Ornamental · Ranunculaceae
Marsh Marigold
Caltha palustris
Plant it where the ground stays wet to soggy, and marsh marigold lights up the water's edge before almost anything else blooms.
Full sun
Every 1–3 days
USDA 3–7
8–24 in · 20–61 cm
Overview
Marsh marigold is one of spring's first big splashes of gold, opening cupped yellow flowers at the edge of ponds, streams, and boggy ground while most of the garden is still waking up. It belongs to the buttercup family, and you can see the family resemblance in those glossy petals and the rounded, heart-shaped leaves below them.
This is a plant with one firm demand: it wants its feet wet. A native of wet meadows and marshes, it thrives in constantly moist to wet, humus-rich soil or even shallow standing water, which makes it a natural fit for a pond margin, bog garden, or rain garden. Give it that and it asks for almost nothing else.
It is tough and long-lived, hardy through bitter winters, and easy to grow as long as the soil never dries out. After the spring show, it often slips into summer dormancy and dies back, only to return the next spring. The whole plant is an irritant when fresh, so it earns a little caution around pets and children.
Care
The short version: full sun to part shade and soil that stays wet to soggy all season, in rich, mucky ground at the edge of water, with very little fuss beyond keeping it from ever drying out.
Light
Marsh marigold takes full sun to part shade and flowers best with plenty of light. In hot-summer regions a little afternoon shade helps, since shade slows the slide into summer dormancy and keeps the foliage going longer.
Water
This is the part that matters most. The roots need to stay constantly moist to wet, in saturated soil or even shallow standing water, and the plant should never dry out. Let the ground go dry after flowering and it often drops early into summer dormancy.
Soil
Grow it in wet, humus-rich, mucky soil of the kind you find at a pond edge, and it will even cope with shallow standing water. A pH anywhere from 5.5 to 7.5 suits it, so the soil reaction is rarely worth worrying about.
Temperature
Cold is no problem at all. The plant is hardy down to about -40°F (-40°C) and handles heat up to roughly 86°F (30°C), though hot summers tend to push it into early dormancy.
Humidity
It likes things damp, which comes naturally in the wet, marginal spots it prefers. High humidity around the foliage suits it, so no extra effort is needed when it is sited near water.
Feeding
Feeding is light work. As growth starts in spring, give it a single helping of balanced fertilizer or work in some rich compost, and that carries it through the season.
Pruning
There is little to cut. Snip off spent flowers and clear away yellowing leaves as the plant dies back, and remember that summer dieback is normal and the crown will push up fresh growth the following spring.
Repotting
Divide and refresh clumps every 2 to 3 years, or sooner if flowering drops off, the roots fill the pot, or the crown starts lifting above the soil. Keep any divisions wet while they settle.
Size & spacing
Plants reach about 8 to 24 inches (20 to 61 cm) tall and spread to roughly 12 to 18 inches (30 to 46 cm) across, forming a tidy mound at the water's edge.
When to plant
Marsh marigold runs on an early calendar. It breaks dormancy and flowers in early to mid spring, one of the first plants to bloom, then often dies back through summer. Plant it in spring or fall in wet ground, and sow seed fresh in late summer to fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Sow fresh seed in late summer to fall; cold stratification improves germination
- Plant: Spring or fall, in wet soil or pond margins after frost
- Harvest: Early to mid spring (April to June), one of the earliest spring bloomers
Hardiness
USDA hardiness zones: 3–7
Temperature: down to -40°C
Troubleshooting
Marsh marigold has few real problems, and most of them trace back to one thing: soil that dried out. Learn to tell normal summer dieback from genuine trouble, and you will rarely need to step in. Match what you see below before you act.
Plant wilts, fades, or never comes back
Almost every time, the cause is dry soil. Marsh marigold is a bog plant that needs its roots constantly moist to wet, and a spell of dry ground will set it back or kill it outright. Move it to a pond margin, bog garden, or rain garden, water often enough to keep the soil saturated, and mulch to hold that moisture in.
Fix:
- Move or replant at a pond margin, bog garden, or rain garden where soil stays wet
- Water frequently to keep the soil saturated
- Mulch to retain moisture
Leaves yellow and die back in summer
This is summer dormancy, not a sickness. Once marsh marigold finishes its spring bloom it pulls back, and dry or hot-summer sites push it under all the sooner. Leave the plant where it is, keep the soil wet, and tidy the withered leaves once the crown has gone quiet for the year.
