Ornamental · Ranunculaceae
Marsh Marigold
Caltha palustris
Where the ground stays wet to soggy, marsh marigold lifts cupped, waxy gold flowers over glossy green leaves before almost anything else opens.
Full sun
Every 1–3 days
USDA 3–7
8–24 in · 20–61 cm
Overview
Marsh marigold opens some of spring's first flowers, cupped and waxy and a deep buttery gold that catches the light along ponds, streams, and boggy ground. Each bloom is built from broad, rounded, petal-like sepals in the manner of the buttercup family, and they sit above mounds of dark, glossy, rounded, heart-shaped leaves.
The leaves are the plant's steady frame: thick, deep green, and shining, with a rounded to kidney shape and a scalloped edge, held on succulent stems that rise from a clump at the water's edge. The whole plant grows in constantly moist to wet, humus-rich soil or shallow standing water, and the wet sheen on leaf and stem is part of how it looks up close.
Come summer the picture changes. The bright gold fades, the glossy leaves yellow and slacken as the plant slips into summer dormancy, and the clump dies back before pushing up firm new growth the next spring. The fresh tissue is juicy and full of irritant sap, so the plant asks for 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 water's edge, with very little needed beyond keeping the glossy foliage from ever drying out.
Light
Marsh marigold takes full sun to part shade and opens the most cupped gold flowers where the light is strong. In hot-summer regions a little afternoon shade helps, since it slows the slide into summer dormancy and keeps the glossy leaves green and firm for 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 succulent leaves and stems should never dry out. Let the ground go dry after flowering and the plant often yellows early into summer dormancy.
Soil
It roots into wet, humus-rich, mucky soil of the kind that gathers at a pond edge, and it will even stand in shallow water. A pH anywhere from 5.5 to 7.5 suits it, so the soil reaction is rarely worth worrying about.
Temperature
Cold does not touch it. 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 yellow the foliage into early dormancy.
Humidity
It thrives in damp air, which comes with the wet, marginal spots where its leaves stay glossy. High humidity around the foliage suits it, so nothing extra is needed when it sits near water.
Feeding
Feeding is light work. As the first glossy growth pushes up 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 the faded gold flowers and clear the yellowing leaves as the plant dies back, and remember that summer dieback is normal, with firm new growth returning from the crown the following spring.
Repotting
Divide and refresh clumps every 2 to 3 years, or sooner if flowering thins, 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, building a low, leafy mound of rounded foliage at the water's edge.
When to plant
Marsh marigold runs on an early calendar. It breaks dormancy and unfurls its glossy leaves and waxy gold cups in early to mid spring, one of the first plants to bloom, then often yellows and 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 show first in the leaves and trace back to one thing: soil that dried out. Learn to read a normal summer yellowing against genuine trouble and you will rarely need to step in. Match the look of the foliage below before you act.
Plant wilts, fades, or never comes back
When the leaves go limp and the whole clump sags, the cause is nearly always dry soil. Marsh marigold is a bog plant whose roots want to stay constantly moist to wet, and dry ground shrivels the foliage and can finish the plant. Set it at a pond margin, bog garden, or rain garden, water often to keep the ground saturated, and lay mulch over the roots to hold the wet 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
When the glossy green leaves fade to yellow and soften in summer, that is summer dormancy, not sickness. Once the last spring flower closes, marsh marigold pulls back, and a dry or hot-summer spot browns the foliage sooner. Leave the plant where it stands, keep the soil wet, and lift away the limp yellow leaves after the crown has settled 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
Chalky white film or rust-colored spots on the foliage
A chalky white dusting across the glossy leaves signals powdery mildew, and raised orange-brown pustules signal rust. Both take hold when the air hangs still in a crowded clump. Pull off the coated and spotted leaves, thin the clump so air slips between the stems, and keep water off the foliage late in the day. Past these two, the plant carries no real pest or disease.
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 that seeps from the juicy leaves and stems when they 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, sappy 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 into the fresh, sap-filled leaves meets a sharp irritant and usually backs off fast. Watch for drooling, pawing at the mouth, vomiting, and loose stool.
Dogs Toxic
Chewing the glossy leaves or the hollow 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, juicy plant burns the mouth and turns the stomach, so a grazing horse rarely takes more than a bite. Once it dries brittle 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, sappy plant well out of reach.
Livestock Toxic
For grazing cattle, along with goats and sheep, the raw and sappy plant blisters the lips and turns the gut, so the bitter flavor tends to stop them cropping much. Dried brittle in hay, the leaves and stems lose that burn and pose no trouble.
Birds Toxic
Treat it as unsafe around birds. The crushed leaves and stems release 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 the succulent stems, 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 shift the look of the flowers. These are the two worth knowing.
'Flore Pleno' ('Multiplex')
A double-flowered form whose densely packed petal-like sepals build full, rounded, pompon-like golden-yellow blooms.
var. alba
A white-flowered form whose clean white petals ring a small yellow center in place of the usual solid gold.
How to propagate
You can make more marsh marigold by splitting a clump or sowing seed, and division is much the faster and surer of the two.
DivisionEasy
Early spring or late summer after flowering · One growing season
Division is the easiest way to make more plants. Lift an established clump in early spring or late summer once flowering is done, tease the fibrous crown apart into pieces, and set each one back in wet ground. Kept soaking wet, the divisions take root 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, since a cold winter spell breaks the seed's dormancy and starts it sprouting. New seedlings take several months to a year to bulk up, and on permanently wet ground the marsh marigold often self-seeds and scatters fresh plants on its own.
Myths
Marsh marigold and the true cowslip are a single plant under two names.
They carry the old name cowslip in common 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 the botanical name is what settles it.
Foragers can gather marsh marigold and eat its greens raw without harm.
Raw, the juicy green tissue is a buttercup-family irritant loaded with protoanemonin that can blister the mouth. Only the young leaves and tight flower buds, boiled thoroughly, have a history of being eaten, since cooking breaks the toxin down. No part is safe to eat raw.