Lesser pond-sedge

How to recognise it

Habit

Robust, upright sedge of 60–150 cm that forms extensive, dense stands from long rhizomes.

Leaf

Bluish green to grey-green, 7–15 mm wide, with rough, razor-sharp edges; the lower leaf sheaths are brownish.

Flower

At the top 2–3 dark brown male spikes, below them 3–5 cylindrical female spikes of 2–5 cm, with three stigmas per flower; in May–June.

Stem

Sharply three-angled, rough on the edges, solid and without nodes.

Fruit/Seed

Small, oval, faintly veined utricles with a short, two-toothed beak; ripe in July–August.

Confusion with

Greater pond-sedge is even larger, with broader leaves, thicker spikes and male spikes with long-pointed scales; its utricles are inflated with a long beak. Slender tufted-sedge has two stigmas and flattened utricles. Reed sweet-grass is a grass with round stems that have nodes.

Flowering: May–June · Pruning: March

Why grow it?

• Forms dense marginal stands that hold the soil of ditch sides and banks together.
• Birds such as the reed bunting and the moorhen find shelter and nest sites in its tall, dense stands.
• Dragonflies and damselflies perch on its sturdy leaves; beetles, spiders and snails live among the stems.
• Bluish-green leaves that look fresh all summer and stay standing, straw-coloured, in winter: structure at the water’s edge.
• Like reed it takes up nutrients from the water; sedges are sometimes used in reed-bed filters.

Lesser pond-sedge: where does it grow best?

• In the wild: banks of ditches, streams, rivers and ponds, marshes, tall-herb fen and alder carr.
• Sun to partial shade; also tolerates quite a lot of shade under alders and willows.
• Wet to very wet, fertile soil; tolerates shallow water of 0–20 cm and flooding.
• In the garden: only beside a large pond, a ditch or in a wet corner where it may spread. In a small pond, plant it in a sturdy basket.

Goes well with

• Yellow iris: Large yellow flowers in May–June on the same bank.
• Meadowsweet: Creamy, fragrant plumes in summer.
• Purple loosestrife: Purple flower spikes in July–August for bees and butterflies.
• Marsh marigold: Glossy yellow in early spring, before the sedge grows up.
• Yellow loosestrife: Yellow flowers in summer; the yellow loosestrife bee collects oil and pollen from it.

Lesser pond-sedge: when and how to plant it?

1. Buy plants from a nursery for aquatic or native plants; never dig up clumps in the wild.
2. Plant from April to September in wet soil or in water up to 10–20 cm deep.
3. Allow 2–4 plants per m² for a quick marginal fringe; they soon join up.
4. In a lined pond, plant in a sturdy basket or container so that the rhizomes cannot take over the whole bank.
5. Keep the soil wet at all times in the first year.
6. Wear gloves when planting: the leaf edges cut.

Care

Watering

Must always stand wet; top up the pond with rainwater in dry summers.

Feeding

Never: fertiliser enriches the water and encourages algae.

Mowing

Cut or mow away dead leaves in late February–March; in large stands, leave part uncut each year.

Spreading

Each spring or in September, cut back the edges with a sharp spade if it spreads too far.

Gloves

Always work with gloves and long sleeves: the leaf edges are razor-sharp.

Tip: In a small pond always plant lesser pond-sedge in a sturdy basket or container: you get the handsome foliage without the rhizomes taking over the whole bank.

Pruning and mowing

Pruning months: March.

When: Late February to late March, before new leaves appear.

How:

• Cut or mow the dead leaves down to 10–15 cm above the ground or water.
• Remove the cut leaves from the pond so the water is not enriched.
• In a large stand, leave a section uncut each time: insects overwinter there.

Caution: Do not mow or cut between April and July: birds nest in the dense vegetation then.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In April–May cut off pieces of rhizome with a few shoots and replant them elsewhere in wet soil.

Seed

Ripens in July–August; sow fresh on wet, bare soil. Growing from seed is slow; division is quicker.

Lesser pond-sedge: how does it get through the winter?

Hardy to −30 °C.

• Most leaves turn straw yellow to brown; some stay green.
• Fully hardy, to about −30 °C.
• The dense, dead growth offers shelter to insects, spiders and small mammals.

Diseases and pests

• Spreading: It can choke a small pond completely. Plant in a basket or cut back the edges every year.
• Cutting leaves: Children and pets can cut themselves on the leaf edges. Do not plant it along a path or play area.
• Silting up: Dead leaves build up and fill the pond. Remove the cut leaves every spring.
• Drying out: Where the ground dries out in summer, the leaves wither. Choose a spot that stays wet.

Through the year

• March: Cut away dead leaves and lift them out of the pond.
• April: New shoots. Plant and divide.
• May: Flowering: dark brown male spikes with pale anthers.
• June: In flower; birds nest in the stands.
• July: Seed ripens.
• September: Cut back the edges where it has spread too far.
• November: Leaves turn straw-coloured; leave them as winter shelter.

Did you know?

• Acutiformis means ‘shaped like acuta’: the plant resembles slender tufted-sedge, Carex acuta.
• The word sedge, like the Dutch zegge, goes back to an old word related to ‘cutting’, after the sharp leaf edges.
• A rhyme helps tell them apart: ‘sedges have edges, rushes are round, grasses have nodes’.