Mountain fleece (Persicaria amplexicaulis 'Firetail')
Persicaria amplexicaulis 'Firetail' (Mountain fleece) offers continuous crimson blooms from June to October. A low-maintenance perennial for wet to average soils.
Complete Plant Information
Overview
Persicaria amplexicaulis ‘Firetail’, commonly known as Mountain fleece, is a highly valued herbaceous perennial cherished for its long season of vibrant color. This plant establishes a dense, leafy mound that provides excellent texture throughout the growing season, dramatically peaked by its striking flower display. Gardeners rely on this species for reliable performance in areas that stay moderately moist, offering a substantial vertical element without demanding high upkeep.
The distinctive feature of Persicaria amplexicaulis ‘Firetail’ is its terminal spikes of crimson red flowers that continuously emerge from early summer until the first frost. Native to the Himalayas, this species brings structural interest and bold color to borders and woodland settings. Although it spreads slowly when conditions are optimal, it is not considered invasive, allowing it to naturalize gracefully where given sufficient space.
The appeal of Mountain fleece lies in its versatility and ease of culture, thriving in diverse light conditions ranging from full sun to partial shade. Its tolerance for wet soil makes it an excellent choice for pond margins or rain gardens where many other perennials might struggle. For a robust, long-blooming specimen, planting Persicaria amplexicaulis ‘Firetail’ ensures months of rich, textural color.
Fast Facts
- Plant Family: Polygonaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 4-7
- Size at Maturity:
- Height: 3-4 ft
- Spread: 3-4 ft
- Bloom Time: June to October
- Bloom Description: Crimson red
- Sun Exposure: Full sun to part shade
- Water Needs: Medium to wet
- Maintenance Level: Low
How to Grow
Plant Mountain fleece in the spring or fall once the threat of hard frost has passed, ensuring it is placed in well-drained soil that supports its tendency toward medium to wet requirements. While it adapts to average soils, consistent moisture is crucial, especially if sited in a sunnier spot to encourage profuse flowering and prevent heat stress. If growing in sunny locations, be diligent about watering, particularly during dry spells.
This perennial requires low maintenance once established. Generally, supplemental fertilizing is unnecessary unless the soil is extremely poor. Due to its stature, staking may be required if a location unprotected from strong winds is chosen, as the tall spikes can become top-heavy. Deadheading spent flower spikes is typically not required, as the plant maintains its appearance well into the late season.
Over time, Persicaria amplexicaulis ‘Firetail’ will slowly spread to form substantial clumps. Gardeners should allow it ample room, as crowding can reduce air circulation and vigor. If necessary, division can be performed in early spring, although this plant is often best appreciated when allowed to mature into a large, established presence. Appreciating the subtle architectural element of its stem nodes, which appear jointed due to the stem-clasping leaf stipules, is part of enjoying this species.
Landscape Uses
Mountain fleece excels in settings requiring perennial height and moisture tolerance. Grouping or massing Persicaria amplexicaulis ‘Firetail’ creates dramatic sweeps of deep red color, especially effective in woodland garden contexts or along naturalized borders where reflected light enhances the crimson blooms. It performs admirably near pond margins or in specialized bog gardens, fulfilling its need for consistent moisture.
