Wetland and water gardens

These are gardens (or areas in a garden) that are permanently wet or that alternate between being boggy and inundated. Some gardens may ‘naturally’ come with a boggy area, often in a low-lying spot at the bottom of a slope; this can be enhanced by waterproofing or concreting the bottom of the pond if you want a larger, deeper or more permanent area for water to collect. In others, a water garden or boggy spot can be created by digging out soil in an area that is already low-lying so that rainfall will drain into it naturally. See below for some useful resources on creating a water or wetland garden.

Naturally dry areas, such as this slope below a building, can be used for water gardens, but they require careful construction to prevent leakage. Image by Emma Rooksby.
A water feature, whether a permanent pool or a boggy area that occasionally fills with water, can create a place of peace and calm in a garden, as well as being a haven for wildlife. Choosing local plant species increases your chances of attracting native fauna such as frogs and water dragons.
This Water Dragon turned up in a garden that contains several small ponds and boggy areas. Here it is enjoying  a spell in the sun. Image by Keith Horton.

Large-scale landscaping can also make effective use of low-lying and flood-prone land to create a water garden. For example, the University of Wollongong's Innovation Campus in Fairy Meadow has created a natural-looking wetland area.
Large low-lying areas have huge potential to create large ponds or recreate natural wetlands. Image by Mithra Cox, reproduced under CC BY-NC 2.0
Along the edges of larger water gardens, different plants are used depending on how much soil moisture and waterlogging they will tolerate. This also creates a range of different textures. Image by Emma Rooksby.
Some plants to consider include:
Floating plantsNotes
Entire Marshwort (Nymphoides geminata)Hardy aquatic perennial with water lily shaped leaves and very attractive fringed, star-shaped yellow flowers extending above the water.
Swamp Lily (Ottelia ovalifolia)Submerged plant with broad floating leaves and beautiful white flowers held just above the water surface. Grows in full sun or partial shade, in shallow to moderately deep water. Provides cover for tadpoles.
Pacific Azolla (Azolla filiculoides)Tiny floating water fern with overlapping leaves. May need some management to prevent it covering the entire pond surface.
Water Ribbons (Cycnogeton procerum, also C. microtuberosum and C. striatum)Attractive aquatic plant for full or partial shade in permanent water; glossy leaves floating or erect, 50cm or more. Leaves, seeds and tubers are eaten by waterbirds, attracts butterflies and other insects and provides fish habitat.
Sedges and rushes
Tall Sedge (Carex appressa)
Hardy grass-like sedge to 1m with spiralling flower-heads, for full sun to full shade, prefers moist soil but is fairly drought tolerant. Suitable for pond edges and boggy areas that may dry out periodically. Provides good shelter for small frogs. Attracts butterflies and is a wombat food plant.
Tassel Sedge (Carex fascicularis)Hardy, attractive sedge with bright green tassels, 1m x 1m, for sunny position or shade, may be drought tolerant but prefers regular water. Suitable for ponds and boggy spots. Butterfly food plant.
Common Rush (Juncus usitatus)Clumping rush with cylindrical leaves, to 1m tall, grows in full sun to partial shade. Suitable for boggy areas that may dry out periodically. Provides shelter for small frogs when planted closely in groups. Provides seed and shelter for small birds and is a butterfly food plant.
Tassel Rush (Baloskion tetraphyllum subsp. meiostachyum)Distinctive bright green, feathery-looking rush to 1.2m, for full sun to shade in moist soils or shallow water. Hardy and suitable for boggy spots and shallow ponds. Provides seed for birds and attracts butterflies.  Used by Jervis Bay Tree Frog.
Grey Rush (Lepironia articulata)Has long, round grey stems up to 2m tall. Its height and grey colour make it stand out from other freshwater plants. Suitable for wetland edges and boggy spots.
Common Spike-rush (Eleocharis acuta)A perennial with unbranched stems and leaves like sheaths, up to 60cm tall. Suitable for boggy spots and small ponds.
Tall Spike-Rush (Eleocharis sphacelata)Spreading, tall perennial to 2m with pale green stems and attractive flower spikes for full sun and partial shade, preferably in deeper water.  Suitable for large wetland areas, ponds and dams. A good basking plant for all green tree frogs. Also provides shelter, nest sites and food for waterfowl and other wildlife.
