial. Generally speaking, goldenrod plants are tall and slim with fluffy golden flower spikes. They're attractive when they're in bloom in the late summer to fall, but otherwise the medium green foliage has a fairly unremarkable appearance. Goldenrod can be planted in the fall or spring. And true to its reputation as a weed it has a rapid growth rate and is an aggressive spreader. The plant will reach its full size in just a couple of months. Mature plants can spread via reseeding and underground rhizomes, outcompeting other plants in the garden.
|Plant Type||Herbaceous perennial flower|
|Mature Size||1.5 to 5 feet tall on average|
|Sun Exposure||Full sun|
|Soil Type||Average, medium moisture, well-draining|
|Soil pH||5.5 to 7.5|
|Bloom Time||Late summer to fall|
|Hardiness Zones||3 to 9|
|Native Area||North America|
Goldenrod is widely known as a plant that attracts butterflies, making it the perfect addition to any butterfly garden. It also attracts a number of other insects, including bees. In general, goldenrod species require very little maintenance. They rarely have pest or disease problems, and they can tolerate a variety of growing conditions. You might have to stake the taller varieties, so the plants don't flop over. You also can lightly prune them back in the early summer to promote bushier, more compact growth.
Most of the maintenance comes from preventing goldenrod plants from spreading where you don't want them. A simple solution is choosing to grow your plants in pots or in a garden bed with barriers to contain the underground spread. Another way to control the spread is to transplant your goldenrod often, at least every two to three years, so it doesn't have the chance to fully establish its roots. Plus, you should cut off the spent flower heads promptly to stop them from spreading their seeds if you don't want new plants to pop up. Otherwise, you can leave the flower heads on to serve as food for wildlife.
Goldenrod craves full sun for optimal flowering. The plant will tolerate a bit of shade, though this can minimize its blooms.
Goldenrod is not overly picky about its soil, as long as there is good drainage. It can even tolerate sandy, rocky, and clay soils. Soil that is very rich can cause the plant to get leggy and potentially flop over.
Water new goldenrod plants weekly to maintain moderately moist (but not soggy) soil. Mature goldenrod plants have good drought tolerance and rarely need supplemental watering unless you have a long stretch without rainfall.
Temperature and Humidity
Goldenrod thrives in the various temperatures throughout its growing zones, and it does not have specific humidity requirements. Frost will cause the plant to die back into the ground for the winter.
Fertilizing goldenrod is typically not necessary, as the plants can grow in lean soil conditions. However, if you have very poor soil or wish to give your plants a boost to increase their height, you can add a layer of compost in the spring.
How to Grow Goldenrod From Seed
Goldenrod is not widely available as seedlings due to its invasive nature, but growing the plant from seed is easy. After the danger of frost has passed spread the seed onto moist garden soil, taking care only to cover areas where you want goldenrod to sprout. Keep the soil evenly moist until sprouts appear, and then let the area dry out in between waterings. You also can start seeds indoors roughly six to eight weeks before your last projected frost date and transplant the seedlings outdoors once the weather has warmed.
The many goldenrod species vary somewhat in size and appearance. Some popular varieties include:
- Zigzag goldenrod (Solidago flexicaulis): The origin of this plant's common name lies in the fact that its stem actually grows in a zigzag pattern. The species reaches around 1 to 3 feet tall.
- Old field goldenrod (Solidago nemoralis): This plant is on the shorter side compared to other goldenrod species, only reaching between 6 inches and 2 feet tall. Its flower heads are more cylindrical than other species, as well.
- Bog goldenrod (Solidago uliginosa): As its common name suggests, this plant performs well in areas with wet soil, though it still prefers good drainage. It grows between 2 and 5 feet tall.
- Seaside goldenrod (Solidago sempervirens): This species grows by the seashore, as it's a salt-tolerant plant. Its height varies greatly—between 1 and 8 feet tall—depending on growing conditions.
- White goldenrod (Solidago bicolor): This plant is noteworthy simply because it does not display the typical yellow goldenrod blooms. Instead, it features white blooms.