Many Persicaria share 2 similar features: showy leaves and an aggressive nature. Persicaria polymorpha
, or Giant Fleece Flower, doesn’t have showy leaves, but you’ll never miss them. And it tends to be quite well behaved in the garden. Giant Fleece Flower blooms in early summer and goes on until fall, getting taller and taller along the way.
Persicaria polymorpha is sometimes confused with Polygonum cuspidatum or Japanese Knotweed, which is considered an invasive. I haven’t seen anything to suggest that Persicaria polymorpha should be grown with caution, but please let me know if you do.
Persicaria polymorpha, Syns: Bistorta polymorpha, Polygonum polymorpha
Common Name: Giant Fleeceflower, White Fleece Flower, White Dragon
4 - 6' (h) x 4 - 8' (w).
Early summer through Fall. Flowers produce attractive seedheads in fall.
Giant Fleece Flower looks like a shrub but grows like a herbaceous perennial, dying back in the winter. It makes up for it by quickly growing upwards of 6' the following season. Giant Fleece Flower stays in a well behaved clump and rarely seeds or spreads by rhizomes. It is widely adaptable and requires little maintenance.
Leaves: Dark green, alternate pointed leaves have slightly serrated edges. The stems are sturdy, but may need some support by the end of summer.
Flowers: Astilbe-like white plumes are popular with butterflies. The late season seed heads are also attractive.
I don’t know of any cultivated varieties of Persicaria polymorpha.
Because of its size, Giant Fleece Flower will make a statement anywhere in the garden, but it’s white plumes make it especially useful for a partial shade garden. It’s great for any border than needs a vertical accent and also works well as a screen or to block something like an air conditioning unit. Just be sure to give your plant plenty of room. It will fill out quickly.