Ornamental · Pontederiaceae
Pickerelweed
Pontederia cordata
A poised native pond marginal that lifts blue flower spikes all summer, asking only for full sun and wet feet.
Full sun
USDA 3–10
2–4 ft · 0.6–1.2 m
Overview
Pickerelweed brings a quiet architecture to the water's edge, a native aquatic at home along ponds, ditches, and slow streams across much of North America. It roots in the mud at the shoreline and carries its leaves and flower spikes above the surface, the upright poise gardeners call an emergent marginal. Glossy, heart-shaped leaves anchor the clump, and from early summer into fall it raises soft spikes of violet-blue flowers that give the margin its rhythm.
There is a generosity to how it sits in a garden. Its flowers draw bees and other pollinators to the waterside, while ducks and waterfowl come for the seeds and foliage, so the pond feels alive with visitors. A hardy perennial, it reads through winters from zone 3 to zone 10, receding in fall and rising again from the rhizome each spring to renew the scene.
Two considerations shape how it fits a space. The roots must stay constantly wet to shallowly submerged, since this wetland plant asks for a permanent seat at the water, and the vigor that lends a shoreline its fullness will drift if left to its own devices. Set into a basket where the pond is small, it holds as a generous, well-mannered clump that keeps the whole picture in balance.
Care
The short version: give it full sun and keep its feet wet, rooted in rich mud or loam with the crown under just a few inches of water, and set the rhizomes in a basket so the planting stays composed.
Light
Pickerelweed shows its best in full sun, where the spikes come thickest and the whole clump reads strongest. It accepts partial shade, though a shadier seat means fewer flowers and a looser, leggier shape at the margin.
Water
This is a true wetland plant, so its roots want to stay constantly wet to shallowly submerged and never dry out. Set it in mud or rich loam with about 2 to 12 inches (5 to 30 cm) of water over the crown, or in boggy soil right at the shoreline. Take care not to place it deeper than roughly 12 inches (30 cm), since too much water over the crown can undo it.
Soil
Root it in rich organic loam or mud kept constantly wet to submerged. It is unfussy about pH, at ease anywhere from 6.0 to 8.0, so most pond mud gives it the footing it wants.
Temperature
Pickerelweed is remarkably hardy, holding from -40°F (-40°C) in winter dormancy up to around 100°F (38°C) in summer. That reach covers zones 3 through 10, so it keeps its place at the water across most of the country.
Humidity
Living at the water, it never wants for moisture in the air, so humidity is one less thing to consider. The high humidity of a pond edge is exactly the setting it favors.
Feeding
It asks little at the table and largely fends for itself. To encourage a fuller show, work an aquatic plant tablet into the soil through the spring-through-summer season, but keep it light, since the plant carries the scene on its own.
Pruning
Upkeep stays light and unobtrusive. Remove the spent flower spikes as they pass through the season, then cut back and clear the old, dead foliage in late fall or early spring before fresh growth appears.
Repotting
Every 2 to 3 years, lift the plant to divide and refresh a crowded clump. The cues are rhizomes bulging the basket, smaller leaves with fewer flowers, and the plant heaving up out of its pot.
Size & spacing
Plants stand 2 to 4 feet (61 to 122 cm) tall and spread 18 to 24 inches (46 to 61 cm) wide. Give each clump room to broaden into the scene, and remember the rhizomes will keep reaching past that spread unless a basket holds the line.
When to plant
Pickerelweed keeps to the rhythm of the warm season. Set divisions or potted plants at the water in spring once frost has passed, into shoreline mud or a submerged basket, and it repays the wait with blue spikes from early summer into fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring; seed germinates best under water and may need cold stratification
- Plant: Spring, after frost, into mud at pond margins or in submerged baskets
- Harvest: Early summer into fall (about June to October)
Hardiness
USDA hardiness zones: 3–10
Temperature: down to -40°C
Troubleshooting
Pickerelweed carries no serious pests or diseases, so keeping the waterside looking its best comes down to two things: it spreads, and it must never dry out. Read what the planting is telling you below and you can restore its balance before the effect slips.
Wilting and browning from drying out or wrong planting depth
The whole effect rests on wet feet, and pickerelweed will not forgive drying out even briefly. Let the soil turn dry or merely damp, or sink the crown beneath more than a foot of water, and the fresh green look gives way to browning and standstill. Hold the soil constantly wet to shallowly submerged, and settle the depth so just 2 to 12 inches (5 to 30 cm) of water covers the crown.