Red-Fruited Saw Sedge (Gahnia sieberiana)Tall, arching, sharp-leaved sedge to 2m, with dark brown, feathery flowerheads. Grows well in moist soils and tolerates water-logging, full sun or shade, grows well in pots. Suitable for boggy areas. Provides excellent shelter sites for small tree frogs and attracts seed-eating birds and butterflies.
Jointed Twig Rush (Baumea articulata)Attractive water plant with dark green, cylindrical leaves and graceful, weeping flower heads growing to 2m in full sun in deeper water. Suitable for ponds and water gardens. Provides shelter for frogs when planted closely in groups and seed and shelter for waterbirds and may attract butterflies.
Mat Rush (Lomandra longifolia)Clumping, hardy strap-leaved plant to 70cm, with sharpened leaf tips.Good for exposed and coastal gardens on any soil in sun or shade. Suitable for drier areas around the edge of boggy spots or water bodies. Excellent habitat for small frogs, and attracts seed and insect-eating birds and butterflies, provides shelter and nesting sites for birds and is a wombat food plant.
Common Reed (Phragmites australis)Tall, erect grass to 2m, with handsome, feathery flower heads forming dense stands in marshy ground in fresh or brackish water. Suits sunny or semi-shaded position. Fast and wide-spreading so may require containment in pots. Suitable for boggy areas and ponds. Provides habitat for birds and insects such as butterflies.
Herbs and groundcovers
Yellow Marsh-flower (Liparophyllum exaltatum)Broad, fleshy leaved herb with prominent yellow flowers on tall stems, for full sun or partial shade in wet or waterlogged areas. Suitable for bog and pond, and can grow in deeper water. The leaves are eaten by herbivores such as Swamp Wallabies.
Water Plantain (Alisma plantago-aquatica)Broad-leaved herb, with tall flower stems to 1m during summer, found in full sun or part shade; may become dormant in very hot weather and die back in winter. Suitable for ponds or bog areas. The fruits and leaves are eaten by wildlife.
Woolly Frogmouth (Philydrum lanuginosum)Tufted succulent herb to 1.5m, with showy yellow flowers in full sun or shade in moist or wet soil in a warm position, may be drought tender, flowers opening over a period of several weeks. Suitable for boggy areas and ponds. Provides food and cover for birds, frogs and other animals.
Native Violet (Viola hederacea)Creeping, hardy, round-leaved groundcover forming carpets in moist shady places groundcover with attractive purple and white flowers. Suitable for damp and boggy areas.
Provides shelter for small skinks and possibly small frogs. Also a butterfly food plant.
Lawn Water Pennywort (Hydrocotyle peduncularis)Hardy, vigorous groundcover with lobed leaves suitable for shady areas. Won’t tolerate pedestrian traffic. Suitable for boggy spots.
Gotu Kola (Centella asiatica)Hardy creeping groundcover with rounded leaves useful for underplanting amongst taller plants in damp areas. May withstand some drying out as well as inundation for short periods. Suitable for boggy areas.
Swamp Goodenia (Goodenia paniculata)Spreading tufted groundcover to 30cm with yellow flowers. Prefers moist sunny areas, but will tolerate some shade and is drought tolerant. Suitable for boggy areas and pots. Attracts butterflies, native bees and small insects which provide food for frogs.
Slender Knotweed (Persicaria decipiens)Very common, dense groundcover herb to 1m, with striking pink, pendulous flowerheads. Suits moist position in sun or semi-shade. May be drought tolerant. Suitable for boggy areas. Provides cover for ground frogs and attracts seed-eating birds such as finches.
Spotted Knotweed (Persicaria strigosa) Dense groundcover to 1m, with striking white flowerheads. Suits moist or submerged position, in sun or semi-shade. Suitable for boggy areas and ponds or water gardens. Provides good cover for frogs such as Striped Marsh Frog and Peron’s Tree Frog and is likely to attract seed-eating birds.

Even in truly dry areas, a water garden can be created using a watertight container such as this repurposed  bathtub. Image by Emma Rooksby.

Many water plants have specific growing requirements and involve techniques that are not used for other types of plants. Some details are included in the individual plant profiles. Several useful resources on using water in gardens are available on the internet or are inexpensive to purchase. Some useful resources are:

No comments

Post a Comment