Riddell's goldenrod (Solidago riddellii)

Overview

Riddell’s goldenrod is a standout native perennial prized for its dense clusters of vibrant yellow flowers that arrive late in the season, extending garden color well into the autumn months. This species, Solidago riddellii, provides crucial late-season nectar sources for vital pollinators when many other plants have finished blooming. Its stiff stems and flat-topped flower arrangement give it a clean, architectural appearance, especially useful in naturalized settings.

This herbaceous perennial is relatively easy to cultivate, provided its essential water needs are met. Solidago riddellii naturally thrives in seasonally wet meadows, making it an excellent anchor plant for rain gardens where consistently moist or soggy soil prevails. It offers robust color and structure without demanding intensive care, fulfilling the needs of the busy ecological gardener.

Although often confused with nuisance species, this particular goldenrod is perfectly suited for wet, sunny areas. The reliable late-summer and fall display provided by Riddell’s goldenrod makes it indispensable for late-season interest, supporting local ecosystems while beautifying the landscape.

Fast Facts

• Plant Family: Asteraceae
• Plant Type: Herbaceous perennial
• Native Range: North-central North America
• Hardiness Zones: USDA Zones 3-7
• Size at Maturity:
  • Height: 2-3 ft
  • Spread: 1.5-2 ft
• Bloom Time: September to October
• Bloom Description: Yellow
• Sun Exposure: Full sun
• Water Needs: Wet
• Maintenance Level: Low

How to Grow

Plant Riddell’s goldenrod in springtime or fall, ensuring a location that receives full sun exposure throughout the day. This plant demands consistently wet soils; it performs best in conditions that mimic its native wet meadows or swales. While adaptable to clay soil, the most crucial factor is moisture retention; avoid dry, arid locations at all costs.

Maintenance for Solidago riddellii is minimal. It requires little to no supplemental fertilization when grown in appropriate native soil conditions. While generally hardy, ensure you remove spent flower clusters after blooming to encourage vigor and potentially a longer bloom period, although this isn’t strictly necessary for survival.

As a vigorous spreader, this goldenrod may need division every second or third year to maintain tidy clumps, especially in smaller garden spaces. No specialized winter preparation is generally required; allow the stiff stems to stand through winter for textural interest until you clear them away during early spring cleanup before new growth emerges.

Landscape Uses

The primary aesthetic role for Riddell’s goldenrod is providing reliable, structural color in wet areas. It excels in rain gardens, fulfilling its suggested use perfectly by absorbing excess water while contributing late-season blooms. Consider planting large drifts of this plant to create sweeping, naturalized areas within wet meadows or prairie restoration projects.

Due to its height (2-3 feet) and upright habit, Solidago riddellii works wonderfully toward the middle or back of a mixed border dedicated to native species. Pair it with other moisture-loving plants that bloom earlier in the season, such as Swamp Milkweed (Asclepias incarnata) or Cardinal Flower (Lobelia cardinalis), setting up a continuous flow of texture and color across the growing season.

Its presence in native plant gardens acts as a vital late-season food source for late-flying bees and butterflies. In naturalized settings, its strong vertical accent contrasts beautifully against coarser textures found in rushes or sedges that occupy similar wet habitats.

Standout Features

Flower Qualities

• Showy

Noteworthy Characteristics

Solidago riddellii is a somewhat rare Missouri native goldenrod which occurs only in wet meadows in the Ozark region of the State. Features tiny, bright yellow flowers borne in dense, erect, flat-topped, terminal, corombose inflorescences atop stiff, glabrous stems typically growing 3-4’ tall. Goldenrods have been wrongly accused of causing hay fever which is actually an allergic reaction to wind-borne pollen from other plants such as ragweed, ensuring that this beautiful native is safe for most allergy sufferers.

Tolerances

• Deer
• Clay Soil
• Wet Soil

Potential Problems

This plant boasts very low fuss requirements; the primary cultural threat is insufficient moisture, leading to stress, although leaf rust is an occasional cosmetic problem. Monitor for leaf rust, particularly in humid conditions, and address it by ensuring good air circulation if possible, or by removing heavily infected foliage. Over time, vigorous growth may necessitate division every 2 to 3 years to control clump size and prevent overcrowding, an easy task given its preferred wet growing conditions.

Frequently Asked Questions

What hardiness zones is Riddell’s goldenrod suitable for?

Riddell’s goldenrod is quite cold-hardy and is suitable for planting in USDA Zones 3 through 7.

How large does Solidago riddellii grow?

This species typically reaches a mature height between 2 and 3 feet tall, with a spread ranging from 1.5 to 2 feet wide.

What sun exposure does Solidago riddellii need?

For optimal flowering and robust health, Solidago riddellii requires consistent full sun exposure.

When does Solidago riddellii bloom?

Riddell’s goldenrod produces its attractive yellow flowers reliably from early September through October.

Conclusion

Solidago riddellii, or Riddell’s goldenrod, offers essential late-season vibrancy and superior ecological value, especially for gardeners managing damp environments. Its low maintenance and deer resistance make it a practical choice for naturalized areas and specialized rain gardens. Before planting, confirm that you can provide the required full sun and consistently wet soil conditions for this exceptional native perennial.

Companion Planting

When designing a landscape for Solidago riddellii, focus on partners that share its love for wet feet and full light. Wetland-loving irises (like Iris versicolor) provide earlier spring and early summer interest before the goldenrod takes center stage. Consider pairing it with Blue Flag Iris or native sedges which help stabilize the soil while meeting similar hydrological requirements.

For texture contrast, native grasses that tolerate moisture, such as Blue Joint Grass (Calamagrostis canadensis), work beautifully alongside the stiff, upright stems of Riddell’s goldenrod. These grasses mimic the prairie environment familiar to Solidago riddellii, ensuring a cohesive, naturally thriving habitat feature that maximizes biodiversity.

Wildlife Benefits

As an Asteraceae family member, this plant is a powerhouse for late-season pollinators. The dense terminal flower heads of Riddell’s goldenrod offer abundant pollen and nectar precisely when many other garden staples have faded, making it critical for migratory butterflies and bees preparing for winter.

The flowers attract a wide variety of beneficial insects, enhancing the ecological function of your rain garden or meadow. While deer typically avoid this genus, the plant’s presence contributes significantly to local food webs, supporting the insect populations that sustain local birdlife through late autumn.