Rusty foxglove (Digitalis ferruginea 'Gelber Herold')
Discover Digitalis ferruginea 'Gelber Herold', the Rusty foxglove, valued for its striking yellow spires and low maintenance in part shade conditions.
Complete Plant Information
Overview
Digitalis ferruginea ‘Gelber Herold’, commonly known as Rusty foxglove, offers dramatic architectural height to the garden, rising on slender spires that bloom in early summer. This cultivar stands out due to its unique creamy yellow to pale golden brown flowers, which feature distinctive rusty veining inside the narrow tubes. Gardeners value the Rusty foxglove for its striking vertical accent, making it an excellent choice for the middle or back of perennial borders.
While often categorized as a perennial, Digitalis ferruginea ‘Gelber Herold’ typically behaves as a biennial or a short-lived perennial, producing a basal rosette of leaves in its first year before flowering spectacularly in its second. Once established, it readily self-seeds, often ensuring a continuing display year after year if spent spikes are selectively left in place. This reliable performance, combined with its low maintenance needs, makes the German-derived ‘Gelber Herold’ a superior choice for adding structure to partially shaded garden spaces.
Fast Facts
- Plant Family: Plantaginaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 4-8
- Size at Maturity:
- Height: 3-5 ft
- Spread: 1-1.5 ft
- Bloom Time: June to July
- Bloom Description: Yellow with interior rusty veining
- Sun Exposure: Part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
Planting Digitalis ferruginea ‘Gelber Herold’ is best done in spring after the threat of frost has passed, either by sowing seeds directly or transplanting established starts. This plant thrives in average, medium, well-drained soil, but it shows a preference for soil that is organically rich and slightly acidic. Ensure the location receives part shade, as too much intense afternoon sun can scorch the foliage, especially when combined with dry conditions.
Watering requirements are medium; the soil should never be allowed to dry out completely, especially during its first year of establishing the basal rosette. Fertilization is rarely necessary if the soil is rich. The primary cultural consideration involves managing its life cycle: allow the basal rosette to overwinter as evergreen foliage before the flower spikes emerge in late spring or early summer.
Managing spent flower stalks is crucial for long-term presence. If you cut spikes back to the basal foliage immediately after the initial bloom fades, you encourage a secondary bloom, and prompt the plant to behave more like a true perennial. If you allow the spikes to go to seed, the plant functions more as a biennial, self-seeding freely to ensure subsequent generations, although the mature seed heads can look untidy.
Landscape Uses
The tall spires of Rusty foxglove provide crucial vertical elements, acting as beautiful architectural punctuation marks within the garden. They achieve their best effect when planted in front of darker backgrounds, such as dark green hedges or stone walls, which allow the pale yellow flowers of Digitalis ferruginea ‘Gelber Herold’ to truly pop visually. Consider grouping them in drifts rather than isolated individuals to maximize the impact of their height.
These foxgloves integrate well into woodland gardens where dappled light mimics their preferred part shade conditions. They also work effectively in naturalized settings where they can fulfill their tendency to self-seed, creating informal colonies over time. Companion planting ideas should focus on lower-growing, shade-tolerant perennials that can complement the vertical form, such as Hostas, Ferns, or Astilbes, ensuring the base of the foxglove remains attractive after flowering.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Digitalis ferruginea, commonly called rusty foxglove, produces a basal rosette the first year, with flowering occurring the second year on leafy spires reaching 3-5 feet tall. The flowers are pendulous, tubular, and creamy yellow with heavy rusty interior veining, a feature that distinguishes ‘Gelber Herold’. The genus name relates to the Latin word for finger due to the flower shape, while the specific epithet refers to its rusty coloration.
Tolerances
- Deer
Potential Problems
Digitalis ferruginea ‘Gelber Herold’ generally experiences few serious pest or disease issues, contributing to its low maintenance rating. However, fungal issues like powdery mildew and leaf spot can appear, especially in high humidity, leading to significantly depreciated summer foliage if left unchecked. Proper spacing and avoiding overhead watering can mitigate these fungal risks.
Crown rot is a notable concern if winter soils become soggy and poorly drained, emphasizing the critical need for well-drained conditions year-round. Potential pests include common garden nuisances such as aphids, mealybugs, slugs, and the occasional Japanese beetle, which can usually be managed through routine scouting or simple hand removal.
Frequently Asked Questions
What hardiness zones is Rusty foxglove suitable for?
Digitalis ferruginea ‘Gelber Herold’ is reliably hardy in USDA Zones 4 through 8.
How large does Digitalis ferruginea ‘Gelber Herold’ grow?
This variety typically reaches a height of 3 to 5 feet tall with a relatively narrow spread of 1 to 1.5 feet.
When does Rusty foxglove bloom?
The bloom time for this plant is generally from June into July, featuring tall spires of yellow flowers with interior rusty veining.
What sun exposure does Digitalis ferruginea ‘Gelber Herold’ need?
This plant performs best when sited where it receives part shade throughout the day.
Conclusion
The striking architecture and unique yellow-and-rust coloration establish Digitalis ferruginea ‘Gelber Herold’ as a standout accent plant for shaded borders. Its low maintenance profile, coupled with its strong vertical presence as the Rusty foxglove, makes it an easy long-term addition to the garden, provided you appreciate its biennial tendencies. Plan your planting now, ensuring excellent drainage, to enjoy its summer performance.
Companion Planting
When selecting companions for Digitalis ferruginea ‘Gelber Herold’, prioritize other semi-shade lovers that offer contrasting textures or bloom times. Hostas provide lush, broad foliage to contrast with the foxglove’s slender spires, absorbing light close to the ground. Consider shade-tolerant bulbs like Lily of the Valley (Convallaria majalis) for early spring interest before the foxglove emerges from its overwintering rosette.
For mid-summer color that complements the yellow tones, look towards Hellebores or Heuchera, particularly those varieties with dark purple or bronze foliage. These companions share the preference for moist, organically rich soil, simplifying the overall care routine for this section of the garden border.
Seasonal Care Calendar
Spring: Once new growth emerges, ensure consistent moisture while the flower spikes are developing. Apply a light layer of compost around the base of the plant if soil improvement is desired, but avoid burying the basal crown. This is the ideal time to decide whether to remove all spent flower stalks (for rebloom) or leave a few for self-seeding.
Summer (Post Bloom): Promptly cut back spent flowering stalks. If you cut them back to the basal foliage before seeds fully set, you greatly increase the chance of a secondary summer bloom. Monitor soil moisture carefully during dry spells, as the foliage can quickly wilt if the medium dries out.
Autumn/Winter: The basal rosette of leaves for Digitalis ferruginea ‘Gelber Herold’ remains evergreen, offering winter structure. Apply a light mulch if winter drainage is questionable in your specific microclimate to help moderate soil temperatures and prevent crown rot in excessively wet conditions.
