Pickerelweed (Pickerel Rush) Facts, Care, Benefits, & Hardiness (Pontederia cordata)
Pickerelweed, also called a pickerel rush, is a standout member of the water hyacinth family native to a large swathe of North America from the Northeastern Canada down to the Caribbean, and from the East Coast inland to the Great Plains. Pickerelweed is a sizeable plant, with lance-shaped leaves averaging 13cm in width and 26cm in length (5in x 10in). It is best identified by a spike of blue-purple flowers that erupt from a single stem beneath the water.
These plants regularly reach heights of 1m (3ft). The pickerel fish, commonly known as the northern pike, has a strong preference for living amongst the shady leaves of this plant, giving it its nickname. Its scientific name, however, pays homage to an Italian botanist, Giulio Pontedera (1688-1757), who studied flowering plants as a professor at the University of Padua.
Indigenous peoples from across much of eastern North America have written about pickerelweed over the centuries. The Anishinaabe people of Ontario, Manitoba, Minnesota, and North Dakota, referred to pickerelweed as “kinozhaeguhnsh,” which translated to “pike’s plant.” Again, this appears to be a reference to its ability to somehow attract these fish—although no specific breeding or feeding interaction between these two organisms has yet been uncovered. Several Native American tribes, including the Montagnais (Quebec and Labrador), the Micmac (Nova Scotia, P.E.I., Newfoundland), and the Malecite (New Brunswick and Maine), have reportedly used pickerelweed in medicine and steeped in tea as a general cure-all.
Does Pickerel Weed Have Any Benefits?
Many insects enjoy feeding on or seeking shelter in pickerelweeds. Damselflies and dragonflies are known to lay eggs at the plant’s base. For this reason, gardeners who want to attract dragonflies report having great success when planting pickerelweed. Pickerelweed is also a favorite of bumblebees (Bombus spp.) and other bee species, Melissodes apicatus and Dufourea novaeangliae, which preferentially scavenge pollen from pickerelweed. Sulfur butterflies may forage the plant’s nectar, and certain Borer moth larvae including that of the Pickerelweed, White-Tailed Diver, and Cattail moths (Bellura densa, Bellura gortynoides, and Bellura oblique, respectively) feed on its stalks, leaves, and petioles.
Pickerelweed Growth, Hardiness & Wintering
Pickerelweed is a hearty grower and can reach a height of 1.2m (4ft) and spread of 0.6m (2ft) in diameter. These plants prefer to grow in full sunlight, and will show their environmental satisfaction by sprouting its eye-catching flowers. Flowers bloom continuously beginning in early summer and continue to do so, albeit less robustly, during the fall. Its natural habitat reaches up into Nova Scotia, indicating that Pickerelweed is capable of surviving harsher climates. It grows in USDA hardiness zones 3 to 10, meaning that it can withstand minimal winter temperatures of -40 to -37°C (-40 to -35°F).
How to Plant Pickerelweed (Pickerel Rush)
Pickerelweed can either be planted your pond margins at the start of spring, or in a pot of sandy or clay loam. These plants should be submerged in a maximum of 13cm (5in) of water. It is important to note that the fibrous root systems of pickerelweed can expand and infiltrate other areas of your pond. To prevent this, simply plant in a container. Pickerelweed can also be planted from seeds by spreading 20 to 30 live seeds per square foot or 1/3 square meter. These seeds germinate in cool, moist, loose soil so planting just beyond the pond margin or in a regularly watered pot is recommended.
How to Care for Pickerelweed (Pickerel Rush)
The most important care instructions for pickerelweed is that it must be kept wet and in direct sunlight. All other considerations such as fertilizer and temperature are secondary. Since pickerelweed is such a great grower, it is recommended that you divide the plant every few growing seasons so it does not get too large. To do so, dig up the plant and cut through the thick mat of roots, called rhizomes, to separate out a section of healthy leaves and roots. Replant one of the sections and use the other to start a new plant.
If left unattended, pickerelweed will grow into thick colonies like they do in the wild. It is also important to keep your water levels between the base of the stem and the bottom of the leaves; water levels should exceed the height of the lowest-growing leaves.
How to Winter Pickerelweed:
To overwinter, cut back the pickerelweed and ensure the crown of the plant (the area where the stem joins the roots) is submerged in at least 10cm (4 in) of water. Pickerelweed can survive winter as long as the crown does not freeze.
Is Pickerelweed Toxic, Poisonous or Invasive?
The classification of pickerelweed as a “weed” can be considered a misnomer. Unlike other weeds that are undesirable and provide little in terms of appearance, pollinator attraction, or utility, pickerelweed is a favorite plant of gardeners and ecologists. Although they grow rapidly and across a wide range, pickerelweed has not become an invasive or noxious weed. In fact, it is considered threatened in the U.S. state of Kentucky.
Will Koi, Goldfish, & Animals Eat Pickerelweed?
Pickerelweed is edible to both animals and humans, alike. Many individuals like to harvest the spikey seeds from pickerelweed flowers collected in the fall at the end of its season. These seeds can be roasted, eaten raw, or ground into flour, and make a delicious addition to homemade granola. Horticulturists are not the only garden dwellers that have found their pickerelweed to provide a tasty snack. Deer will voraciously feed on the leaves of this aquatic plant while ducks and muskrats prefer its seeds.
In terms of koi and goldfish, although they’re unlikely to eat the rhizomes, stem or leaves of the plant, they still may consume the seeds that happen to drop into the pond water.