Two summers ago, I planted Persicaria Firetail with some trepidation; I wasn’t convinced that it would grow in my area. Some sellers promised that it is winter hardy to USDA Zone 4 while others suggested Zone 5. Lucky for me, it survived its first winter in Zone 4, and by the end of the second season, it had grown sufficiently to be propagated.
I was attracted to this plant because of its casualness and its long bloom period. It appears to be the sort of perennial best suited to a cottage garden. It is also ideal for a flowerbed with a meadow theme, as it looks stunning when combined with ornamental grasses.
The most impressive characteristic of this plant is that by insinuating itself among other perennials – it must be seen to be believed - it weaves a theme of crimson through my garden to anchor all of the other hot colored flowers that bloom there.
Firetail will spread to 4 feet in diameter. By its second year, most of that spread appears to have taken place above ground. I cannot report with any accuracy if its root base, growing exponentially from its center, will also spread that wide underground. Nor am I able to predict if it will, or will not, choke out neighboring plants. More growing time is required to accumulate that information.
Crimson is not a color I would embrace in my English style pastel gardens, however, the brown fence that separates me from my neighbor calls for yellows, corals, and red flowers. Consequently, the flowerbed located in front of the fence has become home to yellow helianthus, heliposis, vivid achillea, and a variety of coral, tangerine, and scarlet-colored hemerocallis. A crimson plant, like Firetail, that can hold its own in this tropically colored setting, is a welcome addition.
The second most impressive characteristic about this plant is the longevity of its flowers; it blooms June to October and sometimes to the first frost. In the future, I will have to decide if its extended bloom period warrants growing such a spreading plant in an urban flowerbed.
The third most impressive characteristic about this sprawling plant is the root ball. While fleshy and dense, it is easily divisible from its extremities.
Persicaria amplexicaulis Firetail, also known as Polygonum amplexicaule Firetail, is a tall, upright, spreading perennial, which forms large, dense, bushy clumps of leathery dark green leaves, typically 3 to 4 feet tall. This tall foliage supports bottle brush-shaped crimson flowering spikes, up to 6 inches long, which bloom all summer.
This plant needs elbow room to achieve its potential. Without ample space, it will weave itself among other perennials, which, frankly, is a rather artistic way to grow this plant.
As it crochets its way throughout my flowerbed, it is about to enter year three of its growth. Therefore, I am unable to report on its long-term development. One of the problems with recently introduced varieties is that there is no established garden lore to guide us. Who can predict how it will behave when it matures?
Sellers recommend this plant for massing in moist areas, but I have grown it in a rather dry location. Perhaps that is why it took two years to make its presence felt.
Unlike its white, spectacular cousin, the strongly territorial Persicaria polymorpha, this cultivar is not too aggressive. However, like its cousin, it needs lots of space to grow. While this plant is a steady spreader, it is not considered to be invasive. Only time can judge that characteristic, because one gardener’s spread might be considered another gardener’s invasion.
Firetail grows in sun and part shade, in normal, sandy, or clay soil providing the earth is moist. It attracts butterflies, and is deer and rabbit resistant. Due to its spreading habit, some might consider experimenting with it as ground cover.