Solidago, Goldenrod: planting, cultivation, care

Description and botany

Solidago, also called solidage or Goldenrod, is a perennial herbaceous plant belonging to family Asteraceae, like daisies, asters and sunflowers. It is native to North America, particularly Canada, as well as the eastern and central United States where it grows in a wide range of habitats from mountainous areas and dry woods to cool meadows, sandy fields, fallow land and riverbanks.

The genus includes about 125 species, among them Solidago canadensis, or Canadian goldenrod, Solidago rugosa, Solidago gigantea or giant goldenrod. Many botanical species, now considered invasive, are increasingly being abandoned (and in some cases banned from sale) in favour of non-invasive hybrid varieties, such as Solidago ‘Goldenmosa’, ‘Crown of Rays’ (syn. ‘Strahlenkrone’) or species with a much less invasive character, such as Solidago Shortii or Solidago altissima, a tall goldenrod. Solidago virgaurea is in turn widely used for its medicinal properties.

From a more or less running rhizomatous crown, Goldenrod forms a dense, erect clump with a flexible, airy habit, sometimes slightly trailing (Solidago ‘Fireworks’) made up of many leafy stems ranging from 0.30 m for dwarf forms to 2 m in flower for the largest goldenrods such as Solidago altissima. Fast-growing, these stems can, depending on species, reach up to 1 m in a single season.

Once well established, this rhizomatous perennial grows quickly to form dense clumps that can become invasive in favourable conditions, but new varieties have a moderate habit that makes them suitable for all gardens. They will need about two years to thicken up and reach their full potential.

Solidago vigaurea – botanical illustration

On hairy, erect stems, sometimes arching and branched in their upper parts, a deciduous foliage unfolds. Leaves are lanceolate to linear with dentate margins, arranged alternately along the stems. Shiny bright green to chartreuse above, they are pubescent beneath and rough to the touch. Some species have stems of a reddish‑purple colour.

Sunny and spectacular, flowering takes place from July to October, depending on climate and variety, erupting from the fine foliage like a shower of gold. A myriad of small flowers gathered in light, arching panicles appears at the tips of the flexible stems. These highly branched spikes are compact or arranged in pyramids according to species. All bear tiny, fluffy heads 5 to 8 mm across, resembling miniature daisies or mimosa, made of five pedunculate lobes that bend together in the same direction. They burst into sprays, often gracefully drooping, in shades of pale yellow, bright lemon yellow to golden yellow, hence the vernacular name “Goldenrod”!

Although not fragrant, this generous flowering rich in pollen and nectar is particularly melliferous, attracting pollinating insects well into winter.

The radiant inflorescences of goldenrods will make airy, country-style summer and autumn bouquets. They can also be dried for use in dried bouquets.

Once pollinated, these flowers give way to tiny winged fruits containing very numerous fine seeds that are quickly dispersed by wind to self-sow wherever they land.

With its luminous plumes, Solidago brings colour and cheer from summer to autumn and fully deserves a place in all natural gardens. Large goldenrods such as Solidago altissima are planted at the back of a border, with other vigorous perennials or on the banks of a pond. Dwarf species like Solidago canadensis ‘Gold King’ are reserved for path or bed edging.

Solidago or Goldenrod has also been used for centuries in herbal medicine for its medicinal virtues, notably to treat colds, pulmonary and kidney ailments. Used externally, Goldenrod promotes wound healing, hence its Latin name meaning “to consolidate”.

Goldenrod is an edible plant; its flowers, stems and leaves, with a honey-like flavour, are consumed dried as infusions and herbal teas.

Main species and varieties

Most popular

Our favourites

Solidago Goldenmosa

Part of these new hybrid varieties, more compact, particularly bright and non-invasive. Adapts to all gardens.

• Flowering time August to October
• Height at maturity 75 cm

See the product sheet

Solidago Strahlenkrone

Striking hybrid variety with the advantage of being non-invasive. Also notable for earlier flowering. Indispensable in all gardens, even the smallest!

• Flowering time August to October
• Height at maturity 75 cm

See the product sheet

Solidago canadensis Gold King

Variety more compact than type species. Suitable for all gardens, in beds, borders or even in a pot on terrace.

• Flowering time August to October
• Height at maturity 75 cm

See the product sheet

Solidago rugosa Fireworks

This goldenrod stands out for a very pretty compact, trailing habit and for its non-invasive character. Perfect for structuring a large perennial bed or low bushes.

• Flowering time August to November
• Height at maturity 1 m

See the product sheet

Solidago rugosa

Botanical species distinct from horticultural varieties, with a more airy habit and flowering in large weeping sprays. Will find its place in all gardens.

• Flowering time September to November
• Height at maturity 90 cm

See the product sheet

Planting

Where to plant goldenrod?

Easy to grow and very hardy to at least -20 °C, Goldenrod can be cultivated throughout France. It prefers full sun for best flowering, although partial shade in southern regions is preferable. Reserve for taller varieties, which can reach nearly 2 m in height, a spot sheltered from strong winds that could make clumps flop over.

Undemanding, this vigorous perennial will do well in any good garden soil, even coping with poor, calcareous or occasionally dry soil. However, goldenrod will be more luxuriant in a cool, slightly acidic soil, even a bit heavy or very clayey but well drained. In dry ground, flowering may be less spectacular.

While recent varieties are noticeably less invasive than botanical species, give them enough space because goldenrod tends to overshadow neighbouring plants.

A well-exposed position will encourage tall goldenrods to show their full height.

The giant goldenrods are planted in groups in middle or back of naturalistic borders, where they bring a vapoury relief and striking verticality. They are incomparable for structuring a large border of perennial plants or low bushes. Very graphic, they are perfect for composing rural late-season scenes, full of vigour, lightness and cheer in every corner of a natural and naturalistic garden, in wildflower meadow and even by water or at a vegetable garden where they attract pollinating insects.

