Solidago

( sol - id - DAY - goh )

At-A-Glance Information

Commonly called Goldenrod, this genus of perennial flowering plants needs full sun to light shade and moderate water. Their flowers will attract birds and butterflies to your yard. They are native to the Eastern regions of the United States, and bloom from the middle of summer through fall. They are so commonly encountered in their native range that the Goldenrod is the official state flower of Kentucky. Flowers form in branched clusters and are yellow; leaves are green. They are easy-care plants and thrive in semi-poor soils. Goldenrod is perfect for informal border plantings or for naturalizing in meadow landscapes.

Solidago Species and Varietals

The genus Solidago is a member of the plant family Asteraceae and includes between 100 and 120 species. Goldenrod grows best in zones 1-11 and 14-24. To find your zone, click here: Zone Map.

Solidago albopilosa (Whitehair Goldenrod)
This rare species is endemic to Kentucky, and produces one or more erect stems from a woody base. It reaches between 12 to 20 inches (maximum 40 inches) tall and is covered in white hairs. Flowers bloom in clusters in groups of up to 30 and are golden yellow. They bloom from September to November in their native range.

Solidago bicolor (White Goldenrod, Silverrod)
These plants are native to eastern North America, and prefer to grow in sandy or rocky soils. They are typically found growing along roadsides or in other areas with disturbed soils. Flowering stems are thin and wiry, and flowers are white, unlike most species in the genus. The flower heads are found in leaf axils.

Solidago californica (California Goldenrod)
These wildflowers are native to many types of habitats in western North America, and reach 5 feet tall when mature. Leaves are green and lance-shaped, and flowers are narrow, comprised of many golden-yellow flowers.

Solidago canadensis (Canada Goldenrod, Canadian Goldenrod)
These herbaceous perennial plants often form colonies of upright shrubby plants with green foliage and yellow flowers that bloom towards stem tips. They are native to northeastern and north-central North America, and are considered invasive in Europe and Asia. This species is commonly grown as a garden ornamental in native, pollinator, and cottage or informal gardens.

Solidago curtisii (Curtis' Goldenrod, Mountain Decumbent Goldenrod)
This North American species forms a 40-inch tall perennial herbaceous plant with green foliage. Stems are narrow, wiry, and dark purple. Flowers bloom in small clusters in leaf axils and are yellow.

Solidago virgaurea (European Goldenrod, Woundwort)
These plants are widespread across Europe and North Africa as well as Asia. It is grown as a garden ornamental and has many subspecies and cultivars. In the fifteenth and sixteenth centuries, they were used to heal wounds due to its astringent and antiseptic properties.

Solidago gigantea (Tall Goldenrod, Giant Goldenrod)
This species is the state flower of Nebraska, and forms clumps of upright stems with green foliage. Flowers are yellow, and bloom in drooping arrays of many flower heads (up to several hundred). Plants in this species grow in a wide variety of habitats, as long as soil is at least seasonally moist.

Solidago Hybrid Varietals
These cultivars have been bred to do well in garden settings, and are typically a bit smaller and bushy than the species in the genus. These are great choices for garden ornamentals, and will attract pollinators to the landscape.

'Crown of Rays'
Reaches 2-3 feet tall and 1-2 feet wide; clusters are flat.

'Golden Baby'
To 2 feet tall and 1.5 feet wide. Plumelike flower clusters.

'Goldenmosa'
Grows to 2.5 feet tall and 1.5 feet wide, with large clusters of flowers.

'Little Lemon'
10-12 inches tall and 15 inches wide, with a long flowering season. Perfect for containers.

Solidago ptarmicoides (Prairie Goldenrod, White Flat-Top Goldenrod, Upland White Aster, Upland White Solidago, Upland White Goldenrod, Sneezewort Goldenrod)
These North American perennials are native to central and eastern Canada and parts of the United States. Flowers are white to cream-colored, and are arranged in a flat-topped inflorescence. Stiff leaves are narrow. These plants prefer dry, sandy soils and grassy meadow landscapes.

Solidago rugosa 'Fireworks' (Wrinkleleaf Goldenrod, Rough-Stemmed Goldenrod)
This variety reaches 3-4 feet tall and 2-3 feet wide, with flower spikes that resemble shoots of fireworks. The species is native to North America, and is usually found in wet habitats. Flowers are yellow.

Solidago sphacelata 'Golden Fleece' (False Goldenrod, Autumn Goldenrod)
Reaches 1.5 feet tall and 2 feet wide, with profuse sprays of yellow flowers. It is great as a groundcover, and can create a solid mat in about a years' time. Set 15 inches apart for best groundcover coverage.

Caring for solidago

Solidago, or Goldenrod, can be grown from seed direct-sown or started indoors and planted out, and it can also be purchased as a specimen from reputable nurseries. They are best planted out in springtime. Choose a space in the landscape that receives full sun to partial shade. Ideally, these plants like to get between 6 and 8 hours of sun every day for optimal flowering, but they do appreciate shade during the warmest hours of the day (especially in hot climates). If they are planted in a space that is too shaded, they will not bloom as profusely. Soil should be well-draining, moderately fertile, and have a pH of between 5.5 and 7.5 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing, but ensure that soil is not too rich, as this causes plants to flop over. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. At maturity, Goldenrod is drought tolerant and can get by on rainwater alone for most of the year, with supplemental irrigations during extended periods of dry weather.

Fertilizing is not necessary for Goldenrod plants; they actually perform a little better in leaner soils. However, if local soils are particularly poor, fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Take care to not over-fertilize Goldenrod plants, as they have a tendency to become floppy and less floriferous. Deadhead spent flower spikes (unless you will be collecting seeds for propagation). This will discourage re-seeding, encourage more blooms to pop, and clean up the look of the plant. Remove dead, damaged, diseased, or unattractive foliage at any time during the growing season. Divide Solidago plants when blooming or overall performance declines; typically every 3-4 years will suffice. For instructions on how to successfully divide Solidago plants, see the Propagation section below.

Propagation

Solidago, or Goldenrod, can be propagated by division or seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant, especially if you are propagating a hybrid cultivar. To propagate your Goldenrod plant, follow the instructions below:

Propagating Solidago by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Harvest your seeds. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 2-6 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Solidago by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
In early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 3-4 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new plant.

Propagating Solidago by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your gloved fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section attached.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.