Plants form an essential part of the water and pond ecosystem in the garden, both aesthetically and practically. Discussing pond margin plants and bog plants, this article explores all you need to know to create the perfect setting.
Some bog plants cannot withstand totally waterlogged soil and need a certain amount of oxygen around the roots while others can be planted up in pots or containers and plunged into ponds, provided that they are stabilised at the recommended depth. This can be achieved by standing them on a platform of bricks or concrete blocks.
Both of these groups perform the all-important function of softening or breaking the line of the edge of the pond and integrating the water surface with the garden beyond. Their tranquil, serene reflections in the pond, especially when in bloom, enhance the reflective properties of the water.
Acorus gramineus (Japanese rush)
A grass-like member of the Arum lily family with variegated or golden leaves varying in height from 10cm to 40cm, depending on the variety. They are excellent pond margin plants, grown primarily for their attractive foliage; flowers are produced amongst the foliage and are seldom seen. Evergreen and cold tolerant, Acorus grows easily virtually throughout the country, and is suitable for plunge-pot culture.
Astilbe x hybrids
A clump forming perennials. Their fine, almost fern-like foliage goes completely dormant in winter, with new leaves emerging in spring followed by flower spikes bearing plumes of tiny flowers in shades of red, pink, mauve or white. Astilbe prefers rich, damp soils and semi-shaded growing conditions and does best in cool, temperate climates with high rainfall.
Chondropetalum tectorum (Thatching reed)
A popular member of the restio family originating from the Cape Province. It is a handsome plant that thrives in shallow water and grows in large clumps of up to 1,5 metres. Its slender, dark green, tubular stems are tipped with tufts of brown flowers in autumn. Suitable for plunge-pot culture, it is cold hardy, enduring and easy to grow in most parts of South Africa.
Cyperus prolifer (Dwarf papyrus)
A swamp plant found growing naturally in the coastal regions of Southern Africa. Upright stems up to a metre tall emerge from rhizomes and are topped with a tuft of fine modified leaves called sheaths. It forms large clumps and grows in water or damp soil. It is frost sensitive and is also suitable for plunge-pot culture.
A truly magnificent plant, originating from South America. It’s huge rhubarb-like leaves that grow up to 2m long, baring long, stout, prickly stems that emerge from a central crown in spring. When fully mature, Gunnera forms an awesome sight during the summer months. The clumps become extremely large, so when planting one, ensure that there is sufficient space in which it can grow and develop. Only growing in cooler regions, it does best in semi-shaded, woodland conditions on the edge of ponds or streams, in soil that remains constantly moist and damp.
Hosta x hybrids (Plantain lily)
Clump forming, deciduous perennials that are grown for their bold, colourful foliage. New leaves emerge in early spring and colours vary from green to blue-grey with numerous variegated forms, such as green with white, cream or gold. Hostas prefer the rich damp soil of bog conditions, but definitely not waterlogged soils, and do best in the cool, shaded parts of a garden in temperate climates. Tall flower spikes of white or lilac flowers emerge above the leaves in summer.
Iris Louisiana hybrids
Garden hybrids of an iris that originates from the swamps of Louisiana. They adapt well to both water and dry land conditions, needing soil rich in humus and full sun or dappled shade, and form clumps up to a meter tall. Many die down in winter but emerge early in spring to put on a spectacular display in a wide array of colours. They are suitable for plunge-pot culture.
Iris pseudacorus (Yellow flag)
A large, strong-growing iris that forms clumps of upright, sword-shaped leaves up to a meter tall. In late spring and summer flower stems produce between 4 and 12 yellow blooms. It is a durable plant that should be planted in full sun and needs a large space in which to spread unless it is contained in a submerged pot. It is spectacular and easy to grow in most climatic zones.
Lobelia cardinalis (Cardinal flower)
A clump-forming perennial with reddish-purple stems and leaves. In late spring and summer, tall flower stems are produced bearing tubular, scarlet flowers. It must be cut back hard after flowering. It performs well in rich, moist soils close to, but not in, the water and thrives in full sun or light shade, preferring the cooler climates.
Zantedeschia aethiopica (Arum lily)
The common white arum seen in both the wilds and gardens of South Africa remains one of the most impressive pond margin plants. The spectacular white spathes contrast so strikingly with the large, lush green leaves and it prefers damp soil or shallow water, in sun or light shade. In short, it is a plant suitable for plunge-pot culture that is both rewarding and easy to grow.