Fix:
- Leave the plant in place and let foliage die back naturally
- Keep the soil wet to prolong the foliage and reduce stress
- Tidy away yellowed leaves once they have withered
White powder or rusty spots on the leaves
A white film points to powdery mildew, while orange-brown pustules mean rust. Both take hold when air sits still around a crowded clump. Strip off the marked leaves, open the plant up so air can move through it, and stop wetting the foliage late in the day. Beyond these two, the plant has no real pest or disease worries.
Fix:
- Remove and dispose of affected leaves
- Improve air circulation around the clump
- Avoid wetting foliage late in the day
Toxicity
The whole plant is toxic when fresh. As a member of the buttercup family it holds protoanemonin, an irritant released when the leaves or stems are crushed or chewed, and it can blister the mouth and skin and upset the stomach. The bitter, burning taste usually stops an animal from eating much, but keep the fresh plant away from pets, livestock, and children all the same.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Toxic
A cat that bites the fresh plant gets a mouthful of irritant sap and usually backs off fast. Watch for drooling, pawing at the mouth, vomiting, and loose stool.
Dogs Toxic
Chewing the leaves or stems leaves a dog drooling and off its food, often with vomiting or diarrhea soon after. The acrid, blistering taste keeps most dogs from eating much.
Horses Toxic
The fresh plant burns the mouth and turns the stomach, so a grazing horse rarely takes more than a bite. Once it dries in hay the protoanemonin breaks down and the danger is gone.
Rabbits Toxic
Not safe to offer. The same protoanemonin that irritates other animals blisters a rabbit's mouth and upsets its gut, so keep the fresh plant well out of reach.
Livestock Toxic
Cattle, goats, and sheep can blister their lips and suffer stomach upset from the raw plant, though the bitter taste usually stops them grazing it. Plants dried into hay lose their bite and pose no problem.
Birds Toxic
Treat it as unsafe around birds. The crushed plant releases the same caustic compound that troubles mammals, so there is no reason to let a bird peck at it.
People Caution
Never eat any part raw. The fresh sap can blister the mouth and skin, so wear gloves when you cut it, though thorough boiling breaks down the toxin and the cooked young leaves and buds have long been eaten.
The raw plant is toxic and irritant: the same protoanemonin found in buttercups and clematis. Cooking (boiling) destroys the protoanemonin, and cooked young leaves and flower buds have historically been eaten - never eat any part raw. The sap can irritate skin, so wear gloves when handling or cutting.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Beyond the wild golden form, a couple of selections turn up in gardens. These are the ones worth knowing.
'Flore Pleno' ('Multiplex')
A double-flowered form that packs in extra petal-like sepals for full, rounded golden-yellow blooms.
var. alba
A white-flowered form that trades the usual gold for clean white petals around a yellow center.
How to propagate
You can make more marsh marigold by splitting a clump or starting from seed, and division is much the faster and surer of the two.
DivisionEasy
Early spring or late summer after flowering · One growing season
The simplest way to make more plants. Lift an established clump in early spring or late summer once flowering is done, split the crown into pieces, and replant each one. Keep the divisions soaking wet and they settle in over a single growing season.
SeedModerate
Sow fresh seed in late summer to fall · Several months to a year; may self-seed in suitable wet sites
Seed takes more patience. Sow it fresh in late summer to fall, because a cold winter spell breaks dormancy and gets it sprouting. New plants need anywhere from several months to a year to find their feet, and on permanently wet ground the marsh marigold often self-seeds without any help.
Myths
Marsh marigold and true cowslip are the same plant.
They share the old name cowslip but belong to different families. Marsh marigold is Caltha palustris in the buttercup family, while true cowslip is Primula veris among the primroses. The shared common name is the only thing they have in common, so go by the botanical name when it matters.
Marsh marigold is a safe wild green to forage and eat.
Raw, it is a buttercup-family irritant loaded with protoanemonin that can blister the mouth. Only the young leaves and flower buds, boiled thoroughly, have a history of being eaten, since cooking breaks the toxin down. No part is safe to eat raw.