Giant hyssop (Agastache 'Bolero')
Agastache 'Bolero' is a compact Giant hyssop, offering pink-purple spikes, fragrant foliage, and excellent pollinator appeal.
Complete Plant Information
Overview
Agastache ‘Bolero’, commonly known as Giant hyssop, is a highly sought-after hybrid valued for its vigorous growth and attractive presentation throughout the summer months. This compact cultivar forms dense clumps topped with lovely spikes of pink-purple, tubular blooms that reliably draw in hummingbirds and butterflies. The dark bronze-green foliage of Agastache ‘Bolero’ is wonderfully fragrant, releasing distinct anise or licorice notes when brushed against.
As a hybrid selection, Agastache ‘Bolero’ offers gardeners the benefit of showier flowers and robust performance compared to some native species. It succeeds best in full sun where it can fully develop its color display, though it tolerates slight amounts of afternoon shade. Its low maintenance profile and tolerance for heat and dry soil make it an excellent choice for contemporary, water-wise garden designs.
This Giant hyssop variety is particularly useful for adding vertical accents without excessive height, maturing around 16 inches tall. Its reliable blooming from mid-summer into early fall ensures continuous color interest after many early bloomers have faded, solidifying its reputation as a garden workhorse.
Fast Facts
- Plant Family: Lamiaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 5-9
- Size at Maturity:
- Height: 1-1.25 ft
- Spread: 1-1.25 ft
- Bloom Time: July to September
- Bloom Description: Pink-purple
- Sun Exposure: Full sun
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
For the best establishment, plant Agastache ‘Bolero’ in the spring after the danger of hard frost has passed. The single most critical requirement for success with this Giant hyssop is excellent soil drainage; it thrives in average, well-drained soil incorporating some grit or sand is ideal. Avoid heavy clay soils that stay saturated, as these conditions frequently lead to crown or root rot, especially over winter.
Once established, watering needs are medium; water deeply when the top inch or two of soil feels dry. While it handles some dry spells once rooted, consistent moisture during the peak heat of summer helps maintain strong flowering. Fertilizing is rarely necessary; rich soil can encourage flopping. This is a low-maintenance plant requiring minimal intervention.
Deadheading the spent pink-purple flower spikes encourages the plant to produce more blooms throughout late summer and early fall. In colder zones (Zone 5), leave the stems and leaves standing over winter; this provides insulation and protection for the crown, which is particularly helpful where winter survival might be questionable despite being rated hardy down to Zone 6 for many hybrids.
Landscape Uses
Agastache ‘Bolero’ is remarkably versatile, providing vertical interest and fragrant texture across numerous garden settings. Its compact stature makes it perfect for placing near the front or middle of perennial borders where its vibrant blooms can be easily appreciated. It integrates beautifully into cottage gardens, creating an airy, informal feel alongside coneflowers or lavender.
For sustainable landscaping, this drought-tolerant Giant hyssop is suitable for xeriscaping once established, requiring minimal supplemental irrigation. Furthermore, its robust stems and attractive flowers make Agastache ‘Bolero’ a valuable addition to cutting gardens; the fragrant foliage is as appealing in arrangements as the blooms are to pollinators.
Consider grouping several plants together in mass plantings or utilizing them in large containers. When planting near sunny borders, pair it with plants that appreciate similar soil conditions, such as sedums or coreopsis, ensuring the entire arrangement enjoys full sun exposure.
Standout Features
Flower Qualities
- Showy
- Good Cut
Noteworthy Characteristics
Agastache, commonly called giant hyssop, is a genus containing about 30 species of upright herbaceous perennials, most of which are native to North America. Agastache hybrids often have showier flowers and better winter hardiness than species plants. Hybrid flowers come in a variety of different flower colors including shades of red, orange, pink, yellow and white. Hybrids typically feature dense terminal spikes of tiny 2-lipped tubular flowers which bloom mid-summer to fall in many-flowered verticillasters (false whorls) atop 2-4’ tall stiff square stems clad with opposite pairs of serrate, fragrant (anise/licorice scented) gray-green to medium green leaves. Flowers are attractive to bees, hummingbirds and butterflies.Genus name comes from the Greek words agan meaning “very much” and stachys meaning “ear of wheat” in reference to the appearance of the flower spikes. ‘Bolero’ is a compact, vigorous, hybrid selection of giant hyssop that features loose spikes of pink-purple, tubular blooms atop a low clump of fragrant, dark bronze-green colored foliage. The flowers bloom from mid-summer to early fall and are highly attractive to hummingbirds, butterflies, and other insect pollinators. Mature clumps will reach up to 16” tall with a similar spread.
Tolerances
- Deer
- Dry Soil
Potential Problems
The primary threat to Agastache ‘Bolero’ involves soil moisture management. Crown rot and root rot are significant risks if the soil drains poorly, particularly clay soils that retain water during the dormant season. Always ensure planting sites allow water to move away freely.
While generally resistant to serious insect issues, gardeners should monitor for common fungal issues like rust, powdery mildew, and leaf spots, especially if air circulation is poor. Maintaining adequate space between plants when planting helps mitigate these humidity-related diseases. Deer typically find the fragrant foliage unappealing and tend to avoid grazing on this Giant hyssop.
Frequently Asked Questions
What hardiness zones is Giant hyssop suitable for?
Agastache ‘Bolero’ performs best in USDA Zones 5 through 9. Gardeners in Zone 5 should ensure it has a protected, well-drained site over winter.
How large does Giant hyssop grow?
This cultivar is compact, typically reaching between 1 and 1.25 feet in height with a spread of about 1 to 1.25 feet at maturity.
When does Agastache ‘Bolero’ bloom?
You can expect the showy, pink-purple blooms of Agastache ‘Bolero’ to appear consistently from July through September.
What sun exposure does Agastache ‘Bolero’ need?
This plant requires full sun exposure to produce the best bloom quality and maintain compact growth habits.
Conclusion
Agastache ‘Bolero’ offers an excellent combination of fragrant foliage, season-long color, and strong pollinator support with very low demands on the gardener. This vibrant Giant hyssop variety is an invaluable component for sunny borders and drought-tolerant designs. Before planting, confirm your garden meets the essential requirement of full sun and excellent soil drainage to ensure this spectacular hybrid thrives for years to come.
Wildlife Benefits
The tubular, pink-purple flowers of Agastache ‘Bolero’ are architecturally perfect for attracting long-tongued pollinators. Hummingbirds are strongly drawn to the nectar-rich spikes, making this an essential component of any wildlife garden dedicated to attracting avian visitors.
Beyond hummingbirds, the dense inflorescences serve as excellent landing platforms for butterflies seeking sustenance between July and September. Planting this Giant hyssop near outdoor seating areas maximizes your enjoyment of the constant insect activity it generates.
Propagation Tips
While Agastache hybrids like ‘Bolero’ often do not come true when grown from seed—meaning the resulting plants may vary significantly from the parent—vegetative propagation is highly recommended. Taking stem cuttings in the early summer is the most reliable way to preserve the exact characteristics of this specific cultivar.
Cuttings should be taken from non-flowering, semi-hardwood stems, usually between 3 to 4 inches long. Dip the base of the cutting in rooting hormone and place it in a sterile, moist medium, preferably kept warm and slightly humid until roots develop.
Dividing established clumps of Agastache ‘Bolero’ is also an effective propagation method, best performed in early spring just as new growth begins to emerge. Ensure each division has a healthy portion of roots attached before replanting immediately into well-drained soil.