Consider pairing this robust perennial with plants that offer contrasting foliage textures or colors when the Mountain fleece is not blooming, such as silvery foliage or finer-textured grasses. It works perfectly in cottage garden designs where informal masses of color are desired, or as a sturdy upright element within a mixed border against shorter, sun-loving companions.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Persicaria amplexicaulis, commonly known as mountain fleece or red bistort, is an herbaceous perennial that typically grows in a dense leafy mound to 3-4’ (infrequently to 6’) tall and as wide. It is native to the Himalayas. Tiny, rose-red to white flowers bloom June to September (occasionally to first frost) on narrow, pencil-thin, long-stalked spikes (to 4” long). Opposite, ovate to lanceolate green leaves (to 6” long) are slightly puckered, acuminate (tapered to a sharp tip) and cordate-based with downy undersides. Leaves are distinctively stem-clasping (amplexicaul), with leaf stipules sheathing the stem, giving the stem a jointed appearance at each leaf node. Plants often form large clumps over time. Formerly known by the synonymous name of Polygonum amplexicaule.Genus name comes from the Latin persica meaning peach-like and sagittata meaning barbed or arrow-shaped in reference to the shape of the leaves.Specific epithet means stem-clasping in reference to leaf attachment.‘Firetail’ typically grows to 3-4’ tall. Red flower spikes grow to 6” long. Flowers appear throughout summer to first frost. Ovate leaves are prominently veined. Plants are not invasive, but need lots of space
Tolerances
- Deer
Potential Problems
Persicaria amplexicaulis ‘Firetail’ generally exhibits excellent resistance to most common garden pests and diseases. Serious insect infestations or fungal issues are rarely reported for this reliable Perennial. Proactive management focuses on providing the correct environment, specifically ensuring adequate air circulation and consistent, but not stagnant, moisture levels.
If the plant is excessively crowded in hot, dry conditions, minor mildew issues might occasionally arise, but this is uncommon. If growth appears stunted or flowering is sparse, reassess the site’s moisture and sun exposure, as these are the key drivers for Mountain fleece vigor.
Frequently Asked Questions
What hardiness zones is Mountain fleece suitable for?
Persicaria amplexicaulis ‘Firetail’ thrives in USDA Hardiness Zones 4 through 7, offering reliable perennial performance across a wide range of temperate climates.
How large does Mountain fleece grow?
This cultivar typically matures to a height between 3 and 4 feet tall, with a similar spread of 3 to 4 feet, forming a dense, substantial clump.
When does Mountain fleece bloom?
Mountain fleece provides exceptional value by blooming consistently from June all the way through to October, displaying vibrant crimson red flower spikes.
What sun exposure does Persicaria amplexicaulis ‘Firetail’ need?
For the best flowering performance, aim to plant Persicaria amplexicaulis ‘Firetail’ in locations receiving full sun to partial shade, adjusting water if placed in hotter, brighter conditions.
Conclusion
The longevity of bloom—stretching from June through October—makes Persicaria amplexicaulis ‘Firetail’ an indispensable component for late-season interest in any garden design. Its striking crimson flowers and robust, low-maintenance nature solidify its status as a gardener favorite. Before planting, confirm that your site aligns with the USDA Zones 4-7 range and that you can meet its preference for medium to wet soil conditions.
Companion Planting
When selecting partners for Mountain fleece, emphasize plants that appreciate or tolerate moist soils, complementing its mid-to-late season bloom period. Consider pairing with Japanese Forest Grass (Hakonechloa macra) for weeping, fine texture contrast against the broad leaves of Persicaria amplexicaulis ‘Firetail’. For late-season structure, Astilbes that bloom earlier, or various ornamental sedges and ferns (which appreciate the part-shade tolerance of Mountain fleece), make excellent companions.
In brighter, wetter conditions, robust perennials like Candelabra Primula (Primula japonica) or Iris sibirica offer elegant height and color that harmonize well with the habit of the Mountain fleece. These pairings help create lush, layered planting schemes ideal for woodland edges or stream banks where consistent moisture is naturally available.
Propagation Tips
The primary and easiest method for increasing your stock of Persicaria amplexicaulis ‘Firetail’ is through division. Since plants slowly form large clumps over time, dividing them is essential maintenance that also yields new specimens. Perform this division in the early spring just as new growth is initiating, ensuring each resulting division has a healthy amount of roots and emerging shoots.
While the plant can self-seed, relying on division provides quicker, more reliable results true to the ‘Firetail’ cultivar characteristics. Ensure that divisions are replanted quickly into prepared, moist soil to minimize transplant shock. This toughness in division makes the perennial easy to propagate year after year.
