Potamogeton pectinatus

RHS Plant Profile

fennel pondweed

RHS 2002

Other common names

duck grass, duck moss, potato moss, dyfrllys danheddog

Aquatic

A submerged perennial with thread-like submerged leaves and insignificant submerged flowers in summer; useful oxygenator

Position

Full sun, Partial shade

Soil Types

Loam, Sand

Max Height

Up to 10 cm

Max Spread

0.5-1 metres

Size

Time to Maturity: 5–10 years
Max Spread: 0.5-1 metres
Max Height: Up to 10 cm

Growing Conditions

Loam Sand

Moisture: Poorly–drained
pH: Acid or Alkaline or Neutral

Position

Full sun Partial shade

Aspect: South–facing or North–facing or West–facing or East–facing
Exposure: Exposed or Sheltered
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 & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Potamogetonaceae
Native to GB/Ireland: Yes
Foliage: Deciduous
Habit: Submerged
Genus: Potamogeton can be marginal or deep water aquatic perennials, with translucent submerged and leathery floating leaves, and small spikes of inconspicuous flowers held below or just above water level
Name Status: Correct

How to Grow

Cultivation

Grow in baskets of sandy loam in the bottom mud of the pond, in full sun or partial shade. See pond plants for further advice

Propagation

Propagate by stem cuttings from mid spring to early summer

Suggested planting locations and garden types

Low Maintenance

Pruning

Thin on a regular basis to keep in check

Pests

Generally pest-free

Diseases

Generally disease-free