Marsh cinquefoil

Marsh cinquefoil: how do you recognise it?

Habit

A creeping plant with ascending stems 20–40 cm tall that root at the nodes and form a loose mat.

Leaves

Pinnate, with 5–7 oblong, toothed leaflets; green above, grey-green beneath.

Flower

Star-shaped flowers 2–3 cm across with broad, dark purple-red sepals and smaller, narrow petals, in June and July.

Fruit

After flowering the flower base swells into a spongy, purple-red fruit that looks like a small strawberry.

Roots

A long, creeping rhizome that becomes slightly woody at the base.

Flowering: June–July · Plants: April–June and September · Pruning: March

Why grow it?

• Unusual dark purple-red star-shaped flowers in June and July, a colour rarely seen by the pond.
• A native plant for the acid, wet edge of a wildlife pond or bog garden.
• The flowers provide nectar for bees and bumblebees.
• Creeps through the bank with its stems, linking water and land.
• Fully hardy and little work in the right spot.

Marsh cinquefoil: where does it grow best?

• Sun or partial shade; it flowers best in full sun.
• Wet, acid to neutral soil: peat or humus-rich loam, preferably nutrient-poor.
• On the wet bank or up to 5 cm under water.
• Allow 30–40 cm between plants.

Light

Sun and partial shade

Soil type

Loam or peat

Acidity

Acid or neutral

Moisture

Wet

Size

0.4 m tall, 0.6 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Bog arum: White spathes and red berries in the same acid, wet edge.
• Bogbean: Fringed white flowers in spring, before the marsh cinquefoil flowers.
• Cotton grass: White tufts on wet, acid ground.
• Marsh fern: Light fronds as a backdrop.
• Cross-leaved heath: Pink bells in summer on the acid, wet ground beside the bank.

Marsh cinquefoil: when and how to plant it?

Plant in April–June and September.

1. Plant from April to June or in September.
2. Use a wide aquatic basket filled with low-nutrient aquatic soil, without fertiliser or compost; in a bog garden, simply plant into the acid, wet ground.
3. Plant the rhizome just below the soil, with the stems above, and firm in well.
4. Set the basket level with the water surface or up to 5 cm below it.
5. Keep 30–40 cm between plants.
6. Then top up the water with rainwater.

Care

Water

Must never dry out. Top up with rainwater: it is less happy with hard tap water.

Feeding

Not needed: it likes nutrient-poor soil.

Weeding

Keep vigorous grasses and marginals in check, or they will smother it.

Spread

The creeping stems root at the nodes; cut them back if they go too far.

Faded flowers

Leave them: the swollen fruits are attractive too.

Tip: Plant it in acid, wet soil or up to 5 cm under water and top up with rainwater: in chalky water it languishes.

Marsh cinquefoil: when to prune it?

Pruning months: March.

When: In March, before the new shoots appear. Otherwise it hardly needs pruning.

How:

• Cut last year’s dead stems back to just above the soil or water.
• Cut back creeping stems that go too far; pieces with roots can be replanted.
• Remove dead leaves from the water.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In April–May, cut off a piece of creeping stem with roots and replant it elsewhere in wet soil or an aquatic basket.

Layering

The stems root by themselves at the nodes: in spring, cut a rooted piece free and plant it separately.

Seed

Sow in autumn in a pot of wet, acid soil and leave the pot outdoors over winter.

Marsh cinquefoil: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C: no protection needed.
• The foliage dies back in autumn; the rhizome overwinters in the wet soil.
• Leave the old stems until March as shelter for insects.

Diseases and pests

• Drying out: Brown, withered leaves in a dry summer. Keep the soil wet with rainwater.
• Pale leaves: Yellowish foliage in chalky soil or hard water. Use rainwater and a more acid mix.
• Crowded out: Grasses and vigorous marginals push it out. Weed, and keep strong neighbours in a basket.
• Few flowers: Too much shade or too rich a soil. Give more sun and do not feed.

Through the year

• March: Cut back old stems.
• April: Plant or divide.
• May: Plant. Keep strong neighbours in check.
• June: In flower. Top up with rainwater.
• July: In flower. Keep the soil wet.
• August: The fruits swell. Top up the water in dry spells.
• September: Plant. Collect seed.
• October: Sow in a pot outdoors.
• December: Rest.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• It is also known as Potentilla palustris: it is related to the cinquefoils and to the strawberry.
• Its Dutch name, ‘water strawberry’, refers to the swollen, spongy flower base after flowering, which looks like a small strawberry.
• Because fens and marshes have been drained, it has become rare in Flanders.