Fix:
- Keep the soil constantly wet to shallowly submerged at all times
- Reset the planting depth so only about 2-12 in (5-30 cm) of water covers the crown
- Move container plants to a shallower shelf or raise them on bricks
Spreading rhizomes that crowd a small pond or container
A pond that once felt composed can lose its balance when pickerelweed reaches past its station, driven by thick rhizomes that knit dense colonies into open water and across their neighbors. The graceful solution is to seat it in a submerged aquatic basket from the outset, keeping the planting deliberate. Lift and divide the clump every 2 to 3 years, and edit back any stray shoots before the composition blurs.
Fix:
- Grow in a submerged aquatic basket or container rather than open mud to confine the rhizomes
- Lift and divide clumps every 2-3 years, discarding excess rhizome
- Pull or cut back outlying shoots to keep the colony in bounds
Minor leaf feeding from aphids, mites, or caterpillars
The clean, uncluttered look of pickerelweed rarely suffers, since it carries no serious pests or diseases and any blemish tends to be slight. A close look may turn up clusters of aphids, the faint webbing and stippling of spider mites, or leaf edges nibbled by caterpillars. A firm rinse of water clears the smallest offenders, caterpillars lift off by hand, and the planting keeps its poise as it grows past the rest.
Fix:
- Hose pests off with a strong jet of water
- Hand-pick caterpillars
- Tolerate minor damage, since this plant has no serious insect or disease problems and usually outgrows it
Toxicity
For a household that gathers near the water, this is easy company: pickerelweed is non-toxic to people and animals, and parts of it are edible. The young leaves and ripe seeds have long found a place at the table, and the plant feeds ducks and other wildlife besides. Since it lives in standing water, the single sensible caution is the usual supervision around a pond.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
A household cat can share the garden with this one in peace. A passing nibble of the leaves brings no poisoning, though the pond water alone warrants the usual watchful eye.
Dogs None
The foliage carries nothing toxic, so a dog that helps itself to a mouthful comes to no harm from the plant itself.
Horses Safe
Horses may graze the leaves along a pond edge untroubled, since none of the plant is poisonous to them.
Rabbits Safe
The tender leaves suit rabbits and hold no toxins, making this an untroubled marginal to place near a hutch or pond.
Livestock Safe
Cattle, goats, and sheep may browse it in safety. The plant is non-toxic and quietly feeds a range of grazing and wild animals.
Birds Safe
Rather than a hazard, its seeds and foliage are cherished fare for ducks and other waterfowl, with nothing to endanger backyard or wild birds.
People Safe
It is safe for people, and the young leaves and seeds are edible. Cook the young leaves as a green, and enjoy the ripe seeds raw or roasted.
No special handling precautions; the plant is safe and even edible. It lives in standing water, so normal supervision around ponds applies.
Varieties
The straight blue-flowered species is what most gardeners meet, but a couple of selections are worth folding into a planting.
'Alba'
For a cooler, more restrained palette at the water's edge, this selection lifts tall spikes of white blooms from summer into fall in place of the usual blue.
var. lancifolia
This slimmer, lance-leaved form offers a more linear silhouette than the heart-shaped foliage of the typical plant.
Companions
Pickerelweed plays well with other native marginals and pond plants that share its taste for full sun and wet ground, layering the pond edge with different heights and leaf shapes.
Plant near
Water lily (Nymphaea): A classic pond pairing: pickerelweed's vertical blue spikes at the margin complement floating-leaved water lilies in deeper water.
Arrowhead (Sagittaria latifolia): Another native marginal sharing the same shallow-water, full-sun habitat for a layered pond-edge planting.
How to propagate
There are two routes to more pickerelweed, and one settles into a planting far sooner than the other.
DivisionEasy
Spring · One growing season
Division is the surest way to bring more pickerelweed into a scheme, and the simplest. In spring, lift an established clump and part the thick rhizomes into pieces, each carrying its own roots and a shoot. The new divisions settle in and round out the planting across a single growing season.
SeedModerate
Late winter to spring · One to two growing seasons
Seed is the more patient path, sown to best effect from late winter into spring. Germination comes strongest under water, even after dry storage, and a spell of cold stratification helps it along. Allow seed-grown plants one to two growing seasons to reach a presence in the composition.
Myths
Pickerelweed is the same plant as water hyacinth and just as invasive.
These are two distinct plants with very different manners. Native pickerelweed roots in pond mud and keeps to its place, while water hyacinth floats free and has a reputation for choking waterways. The two share the family Pontederiaceae, yet pickerelweed is a well-behaved native, not the invasive floater.