Dwarf or low goldenrods give breath to path edges, mixed borders and to a rockery that is not too dry.

When to plant?

Planting Goldenrod is done in spring, from February to April, after frosts, or in autumn, from September to November, after the high summer heat.

How to plant?

In ground

Although Solidago tolerates ordinary well-drained soil, it will flower more abundantly in cool soil. In poor soil it will cope but will probably be less floriferous: add well-rotted compost or potting compost at planting. Solidago can be planted singly, or in groups of three plants per m2 for a dense, striking effect: space plants 30 to 80 cm in all directions according to mature size. Staking may be necessary for large specimens.

Leave space for them because some goldenrod species can be quite invasive and may colonise ground to the point of preventing other plants placed too close from growing.

• Dig a hole 2 to 3 times the volume of the bucket
• Spread a bed of gravel at bottom of planting hole
• Add one or two handfuls of compost to garden soil
• Stake if necessary
• Water regularly after planting until established
• Mulch to keep soil cool during summer

If you prefer not to stake: plant goldenrod with other tall perennials and bushes that it can lean on to prevent flower stems collapsing at slightest gust of wind.

And follow our tips to succeed in planting your perennial plants!

In pots

• Plant Goldenrod in a large pot of at least 7.5 litres
• Layer a good depth of drainage (gravel or clay balls)
• Plant in a mix of garden soil and good potting compost
• Add a handful of compost
• Mulch and water very regularly: this guarantees a good flowering

Caring for Solidago

Once well rooted, Solidago requires little care, becoming more luxuriant year after year.

In warm regions, mulch the base during summer to keep soil sufficiently cool through the growing season. Water regularly, but without waterlogging soil. It will tolerate occasional drought, provided watering remains regular.

In a pot, water more frequently, never allowing substrate to dry out.

Taller clumps, very sensitive to wind, will need staking, especially in windy areas.

Withered inflorescence in autumn then frosted in winter

Rather fertile soil favours its development: fertilise each year at the start of spring, adding compost by superficially forking it in.

Remove faded flowers regularly to encourage flowering and to prevent excessive self-seeding.

If you wish to harvest them: pick the tops just before flowers open and hang these bunches upside down out of light to dry.

In autumn or late winter, clean away dead foliage and cut back dried clump to 50 cm above soil.

If you planted a vigorous species of goldenrod in spring or autumn, divide clumps to restore vigour and contain spread.

Diseases and potential pests

Easy to grow, le Solidago is disease-free, except perhaps powdery mildew which leaves a white coating on leaves during drought or at season’s end, when weather is warm and humid. Avoid excess water that favours development of the fungus, water at base of plant avoiding foliage and follow our advice to limit occurrence of powdery mildew.

Foliage of Solidago dies back in winter and reappears in spring, when young shoots then become target of slugs and snails. Discover our 7 effective, natural ways to control slugs and how to make a slug trap.

Propagation: Dividing clumps

If goldenrod has a natural tendency to self-seed or spread on its own, it can also be easily propagated by dividing the clump in spring, on mature stumps at least 3 or 4 years old.

• Using a digging fork, lift the clump gently
• Divide off a few offsets from around the edge of the clump
• Replant immediately into well-drained, enriched, fresh soil

Using Solidago in the garden

Reliable choice for naturalistic gardens, goldenrod is unmatched for lightening compositions and inspiring wild, abundant-looking scenes with elegant simplicity. Its sunny shades are welcome in late summer and early autumn.

While large goldenrods structure the back of naturalistic beds, their versatile nature also allows them to bring movement to borders, mixed-border or to punctuate with their tall habit the prairies fleuries.

Solidago is perfect to take over flowering between summer-flowering perennials and late-flowering perennials.

Planted in numbers rather than singly, giant goldenrod gives body to a bed with its intense yellow colour, which pairs easily with complementary blue or violet tones of Asters, Sages, hardy geraniums, Echinops, Perovskia or a Penstemon.

For a display of explosive tones, combine with Echinaceas, Oriental poppies, daisies, Agastaches, Helianthus.

A naturalistic combination idea: Aster novae-angliae ‘Purple Dome’ (or ‘Violetta’ taller up or a mix with ‘Little Carlow’), Solidago (altissima at back of bed or ‘Gold King’ or rugosa), Panicum virgatum ‘Shenandoah’, Helenium ‘Sahin’s Early Flowerer’ (and/or Helenium ‘Rubinzwerg’), Miscanthus sinensis ‘China’, and Monarda ‘Scorpion’… you can also add Kniphofias, cannas…

Its relaxed habit offers a contrast of form with plants equally rich in colour but with crisper outlines, such as dahlias, kniphofias, cannas, calmed by light grasses (Miscanthus).

In a bed dominated by yellow tones, goldenrod asserts itself alongside golden tansy, Heleniums, Rudbeckias and Achilleas, with grey or bluish foliage tempering the scene, such as Artemisia, Santolina, Stachys, Hostas, blue fescues.

At the edge of a bed, smaller goldenrods will work wonders alongside coreopsis, small daylilies and leucanthemums.

A living mulch of ground-cover perennials such as Heucheras, periwinkles or bugles or annual flowers like nasturtiums and marigolds will keep soil cool at its feet.

To accompany late-summer blaze through to early winter, the bright yellow of its spikes will resonate with perennials with flamboyant tones such as Helenium, perennial chrysanthemums or autumn daisies and with annuals such as Bidens, calendula or lantanas.

Goldenrods will set off all warm tones planted beneath bushes with colourful autumn foliage such as deciduous Euonymus, purple oak, Parrotia persica or Cotinus.