Ornamental · Pontederiaceae
Pickerelweed
Pontederia cordata
A forgiving 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 is a native aquatic that settles happily along the edges of ponds, ditches, and slow streams across much of North America. It roots down in the mud at the water's edge and holds its leaves and flower spikes up above the surface, which is all a gardener means by an emergent marginal. Glossy, heart-shaped leaves make up the base, and from early summer into fall it lifts soft spikes of violet-blue flowers for you to enjoy.
This is a plant that gives back. The flowers welcome bees and other pollinators, while ducks and waterfowl feed on the seeds and foliage. As a hardy perennial it takes winters in stride from zone 3 all the way to zone 10, dying back in fall and returning from the rhizome each spring, so you do not have to replant it.
Really only two things matter, and both are easy to manage once you know them. The roots need to stay constantly wet to shallowly submerged, since this is a wetland plant that must not dry out, and the same eagerness that fills a pond edge with bloom will wander if you let it. Grow it in a basket where space is tight and it stays a generous, well-mannered clump you can be proud of.
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 slip the rhizomes into a basket so they stay put and don't take over.
Light
Pickerelweed blooms its best in full sun, and that is where you will be rewarded with the most spikes and the sturdiest growth. It will get along in partial shade too, so do not fret if your spot is a little shadier, though expect fewer flowers and a looser, leggier plant.
Water
Since this is a true wetland plant, its roots need to stay constantly wet to shallowly submerged and never dry out. Settle it into 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 water's edge. Just take care not to plant deeper than roughly 12 inches (30 cm), since too much water over the crown can be too much for it.
Soil
Give it rich organic loam or mud that stays constantly wet to submerged and it will feel right at home. It is easygoing about pH, happy anywhere from 6.0 to 8.0, so most pond mud will suit it without any fuss on your part.
Temperature
Pickerelweed is wonderfully hardy, riding out everything from -40°F (-40°C) in winter dormancy up to around 100°F (38°C) in summer heat. That range spans zones 3 through 10, so across most of the country it simply overwinters in place and comes back for you.
Humidity
Living in or beside water, it never lacks moisture in the air, so humidity is one less thing for you to manage. The high humidity at a pond edge is exactly the kind of spot where it feels its best.
Feeding
It asks for very little feeding and looks after itself for the most part. If you would like to encourage more growth, work an aquatic plant tablet into the soil during the spring-through-summer season, but keep it gentle, because this plant does just fine on its own.
Pruning
Upkeep here is truly light. Snap off the spent flower spikes as they finish through the season, then cut back and clear away the old, dead foliage in late fall or early spring before the new growth stirs.
Repotting
About every 2 to 3 years, lift the plant to divide and freshen up a crowded clump. It will tell you when it is ready: rhizomes bulging the basket, smaller leaves with fewer flowers, and the plant heaving itself up out of its pot.
Size & spacing
Plants grow to 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 widen, and keep in mind the rhizomes will keep reaching past that spread unless a basket gently holds them in.
When to plant
Pickerelweed keeps to the warm season, so there is no rush. Set divisions or potted plants out in spring once the frost has passed, into mud at the pond margin or a submerged basket, and it will thank you with blue spikes from early summer until 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
Take comfort in this: pickerelweed has no serious pests or diseases, so nearly all of its troubles come down to two easy-to-read things, that it spreads and that it must never dry out. Match what you see below and you can put it right well before it wanders too far or fades.
Wilting and browning from drying out or wrong planting depth
The one thing this wetland plant truly cannot forgive is drying out, so if the soil ever goes dry or only damp, or if the crown ends up under more than a foot of water, you will see it brown and stall. The good news is that this is easy to put right. Keep the soil constantly wet to shallowly submerged, and gently reset the depth so just 2 to 12 inches (5 to 30 cm) of water sits over the crown, and it will pick itself back up.
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
If your pickerelweed starts pushing past where you planted it, take heart, because this is simply the plant doing well. Its thick rhizomes travel through open mud and build dense colonies that lean into open water and over their neighbors. The easy fix is to give it a submerged aquatic basket from the day you plant, then lift and divide the clump every 2 to 3 years and trim back any wandering shoots, and it will settle right back into a tidy, generous clump.
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
You can relax here, because pickerelweed carries no serious pests or diseases and anything you spot is almost always minor. Keep a friendly eye out for little clusters of aphids, the faint webbing and speckling of spider mites, or leaf edges nibbled by caterpillars. A firm spray of water knocks the small pests loose, caterpillars come off by hand, and the plant will happily grow past the rest on its own.
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
Here is a reassuring note for pet owners and gardeners alike: pickerelweed is non-toxic to people and animals, and parts of it are even edible. The young leaves and ripe seeds have long been on the menu, and the plant is a valued food for ducks and other wildlife. Since it grows in standing water, the only real thing to mind is the usual supervision around a pond.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
You can rest easy with cats around this one. A curious nibble of the leaves will not poison them, though the pond water itself is reason enough to keep a normal eye out.
Dogs None
There is nothing toxic in the plant, so if your dog grabs a mouthful of foliage, it is in no danger from the pickerelweed itself.
Horses Safe
Feel free to let horses graze the leaves along a pond edge, since none of the plant is poisonous to them.
Rabbits Safe
The soft leaves suit rabbits just fine and hold no toxins, so this makes a worry-free marginal near a hutch or pond.
Livestock Safe
Cattle, goats, and sheep can browse it without any worry. The plant is non-toxic and even feeds a whole range of grazing and wild animals.
Birds Safe
Rather than a hazard, the seeds and foliage are a treasured meal for ducks and other waterfowl, with nothing to trouble backyard or wild birds.
People Safe
Good news at the table too: the young leaves and seeds are edible. Cook the young leaves like 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
Most pickerelweed you will find is the straight blue-flowered species, but a couple of selections turn up that are worth getting to know.
'Alba'
If you would rather have soft white than the usual blue, this selection sends up tall spikes of white blooms from summer into fall.
var. lancifolia
This gentle variation wears slimmer, lance-shaped leaves in place of 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 ways to make more pickerelweed, and happily one is far quicker and simpler than the other.
DivisionEasy
Spring · One growing season
Division is the friendliest and most dependable way to make more pickerelweed, so start here if you are new to it. Come spring, lift an established clump and part the thick rhizomes into pieces, keeping roots and a shoot on each one. Those new divisions take hold and fill out over a single growing season, so patience is barely needed.
SeedModerate
Late winter to spring · One to two growing seasons
Seed asks for a little more patience and does best sown from late winter into spring. Germination is strongest under water, even after dry storage, and a stretch of cold stratification gives it a helpful nudge. Allow seed-grown plants one to two growing seasons to reach a good size, and they will get there.
Myths
Pickerelweed is the same plant as water hyacinth and just as invasive.
You can set that worry aside, because these are two different plants. Your native pickerelweed roots itself in pond mud and stays where it is put, while water hyacinth floats free and has earned its reputation for choking waterways. They do share the family Pontederiaceae, but pickerelweed is a well-behaved native, not the invasive floater.