Join the RHS

Find a plant – quick search

Where are Plant Finder & Plant Selector?

Where are Plant Finder & Plant Selector?

We have combined these two powerful search tools into a single Find a Plant service searching over 250,000 plant records.

Virtually all of the features of the old searches are still available and in addition we have added several new features to create a more comprehensive and user friendly search experience.

When using this search

  • If you enter just a plant name, you will see results from the old RHS Plant Finder and Selector databases
  • If you select any attributes with or without a plant name, you will see a much narrower selection of results taken only from the old RHS Plant Selector database. These plants will have a lot more details displayed including an image.
  • Our Botanical team are working hard to increase the number of plants with detailed information.

Search by plant name, key attributes or both to find plant details and a list of suppliers.

 
  • AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases
Need more criteria? Try an advanced search
Back to search results

Caltha polypetala Hochst. ex Lorent

giant marsh marigold

© RHS
Sold by 7 nurseries

  • Other common names giant marsh marigold

  • Synonyms Caltha palustris subsp. polypetala

  • Family Ranunculaceae

  • Genus Caltha are rhizomatous herbaceous perennials with simple, usually heart-shaped leaves and cup-shaped yellow or white flowers in early spring

  • Details C. polypetala is a herbaceous perennial, up to 60cm high and 90cm wide, spreading by rooting stems across ground or across water. It has rounded green leaves, the basal leaves up to 10cm across, the stem leaves fewer and smaller, and shining, bright golden yellow flowers, up to 5cm across, from early spring to summer

  • Plant range Asia

Characteristics

  • Foliage Deciduous

  • Habit Clump-forming

  • Hardiness

    Hardiness ratings

    All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

    • H1a - Under glass all year (>15C)
    • H1b - Can be grown outside in the summer (10 - 15)
    • H1c - Can be grown outside in the summer (5 - 10)
    • H2 - Tolerant of low temperatures, but not surviving being frozen (1 to 5)
    • H3 - Hardy in coastal and relatively mild parts of the UK (-5 to 1)
    • H4 - Hardy through most of the UK (-10 to -5)
    • H5 - Hardy in most places throughout the UK even in severe winters (-15 to -10)
    • H6 - Hardy in all of UK and northern Europe (-20 to -15)
    • H7 - Hardy in the severest European continental climates (< -20)

    H7

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing or East-facing

  • Exposure Sheltered or Exposed

Soil

  • Loam

    Loam

  • Clay

    Clay

  • Sand

    Sand

  • Chalk

    Chalk

  • MoisturePoorly-drained

  • SoilLoam, Clay, Sand, Chalk

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Plant from spring to autumn in full sun, in deep, rich organic soil, at the water's edge or in shallow water up to 15cm deep; mulch annually to conserve moisture

Propagation Propagate by seed, sown fresh in late summer in a cold frame, making sure that the compost does not dry out, or by division in spring

Suggested planting locations and garden types Low Maintenance Cottage & Informal Garden

How to care

Pruning No pruning required, though the stems may be cut back after flowering

Pests Generally pest free

Diseases May be affected by powdery mildews and rust diseases

Did you find the information you were looking for?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.